Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * Implement CPU time clocks for the POSIX clock interface. |
| 3 | */ |
| 4 | |
| 5 | #include <linux/sched.h> |
| 6 | #include <linux/posix-timers.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 7 | #include <linux/errno.h> |
Roman Zippel | f8bd225 | 2008-05-01 04:34:31 -0700 | [diff] [blame] | 8 | #include <linux/math64.h> |
| 9 | #include <asm/uaccess.h> |
Frank Mayhar | bb34d92 | 2008-09-12 09:54:39 -0700 | [diff] [blame] | 10 | #include <linux/kernel_stat.h> |
Xiao Guangrong | 3f0a525 | 2009-08-10 10:52:30 +0800 | [diff] [blame] | 11 | #include <trace/events/timer.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 12 | |
Frank Mayhar | f06febc | 2008-09-12 09:54:39 -0700 | [diff] [blame] | 13 | /* |
Stanislaw Gruszka | f55db60 | 2010-03-11 14:04:37 -0800 | [diff] [blame] | 14 | * Called after updating RLIMIT_CPU to run cpu timer and update |
| 15 | * tsk->signal->cputime_expires expiration cache if necessary. Needs |
| 16 | * siglock protection since other code may update expiration cache as |
| 17 | * well. |
Frank Mayhar | f06febc | 2008-09-12 09:54:39 -0700 | [diff] [blame] | 18 | */ |
Jiri Slaby | 5ab46b3 | 2009-08-28 14:05:12 +0200 | [diff] [blame] | 19 | void update_rlimit_cpu(struct task_struct *task, unsigned long rlim_new) |
Frank Mayhar | f06febc | 2008-09-12 09:54:39 -0700 | [diff] [blame] | 20 | { |
Stanislaw Gruszka | 42c4ab4 | 2009-07-29 12:15:26 +0200 | [diff] [blame] | 21 | cputime_t cputime = secs_to_cputime(rlim_new); |
Frank Mayhar | f06febc | 2008-09-12 09:54:39 -0700 | [diff] [blame] | 22 | |
Jiri Slaby | 5ab46b3 | 2009-08-28 14:05:12 +0200 | [diff] [blame] | 23 | spin_lock_irq(&task->sighand->siglock); |
| 24 | set_process_cpu_timer(task, CPUCLOCK_PROF, &cputime, NULL); |
| 25 | spin_unlock_irq(&task->sighand->siglock); |
Frank Mayhar | f06febc | 2008-09-12 09:54:39 -0700 | [diff] [blame] | 26 | } |
| 27 | |
Thomas Gleixner | a924b04 | 2006-01-09 20:52:27 -0800 | [diff] [blame] | 28 | static int check_clock(const clockid_t which_clock) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 29 | { |
| 30 | int error = 0; |
| 31 | struct task_struct *p; |
| 32 | const pid_t pid = CPUCLOCK_PID(which_clock); |
| 33 | |
| 34 | if (CPUCLOCK_WHICH(which_clock) >= CPUCLOCK_MAX) |
| 35 | return -EINVAL; |
| 36 | |
| 37 | if (pid == 0) |
| 38 | return 0; |
| 39 | |
Sergey Senozhatsky | c0deae8 | 2010-11-03 18:52:56 +0200 | [diff] [blame] | 40 | rcu_read_lock(); |
Pavel Emelyanov | 8dc86af | 2008-02-08 04:21:52 -0800 | [diff] [blame] | 41 | p = find_task_by_vpid(pid); |
Pavel Emelyanov | bac0abd | 2007-10-18 23:40:18 -0700 | [diff] [blame] | 42 | if (!p || !(CPUCLOCK_PERTHREAD(which_clock) ? |
Sergey Senozhatsky | c0deae8 | 2010-11-03 18:52:56 +0200 | [diff] [blame] | 43 | same_thread_group(p, current) : has_group_leader_pid(p))) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 44 | error = -EINVAL; |
| 45 | } |
Sergey Senozhatsky | c0deae8 | 2010-11-03 18:52:56 +0200 | [diff] [blame] | 46 | rcu_read_unlock(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 47 | |
| 48 | return error; |
| 49 | } |
| 50 | |
| 51 | static inline union cpu_time_count |
Thomas Gleixner | a924b04 | 2006-01-09 20:52:27 -0800 | [diff] [blame] | 52 | timespec_to_sample(const clockid_t which_clock, const struct timespec *tp) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 53 | { |
| 54 | union cpu_time_count ret; |
| 55 | ret.sched = 0; /* high half always zero when .cpu used */ |
| 56 | if (CPUCLOCK_WHICH(which_clock) == CPUCLOCK_SCHED) { |
Oleg Nesterov | ee500f2 | 2005-11-28 13:43:55 -0800 | [diff] [blame] | 57 | ret.sched = (unsigned long long)tp->tv_sec * NSEC_PER_SEC + tp->tv_nsec; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 58 | } else { |
| 59 | ret.cpu = timespec_to_cputime(tp); |
| 60 | } |
| 61 | return ret; |
| 62 | } |
| 63 | |
Thomas Gleixner | a924b04 | 2006-01-09 20:52:27 -0800 | [diff] [blame] | 64 | static void sample_to_timespec(const clockid_t which_clock, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 65 | union cpu_time_count cpu, |
| 66 | struct timespec *tp) |
| 67 | { |
Roman Zippel | f8bd225 | 2008-05-01 04:34:31 -0700 | [diff] [blame] | 68 | if (CPUCLOCK_WHICH(which_clock) == CPUCLOCK_SCHED) |
| 69 | *tp = ns_to_timespec(cpu.sched); |
| 70 | else |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 71 | cputime_to_timespec(cpu.cpu, tp); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 72 | } |
| 73 | |
Thomas Gleixner | a924b04 | 2006-01-09 20:52:27 -0800 | [diff] [blame] | 74 | static inline int cpu_time_before(const clockid_t which_clock, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 75 | union cpu_time_count now, |
| 76 | union cpu_time_count then) |
| 77 | { |
| 78 | if (CPUCLOCK_WHICH(which_clock) == CPUCLOCK_SCHED) { |
| 79 | return now.sched < then.sched; |
| 80 | } else { |
| 81 | return cputime_lt(now.cpu, then.cpu); |
| 82 | } |
| 83 | } |
Thomas Gleixner | a924b04 | 2006-01-09 20:52:27 -0800 | [diff] [blame] | 84 | static inline void cpu_time_add(const clockid_t which_clock, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 85 | union cpu_time_count *acc, |
| 86 | union cpu_time_count val) |
| 87 | { |
| 88 | if (CPUCLOCK_WHICH(which_clock) == CPUCLOCK_SCHED) { |
| 89 | acc->sched += val.sched; |
| 90 | } else { |
| 91 | acc->cpu = cputime_add(acc->cpu, val.cpu); |
| 92 | } |
| 93 | } |
Thomas Gleixner | a924b04 | 2006-01-09 20:52:27 -0800 | [diff] [blame] | 94 | static inline union cpu_time_count cpu_time_sub(const clockid_t which_clock, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 95 | union cpu_time_count a, |
| 96 | union cpu_time_count b) |
| 97 | { |
| 98 | if (CPUCLOCK_WHICH(which_clock) == CPUCLOCK_SCHED) { |
| 99 | a.sched -= b.sched; |
| 100 | } else { |
| 101 | a.cpu = cputime_sub(a.cpu, b.cpu); |
| 102 | } |
| 103 | return a; |
| 104 | } |
| 105 | |
| 106 | /* |
Thomas Gleixner | ac08c26 | 2006-10-17 00:09:39 -0700 | [diff] [blame] | 107 | * Divide and limit the result to res >= 1 |
| 108 | * |
| 109 | * This is necessary to prevent signal delivery starvation, when the result of |
| 110 | * the division would be rounded down to 0. |
| 111 | */ |
| 112 | static inline cputime_t cputime_div_non_zero(cputime_t time, unsigned long div) |
| 113 | { |
| 114 | cputime_t res = cputime_div(time, div); |
| 115 | |
| 116 | return max_t(cputime_t, res, 1); |
| 117 | } |
| 118 | |
| 119 | /* |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 120 | * Update expiry time from increment, and increase overrun count, |
| 121 | * given the current clock sample. |
| 122 | */ |
Oleg Nesterov | 7a4ed93 | 2005-10-26 20:26:53 +0400 | [diff] [blame] | 123 | static void bump_cpu_timer(struct k_itimer *timer, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 124 | union cpu_time_count now) |
| 125 | { |
| 126 | int i; |
| 127 | |
| 128 | if (timer->it.cpu.incr.sched == 0) |
| 129 | return; |
| 130 | |
| 131 | if (CPUCLOCK_WHICH(timer->it_clock) == CPUCLOCK_SCHED) { |
| 132 | unsigned long long delta, incr; |
| 133 | |
| 134 | if (now.sched < timer->it.cpu.expires.sched) |
| 135 | return; |
| 136 | incr = timer->it.cpu.incr.sched; |
| 137 | delta = now.sched + incr - timer->it.cpu.expires.sched; |
| 138 | /* Don't use (incr*2 < delta), incr*2 might overflow. */ |
| 139 | for (i = 0; incr < delta - incr; i++) |
| 140 | incr = incr << 1; |
| 141 | for (; i >= 0; incr >>= 1, i--) { |
Oleg Nesterov | 7a4ed93 | 2005-10-26 20:26:53 +0400 | [diff] [blame] | 142 | if (delta < incr) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 143 | continue; |
| 144 | timer->it.cpu.expires.sched += incr; |
| 145 | timer->it_overrun += 1 << i; |
| 146 | delta -= incr; |
| 147 | } |
| 148 | } else { |
| 149 | cputime_t delta, incr; |
| 150 | |
| 151 | if (cputime_lt(now.cpu, timer->it.cpu.expires.cpu)) |
| 152 | return; |
| 153 | incr = timer->it.cpu.incr.cpu; |
| 154 | delta = cputime_sub(cputime_add(now.cpu, incr), |
| 155 | timer->it.cpu.expires.cpu); |
| 156 | /* Don't use (incr*2 < delta), incr*2 might overflow. */ |
| 157 | for (i = 0; cputime_lt(incr, cputime_sub(delta, incr)); i++) |
| 158 | incr = cputime_add(incr, incr); |
| 159 | for (; i >= 0; incr = cputime_halve(incr), i--) { |
Oleg Nesterov | 7a4ed93 | 2005-10-26 20:26:53 +0400 | [diff] [blame] | 160 | if (cputime_lt(delta, incr)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 161 | continue; |
| 162 | timer->it.cpu.expires.cpu = |
| 163 | cputime_add(timer->it.cpu.expires.cpu, incr); |
| 164 | timer->it_overrun += 1 << i; |
| 165 | delta = cputime_sub(delta, incr); |
| 166 | } |
| 167 | } |
| 168 | } |
| 169 | |
| 170 | static inline cputime_t prof_ticks(struct task_struct *p) |
| 171 | { |
| 172 | return cputime_add(p->utime, p->stime); |
| 173 | } |
| 174 | static inline cputime_t virt_ticks(struct task_struct *p) |
| 175 | { |
| 176 | return p->utime; |
| 177 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 178 | |
Thomas Gleixner | a924b04 | 2006-01-09 20:52:27 -0800 | [diff] [blame] | 179 | int posix_cpu_clock_getres(const clockid_t which_clock, struct timespec *tp) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 180 | { |
| 181 | int error = check_clock(which_clock); |
| 182 | if (!error) { |
| 183 | tp->tv_sec = 0; |
| 184 | tp->tv_nsec = ((NSEC_PER_SEC + HZ - 1) / HZ); |
| 185 | if (CPUCLOCK_WHICH(which_clock) == CPUCLOCK_SCHED) { |
| 186 | /* |
| 187 | * If sched_clock is using a cycle counter, we |
| 188 | * don't have any idea of its true resolution |
| 189 | * exported, but it is much more than 1s/HZ. |
| 190 | */ |
| 191 | tp->tv_nsec = 1; |
| 192 | } |
| 193 | } |
| 194 | return error; |
| 195 | } |
| 196 | |
Thomas Gleixner | a924b04 | 2006-01-09 20:52:27 -0800 | [diff] [blame] | 197 | int posix_cpu_clock_set(const clockid_t which_clock, const struct timespec *tp) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 198 | { |
| 199 | /* |
| 200 | * You can never reset a CPU clock, but we check for other errors |
| 201 | * in the call before failing with EPERM. |
| 202 | */ |
| 203 | int error = check_clock(which_clock); |
| 204 | if (error == 0) { |
| 205 | error = -EPERM; |
| 206 | } |
| 207 | return error; |
| 208 | } |
| 209 | |
| 210 | |
| 211 | /* |
| 212 | * Sample a per-thread clock for the given task. |
| 213 | */ |
Thomas Gleixner | a924b04 | 2006-01-09 20:52:27 -0800 | [diff] [blame] | 214 | static int cpu_clock_sample(const clockid_t which_clock, struct task_struct *p, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 215 | union cpu_time_count *cpu) |
| 216 | { |
| 217 | switch (CPUCLOCK_WHICH(which_clock)) { |
| 218 | default: |
| 219 | return -EINVAL; |
| 220 | case CPUCLOCK_PROF: |
| 221 | cpu->cpu = prof_ticks(p); |
| 222 | break; |
| 223 | case CPUCLOCK_VIRT: |
| 224 | cpu->cpu = virt_ticks(p); |
| 225 | break; |
| 226 | case CPUCLOCK_SCHED: |
Hidetoshi Seto | c5f8d99 | 2009-03-31 16:56:03 +0900 | [diff] [blame] | 227 | cpu->sched = task_sched_runtime(p); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 228 | break; |
| 229 | } |
| 230 | return 0; |
| 231 | } |
| 232 | |
Peter Zijlstra | 4cd4c1b | 2009-02-05 12:24:16 +0100 | [diff] [blame] | 233 | void thread_group_cputime(struct task_struct *tsk, struct task_cputime *times) |
| 234 | { |
Oleg Nesterov | bfac700 | 2010-06-11 01:09:56 +0200 | [diff] [blame] | 235 | struct signal_struct *sig = tsk->signal; |
Peter Zijlstra | 4cd4c1b | 2009-02-05 12:24:16 +0100 | [diff] [blame] | 236 | struct task_struct *t; |
| 237 | |
Oleg Nesterov | bfac700 | 2010-06-11 01:09:56 +0200 | [diff] [blame] | 238 | times->utime = sig->utime; |
| 239 | times->stime = sig->stime; |
| 240 | times->sum_exec_runtime = sig->sum_sched_runtime; |
Peter Zijlstra | 4cd4c1b | 2009-02-05 12:24:16 +0100 | [diff] [blame] | 241 | |
| 242 | rcu_read_lock(); |
Oleg Nesterov | bfac700 | 2010-06-11 01:09:56 +0200 | [diff] [blame] | 243 | /* make sure we can trust tsk->thread_group list */ |
| 244 | if (!likely(pid_alive(tsk))) |
Peter Zijlstra | 4cd4c1b | 2009-02-05 12:24:16 +0100 | [diff] [blame] | 245 | goto out; |
| 246 | |
Peter Zijlstra | 4cd4c1b | 2009-02-05 12:24:16 +0100 | [diff] [blame] | 247 | t = tsk; |
| 248 | do { |
| 249 | times->utime = cputime_add(times->utime, t->utime); |
| 250 | times->stime = cputime_add(times->stime, t->stime); |
| 251 | times->sum_exec_runtime += t->se.sum_exec_runtime; |
Oleg Nesterov | bfac700 | 2010-06-11 01:09:56 +0200 | [diff] [blame] | 252 | } while_each_thread(tsk, t); |
Peter Zijlstra | 4cd4c1b | 2009-02-05 12:24:16 +0100 | [diff] [blame] | 253 | out: |
| 254 | rcu_read_unlock(); |
| 255 | } |
| 256 | |
Peter Zijlstra | 4da94d49 | 2009-02-11 11:30:27 +0100 | [diff] [blame] | 257 | static void update_gt_cputime(struct task_cputime *a, struct task_cputime *b) |
| 258 | { |
| 259 | if (cputime_gt(b->utime, a->utime)) |
| 260 | a->utime = b->utime; |
| 261 | |
| 262 | if (cputime_gt(b->stime, a->stime)) |
| 263 | a->stime = b->stime; |
| 264 | |
| 265 | if (b->sum_exec_runtime > a->sum_exec_runtime) |
| 266 | a->sum_exec_runtime = b->sum_exec_runtime; |
| 267 | } |
| 268 | |
| 269 | void thread_group_cputimer(struct task_struct *tsk, struct task_cputime *times) |
| 270 | { |
| 271 | struct thread_group_cputimer *cputimer = &tsk->signal->cputimer; |
| 272 | struct task_cputime sum; |
| 273 | unsigned long flags; |
| 274 | |
| 275 | spin_lock_irqsave(&cputimer->lock, flags); |
| 276 | if (!cputimer->running) { |
| 277 | cputimer->running = 1; |
| 278 | /* |
| 279 | * The POSIX timer interface allows for absolute time expiry |
| 280 | * values through the TIMER_ABSTIME flag, therefore we have |
| 281 | * to synchronize the timer to the clock every time we start |
| 282 | * it. |
| 283 | */ |
| 284 | thread_group_cputime(tsk, &sum); |
| 285 | update_gt_cputime(&cputimer->cputime, &sum); |
| 286 | } |
| 287 | *times = cputimer->cputime; |
| 288 | spin_unlock_irqrestore(&cputimer->lock, flags); |
| 289 | } |
| 290 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 291 | /* |
| 292 | * Sample a process (thread group) clock for the given group_leader task. |
| 293 | * Must be called with tasklist_lock held for reading. |
| 294 | */ |
Thomas Gleixner | a924b04 | 2006-01-09 20:52:27 -0800 | [diff] [blame] | 295 | static int cpu_clock_sample_group(const clockid_t which_clock, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 296 | struct task_struct *p, |
| 297 | union cpu_time_count *cpu) |
| 298 | { |
Frank Mayhar | bb34d92 | 2008-09-12 09:54:39 -0700 | [diff] [blame] | 299 | struct task_cputime cputime; |
| 300 | |
Petr Tesarik | eccdaea | 2008-11-24 15:46:31 +0100 | [diff] [blame] | 301 | switch (CPUCLOCK_WHICH(which_clock)) { |
Frank Mayhar | bb34d92 | 2008-09-12 09:54:39 -0700 | [diff] [blame] | 302 | default: |
| 303 | return -EINVAL; |
| 304 | case CPUCLOCK_PROF: |
Hidetoshi Seto | c5f8d99 | 2009-03-31 16:56:03 +0900 | [diff] [blame] | 305 | thread_group_cputime(p, &cputime); |
Frank Mayhar | bb34d92 | 2008-09-12 09:54:39 -0700 | [diff] [blame] | 306 | cpu->cpu = cputime_add(cputime.utime, cputime.stime); |
| 307 | break; |
| 308 | case CPUCLOCK_VIRT: |
Hidetoshi Seto | c5f8d99 | 2009-03-31 16:56:03 +0900 | [diff] [blame] | 309 | thread_group_cputime(p, &cputime); |
Frank Mayhar | bb34d92 | 2008-09-12 09:54:39 -0700 | [diff] [blame] | 310 | cpu->cpu = cputime.utime; |
| 311 | break; |
| 312 | case CPUCLOCK_SCHED: |
Hidetoshi Seto | c5f8d99 | 2009-03-31 16:56:03 +0900 | [diff] [blame] | 313 | cpu->sched = thread_group_sched_runtime(p); |
Frank Mayhar | bb34d92 | 2008-09-12 09:54:39 -0700 | [diff] [blame] | 314 | break; |
| 315 | } |
| 316 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 317 | } |
| 318 | |
| 319 | |
Thomas Gleixner | a924b04 | 2006-01-09 20:52:27 -0800 | [diff] [blame] | 320 | int posix_cpu_clock_get(const clockid_t which_clock, struct timespec *tp) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 321 | { |
| 322 | const pid_t pid = CPUCLOCK_PID(which_clock); |
| 323 | int error = -EINVAL; |
| 324 | union cpu_time_count rtn; |
| 325 | |
| 326 | if (pid == 0) { |
| 327 | /* |
| 328 | * Special case constant value for our own clocks. |
| 329 | * We don't have to do any lookup to find ourselves. |
| 330 | */ |
| 331 | if (CPUCLOCK_PERTHREAD(which_clock)) { |
| 332 | /* |
| 333 | * Sampling just ourselves we can do with no locking. |
| 334 | */ |
| 335 | error = cpu_clock_sample(which_clock, |
| 336 | current, &rtn); |
| 337 | } else { |
| 338 | read_lock(&tasklist_lock); |
| 339 | error = cpu_clock_sample_group(which_clock, |
| 340 | current, &rtn); |
| 341 | read_unlock(&tasklist_lock); |
| 342 | } |
| 343 | } else { |
| 344 | /* |
| 345 | * Find the given PID, and validate that the caller |
| 346 | * should be able to see it. |
| 347 | */ |
| 348 | struct task_struct *p; |
Paul E. McKenney | 1f2ea08 | 2007-02-16 01:28:22 -0800 | [diff] [blame] | 349 | rcu_read_lock(); |
Pavel Emelyanov | 8dc86af | 2008-02-08 04:21:52 -0800 | [diff] [blame] | 350 | p = find_task_by_vpid(pid); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 351 | if (p) { |
| 352 | if (CPUCLOCK_PERTHREAD(which_clock)) { |
Pavel Emelyanov | bac0abd | 2007-10-18 23:40:18 -0700 | [diff] [blame] | 353 | if (same_thread_group(p, current)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 354 | error = cpu_clock_sample(which_clock, |
| 355 | p, &rtn); |
| 356 | } |
Paul E. McKenney | 1f2ea08 | 2007-02-16 01:28:22 -0800 | [diff] [blame] | 357 | } else { |
| 358 | read_lock(&tasklist_lock); |
Oleg Nesterov | d30fda3 | 2010-05-26 14:43:13 -0700 | [diff] [blame] | 359 | if (thread_group_leader(p) && p->sighand) { |
Paul E. McKenney | 1f2ea08 | 2007-02-16 01:28:22 -0800 | [diff] [blame] | 360 | error = |
| 361 | cpu_clock_sample_group(which_clock, |
| 362 | p, &rtn); |
| 363 | } |
| 364 | read_unlock(&tasklist_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 365 | } |
| 366 | } |
Paul E. McKenney | 1f2ea08 | 2007-02-16 01:28:22 -0800 | [diff] [blame] | 367 | rcu_read_unlock(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 368 | } |
| 369 | |
| 370 | if (error) |
| 371 | return error; |
| 372 | sample_to_timespec(which_clock, rtn, tp); |
| 373 | return 0; |
| 374 | } |
| 375 | |
| 376 | |
| 377 | /* |
| 378 | * Validate the clockid_t for a new CPU-clock timer, and initialize the timer. |
Stanislaw Gruszka | ba5ea95 | 2009-11-17 14:14:13 -0800 | [diff] [blame] | 379 | * This is called from sys_timer_create() and do_cpu_nanosleep() with the |
| 380 | * new timer already all-zeros initialized. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 381 | */ |
| 382 | int posix_cpu_timer_create(struct k_itimer *new_timer) |
| 383 | { |
| 384 | int ret = 0; |
| 385 | const pid_t pid = CPUCLOCK_PID(new_timer->it_clock); |
| 386 | struct task_struct *p; |
| 387 | |
| 388 | if (CPUCLOCK_WHICH(new_timer->it_clock) >= CPUCLOCK_MAX) |
| 389 | return -EINVAL; |
| 390 | |
| 391 | INIT_LIST_HEAD(&new_timer->it.cpu.entry); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 392 | |
Sergey Senozhatsky | c0deae8 | 2010-11-03 18:52:56 +0200 | [diff] [blame] | 393 | rcu_read_lock(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 394 | if (CPUCLOCK_PERTHREAD(new_timer->it_clock)) { |
| 395 | if (pid == 0) { |
| 396 | p = current; |
| 397 | } else { |
Pavel Emelyanov | 8dc86af | 2008-02-08 04:21:52 -0800 | [diff] [blame] | 398 | p = find_task_by_vpid(pid); |
Pavel Emelyanov | bac0abd | 2007-10-18 23:40:18 -0700 | [diff] [blame] | 399 | if (p && !same_thread_group(p, current)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 400 | p = NULL; |
| 401 | } |
| 402 | } else { |
| 403 | if (pid == 0) { |
| 404 | p = current->group_leader; |
| 405 | } else { |
Pavel Emelyanov | 8dc86af | 2008-02-08 04:21:52 -0800 | [diff] [blame] | 406 | p = find_task_by_vpid(pid); |
Sergey Senozhatsky | c0deae8 | 2010-11-03 18:52:56 +0200 | [diff] [blame] | 407 | if (p && !has_group_leader_pid(p)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 408 | p = NULL; |
| 409 | } |
| 410 | } |
| 411 | new_timer->it.cpu.task = p; |
| 412 | if (p) { |
| 413 | get_task_struct(p); |
| 414 | } else { |
| 415 | ret = -EINVAL; |
| 416 | } |
Sergey Senozhatsky | c0deae8 | 2010-11-03 18:52:56 +0200 | [diff] [blame] | 417 | rcu_read_unlock(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 418 | |
| 419 | return ret; |
| 420 | } |
| 421 | |
| 422 | /* |
| 423 | * Clean up a CPU-clock timer that is about to be destroyed. |
| 424 | * This is called from timer deletion with the timer already locked. |
| 425 | * If we return TIMER_RETRY, it's necessary to release the timer's lock |
| 426 | * and try again. (This happens when the timer is in the middle of firing.) |
| 427 | */ |
| 428 | int posix_cpu_timer_del(struct k_itimer *timer) |
| 429 | { |
| 430 | struct task_struct *p = timer->it.cpu.task; |
Oleg Nesterov | 108150e | 2005-10-23 20:25:39 +0400 | [diff] [blame] | 431 | int ret = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 432 | |
Oleg Nesterov | 108150e | 2005-10-23 20:25:39 +0400 | [diff] [blame] | 433 | if (likely(p != NULL)) { |
Linus Torvalds | 9465bee | 2005-10-21 15:36:00 -0700 | [diff] [blame] | 434 | read_lock(&tasklist_lock); |
Oleg Nesterov | d30fda3 | 2010-05-26 14:43:13 -0700 | [diff] [blame] | 435 | if (unlikely(p->sighand == NULL)) { |
Linus Torvalds | 9465bee | 2005-10-21 15:36:00 -0700 | [diff] [blame] | 436 | /* |
| 437 | * We raced with the reaping of the task. |
| 438 | * The deletion should have cleared us off the list. |
| 439 | */ |
| 440 | BUG_ON(!list_empty(&timer->it.cpu.entry)); |
| 441 | } else { |
Linus Torvalds | 9465bee | 2005-10-21 15:36:00 -0700 | [diff] [blame] | 442 | spin_lock(&p->sighand->siglock); |
Oleg Nesterov | 108150e | 2005-10-23 20:25:39 +0400 | [diff] [blame] | 443 | if (timer->it.cpu.firing) |
| 444 | ret = TIMER_RETRY; |
| 445 | else |
| 446 | list_del(&timer->it.cpu.entry); |
Linus Torvalds | 9465bee | 2005-10-21 15:36:00 -0700 | [diff] [blame] | 447 | spin_unlock(&p->sighand->siglock); |
| 448 | } |
| 449 | read_unlock(&tasklist_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 450 | |
Oleg Nesterov | 108150e | 2005-10-23 20:25:39 +0400 | [diff] [blame] | 451 | if (!ret) |
| 452 | put_task_struct(p); |
| 453 | } |
| 454 | |
| 455 | return ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 456 | } |
| 457 | |
| 458 | /* |
| 459 | * Clean out CPU timers still ticking when a thread exited. The task |
| 460 | * pointer is cleared, and the expiry time is replaced with the residual |
| 461 | * time for later timer_gettime calls to return. |
| 462 | * This must be called with the siglock held. |
| 463 | */ |
| 464 | static void cleanup_timers(struct list_head *head, |
| 465 | cputime_t utime, cputime_t stime, |
Ingo Molnar | 41b86e9 | 2007-07-09 18:51:58 +0200 | [diff] [blame] | 466 | unsigned long long sum_exec_runtime) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 467 | { |
| 468 | struct cpu_timer_list *timer, *next; |
| 469 | cputime_t ptime = cputime_add(utime, stime); |
| 470 | |
| 471 | list_for_each_entry_safe(timer, next, head, entry) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 472 | list_del_init(&timer->entry); |
| 473 | if (cputime_lt(timer->expires.cpu, ptime)) { |
| 474 | timer->expires.cpu = cputime_zero; |
| 475 | } else { |
| 476 | timer->expires.cpu = cputime_sub(timer->expires.cpu, |
| 477 | ptime); |
| 478 | } |
| 479 | } |
| 480 | |
| 481 | ++head; |
| 482 | list_for_each_entry_safe(timer, next, head, entry) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 483 | list_del_init(&timer->entry); |
| 484 | if (cputime_lt(timer->expires.cpu, utime)) { |
| 485 | timer->expires.cpu = cputime_zero; |
| 486 | } else { |
| 487 | timer->expires.cpu = cputime_sub(timer->expires.cpu, |
| 488 | utime); |
| 489 | } |
| 490 | } |
| 491 | |
| 492 | ++head; |
| 493 | list_for_each_entry_safe(timer, next, head, entry) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 494 | list_del_init(&timer->entry); |
Ingo Molnar | 41b86e9 | 2007-07-09 18:51:58 +0200 | [diff] [blame] | 495 | if (timer->expires.sched < sum_exec_runtime) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 496 | timer->expires.sched = 0; |
| 497 | } else { |
Ingo Molnar | 41b86e9 | 2007-07-09 18:51:58 +0200 | [diff] [blame] | 498 | timer->expires.sched -= sum_exec_runtime; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 499 | } |
| 500 | } |
| 501 | } |
| 502 | |
| 503 | /* |
| 504 | * These are both called with the siglock held, when the current thread |
| 505 | * is being reaped. When the final (leader) thread in the group is reaped, |
| 506 | * posix_cpu_timers_exit_group will be called after posix_cpu_timers_exit. |
| 507 | */ |
| 508 | void posix_cpu_timers_exit(struct task_struct *tsk) |
| 509 | { |
| 510 | cleanup_timers(tsk->cpu_timers, |
Ingo Molnar | 41b86e9 | 2007-07-09 18:51:58 +0200 | [diff] [blame] | 511 | tsk->utime, tsk->stime, tsk->se.sum_exec_runtime); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 512 | |
| 513 | } |
| 514 | void posix_cpu_timers_exit_group(struct task_struct *tsk) |
| 515 | { |
Stanislaw Gruszka | 17d42c1 | 2009-08-06 16:03:30 -0700 | [diff] [blame] | 516 | struct signal_struct *const sig = tsk->signal; |
Frank Mayhar | f06febc | 2008-09-12 09:54:39 -0700 | [diff] [blame] | 517 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 518 | cleanup_timers(tsk->signal->cpu_timers, |
Stanislaw Gruszka | 17d42c1 | 2009-08-06 16:03:30 -0700 | [diff] [blame] | 519 | cputime_add(tsk->utime, sig->utime), |
| 520 | cputime_add(tsk->stime, sig->stime), |
| 521 | tsk->se.sum_exec_runtime + sig->sum_sched_runtime); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 522 | } |
| 523 | |
| 524 | static void clear_dead_task(struct k_itimer *timer, union cpu_time_count now) |
| 525 | { |
| 526 | /* |
| 527 | * That's all for this thread or process. |
| 528 | * We leave our residual in expires to be reported. |
| 529 | */ |
| 530 | put_task_struct(timer->it.cpu.task); |
| 531 | timer->it.cpu.task = NULL; |
| 532 | timer->it.cpu.expires = cpu_time_sub(timer->it_clock, |
| 533 | timer->it.cpu.expires, |
| 534 | now); |
| 535 | } |
| 536 | |
Stanislaw Gruszka | d1e3b6d | 2009-07-29 12:15:28 +0200 | [diff] [blame] | 537 | static inline int expires_gt(cputime_t expires, cputime_t new_exp) |
| 538 | { |
| 539 | return cputime_eq(expires, cputime_zero) || |
| 540 | cputime_gt(expires, new_exp); |
| 541 | } |
| 542 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 543 | /* |
| 544 | * Insert the timer on the appropriate list before any timers that |
| 545 | * expire later. This must be called with the tasklist_lock held |
Stanislaw Gruszka | c287393 | 2010-03-11 14:04:42 -0800 | [diff] [blame] | 546 | * for reading, interrupts disabled and p->sighand->siglock taken. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 547 | */ |
Stanislaw Gruszka | 5eb9aa6 | 2010-03-11 14:04:38 -0800 | [diff] [blame] | 548 | static void arm_timer(struct k_itimer *timer) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 549 | { |
| 550 | struct task_struct *p = timer->it.cpu.task; |
| 551 | struct list_head *head, *listpos; |
Stanislaw Gruszka | 5eb9aa6 | 2010-03-11 14:04:38 -0800 | [diff] [blame] | 552 | struct task_cputime *cputime_expires; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 553 | struct cpu_timer_list *const nt = &timer->it.cpu; |
| 554 | struct cpu_timer_list *next; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 555 | |
Stanislaw Gruszka | 5eb9aa6 | 2010-03-11 14:04:38 -0800 | [diff] [blame] | 556 | if (CPUCLOCK_PERTHREAD(timer->it_clock)) { |
| 557 | head = p->cpu_timers; |
| 558 | cputime_expires = &p->cputime_expires; |
| 559 | } else { |
| 560 | head = p->signal->cpu_timers; |
| 561 | cputime_expires = &p->signal->cputime_expires; |
| 562 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 563 | head += CPUCLOCK_WHICH(timer->it_clock); |
| 564 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 565 | listpos = head; |
Stanislaw Gruszka | 5eb9aa6 | 2010-03-11 14:04:38 -0800 | [diff] [blame] | 566 | list_for_each_entry(next, head, entry) { |
| 567 | if (cpu_time_before(timer->it_clock, nt->expires, next->expires)) |
| 568 | break; |
| 569 | listpos = &next->entry; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 570 | } |
| 571 | list_add(&nt->entry, listpos); |
| 572 | |
| 573 | if (listpos == head) { |
Stanislaw Gruszka | 5eb9aa6 | 2010-03-11 14:04:38 -0800 | [diff] [blame] | 574 | union cpu_time_count *exp = &nt->expires; |
| 575 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 576 | /* |
Stanislaw Gruszka | 5eb9aa6 | 2010-03-11 14:04:38 -0800 | [diff] [blame] | 577 | * We are the new earliest-expiring POSIX 1.b timer, hence |
| 578 | * need to update expiration cache. Take into account that |
| 579 | * for process timers we share expiration cache with itimers |
| 580 | * and RLIMIT_CPU and for thread timers with RLIMIT_RTTIME. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 581 | */ |
| 582 | |
Stanislaw Gruszka | 5eb9aa6 | 2010-03-11 14:04:38 -0800 | [diff] [blame] | 583 | switch (CPUCLOCK_WHICH(timer->it_clock)) { |
| 584 | case CPUCLOCK_PROF: |
| 585 | if (expires_gt(cputime_expires->prof_exp, exp->cpu)) |
| 586 | cputime_expires->prof_exp = exp->cpu; |
| 587 | break; |
| 588 | case CPUCLOCK_VIRT: |
| 589 | if (expires_gt(cputime_expires->virt_exp, exp->cpu)) |
| 590 | cputime_expires->virt_exp = exp->cpu; |
| 591 | break; |
| 592 | case CPUCLOCK_SCHED: |
| 593 | if (cputime_expires->sched_exp == 0 || |
| 594 | cputime_expires->sched_exp > exp->sched) |
| 595 | cputime_expires->sched_exp = exp->sched; |
| 596 | break; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 597 | } |
| 598 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 599 | } |
| 600 | |
| 601 | /* |
| 602 | * The timer is locked, fire it and arrange for its reload. |
| 603 | */ |
| 604 | static void cpu_timer_fire(struct k_itimer *timer) |
| 605 | { |
Stanislaw Gruszka | 1f169f8 | 2010-03-11 14:04:41 -0800 | [diff] [blame] | 606 | if ((timer->it_sigev_notify & ~SIGEV_THREAD_ID) == SIGEV_NONE) { |
| 607 | /* |
| 608 | * User don't want any signal. |
| 609 | */ |
| 610 | timer->it.cpu.expires.sched = 0; |
| 611 | } else if (unlikely(timer->sigq == NULL)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 612 | /* |
| 613 | * This a special case for clock_nanosleep, |
| 614 | * not a normal timer from sys_timer_create. |
| 615 | */ |
| 616 | wake_up_process(timer->it_process); |
| 617 | timer->it.cpu.expires.sched = 0; |
| 618 | } else if (timer->it.cpu.incr.sched == 0) { |
| 619 | /* |
| 620 | * One-shot timer. Clear it as soon as it's fired. |
| 621 | */ |
| 622 | posix_timer_event(timer, 0); |
| 623 | timer->it.cpu.expires.sched = 0; |
| 624 | } else if (posix_timer_event(timer, ++timer->it_requeue_pending)) { |
| 625 | /* |
| 626 | * The signal did not get queued because the signal |
| 627 | * was ignored, so we won't get any callback to |
| 628 | * reload the timer. But we need to keep it |
| 629 | * ticking in case the signal is deliverable next time. |
| 630 | */ |
| 631 | posix_cpu_timer_schedule(timer); |
| 632 | } |
| 633 | } |
| 634 | |
| 635 | /* |
Peter Zijlstra | 3997ad3 | 2009-02-12 15:00:52 +0100 | [diff] [blame] | 636 | * Sample a process (thread group) timer for the given group_leader task. |
| 637 | * Must be called with tasklist_lock held for reading. |
| 638 | */ |
| 639 | static int cpu_timer_sample_group(const clockid_t which_clock, |
| 640 | struct task_struct *p, |
| 641 | union cpu_time_count *cpu) |
| 642 | { |
| 643 | struct task_cputime cputime; |
| 644 | |
| 645 | thread_group_cputimer(p, &cputime); |
| 646 | switch (CPUCLOCK_WHICH(which_clock)) { |
| 647 | default: |
| 648 | return -EINVAL; |
| 649 | case CPUCLOCK_PROF: |
| 650 | cpu->cpu = cputime_add(cputime.utime, cputime.stime); |
| 651 | break; |
| 652 | case CPUCLOCK_VIRT: |
| 653 | cpu->cpu = cputime.utime; |
| 654 | break; |
| 655 | case CPUCLOCK_SCHED: |
| 656 | cpu->sched = cputime.sum_exec_runtime + task_delta_exec(p); |
| 657 | break; |
| 658 | } |
| 659 | return 0; |
| 660 | } |
| 661 | |
| 662 | /* |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 663 | * Guts of sys_timer_settime for CPU timers. |
| 664 | * This is called with the timer locked and interrupts disabled. |
| 665 | * If we return TIMER_RETRY, it's necessary to release the timer's lock |
| 666 | * and try again. (This happens when the timer is in the middle of firing.) |
| 667 | */ |
| 668 | int posix_cpu_timer_set(struct k_itimer *timer, int flags, |
| 669 | struct itimerspec *new, struct itimerspec *old) |
| 670 | { |
| 671 | struct task_struct *p = timer->it.cpu.task; |
Stanislaw Gruszka | ae1a78e | 2010-03-11 14:04:39 -0800 | [diff] [blame] | 672 | union cpu_time_count old_expires, new_expires, old_incr, val; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 673 | int ret; |
| 674 | |
| 675 | if (unlikely(p == NULL)) { |
| 676 | /* |
| 677 | * Timer refers to a dead task's clock. |
| 678 | */ |
| 679 | return -ESRCH; |
| 680 | } |
| 681 | |
| 682 | new_expires = timespec_to_sample(timer->it_clock, &new->it_value); |
| 683 | |
| 684 | read_lock(&tasklist_lock); |
| 685 | /* |
| 686 | * We need the tasklist_lock to protect against reaping that |
Oleg Nesterov | d30fda3 | 2010-05-26 14:43:13 -0700 | [diff] [blame] | 687 | * clears p->sighand. If p has just been reaped, we can no |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 688 | * longer get any information about it at all. |
| 689 | */ |
Oleg Nesterov | d30fda3 | 2010-05-26 14:43:13 -0700 | [diff] [blame] | 690 | if (unlikely(p->sighand == NULL)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 691 | read_unlock(&tasklist_lock); |
| 692 | put_task_struct(p); |
| 693 | timer->it.cpu.task = NULL; |
| 694 | return -ESRCH; |
| 695 | } |
| 696 | |
| 697 | /* |
| 698 | * Disarm any old timer after extracting its expiry time. |
| 699 | */ |
| 700 | BUG_ON(!irqs_disabled()); |
Oleg Nesterov | a69ac4a | 2005-10-24 18:29:58 +0400 | [diff] [blame] | 701 | |
| 702 | ret = 0; |
Stanislaw Gruszka | ae1a78e | 2010-03-11 14:04:39 -0800 | [diff] [blame] | 703 | old_incr = timer->it.cpu.incr; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 704 | spin_lock(&p->sighand->siglock); |
| 705 | old_expires = timer->it.cpu.expires; |
Oleg Nesterov | a69ac4a | 2005-10-24 18:29:58 +0400 | [diff] [blame] | 706 | if (unlikely(timer->it.cpu.firing)) { |
| 707 | timer->it.cpu.firing = -1; |
| 708 | ret = TIMER_RETRY; |
| 709 | } else |
| 710 | list_del_init(&timer->it.cpu.entry); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 711 | |
| 712 | /* |
| 713 | * We need to sample the current value to convert the new |
| 714 | * value from to relative and absolute, and to convert the |
| 715 | * old value from absolute to relative. To set a process |
| 716 | * timer, we need a sample to balance the thread expiry |
| 717 | * times (in arm_timer). With an absolute time, we must |
| 718 | * check if it's already passed. In short, we need a sample. |
| 719 | */ |
| 720 | if (CPUCLOCK_PERTHREAD(timer->it_clock)) { |
| 721 | cpu_clock_sample(timer->it_clock, p, &val); |
| 722 | } else { |
Peter Zijlstra | 3997ad3 | 2009-02-12 15:00:52 +0100 | [diff] [blame] | 723 | cpu_timer_sample_group(timer->it_clock, p, &val); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 724 | } |
| 725 | |
| 726 | if (old) { |
| 727 | if (old_expires.sched == 0) { |
| 728 | old->it_value.tv_sec = 0; |
| 729 | old->it_value.tv_nsec = 0; |
| 730 | } else { |
| 731 | /* |
| 732 | * Update the timer in case it has |
| 733 | * overrun already. If it has, |
| 734 | * we'll report it as having overrun |
| 735 | * and with the next reloaded timer |
| 736 | * already ticking, though we are |
| 737 | * swallowing that pending |
| 738 | * notification here to install the |
| 739 | * new setting. |
| 740 | */ |
| 741 | bump_cpu_timer(timer, val); |
| 742 | if (cpu_time_before(timer->it_clock, val, |
| 743 | timer->it.cpu.expires)) { |
| 744 | old_expires = cpu_time_sub( |
| 745 | timer->it_clock, |
| 746 | timer->it.cpu.expires, val); |
| 747 | sample_to_timespec(timer->it_clock, |
| 748 | old_expires, |
| 749 | &old->it_value); |
| 750 | } else { |
| 751 | old->it_value.tv_nsec = 1; |
| 752 | old->it_value.tv_sec = 0; |
| 753 | } |
| 754 | } |
| 755 | } |
| 756 | |
Oleg Nesterov | a69ac4a | 2005-10-24 18:29:58 +0400 | [diff] [blame] | 757 | if (unlikely(ret)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 758 | /* |
| 759 | * We are colliding with the timer actually firing. |
| 760 | * Punt after filling in the timer's old value, and |
| 761 | * disable this firing since we are already reporting |
| 762 | * it as an overrun (thanks to bump_cpu_timer above). |
| 763 | */ |
Stanislaw Gruszka | c287393 | 2010-03-11 14:04:42 -0800 | [diff] [blame] | 764 | spin_unlock(&p->sighand->siglock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 765 | read_unlock(&tasklist_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 766 | goto out; |
| 767 | } |
| 768 | |
| 769 | if (new_expires.sched != 0 && !(flags & TIMER_ABSTIME)) { |
| 770 | cpu_time_add(timer->it_clock, &new_expires, val); |
| 771 | } |
| 772 | |
| 773 | /* |
| 774 | * Install the new expiry time (or zero). |
| 775 | * For a timer with no notification action, we don't actually |
| 776 | * arm the timer (we'll just fake it for timer_gettime). |
| 777 | */ |
| 778 | timer->it.cpu.expires = new_expires; |
| 779 | if (new_expires.sched != 0 && |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 780 | cpu_time_before(timer->it_clock, val, new_expires)) { |
Stanislaw Gruszka | 5eb9aa6 | 2010-03-11 14:04:38 -0800 | [diff] [blame] | 781 | arm_timer(timer); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 782 | } |
| 783 | |
Stanislaw Gruszka | c287393 | 2010-03-11 14:04:42 -0800 | [diff] [blame] | 784 | spin_unlock(&p->sighand->siglock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 785 | read_unlock(&tasklist_lock); |
| 786 | |
| 787 | /* |
| 788 | * Install the new reload setting, and |
| 789 | * set up the signal and overrun bookkeeping. |
| 790 | */ |
| 791 | timer->it.cpu.incr = timespec_to_sample(timer->it_clock, |
| 792 | &new->it_interval); |
| 793 | |
| 794 | /* |
| 795 | * This acts as a modification timestamp for the timer, |
| 796 | * so any automatic reload attempt will punt on seeing |
| 797 | * that we have reset the timer manually. |
| 798 | */ |
| 799 | timer->it_requeue_pending = (timer->it_requeue_pending + 2) & |
| 800 | ~REQUEUE_PENDING; |
| 801 | timer->it_overrun_last = 0; |
| 802 | timer->it_overrun = -1; |
| 803 | |
| 804 | if (new_expires.sched != 0 && |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 805 | !cpu_time_before(timer->it_clock, val, new_expires)) { |
| 806 | /* |
| 807 | * The designated time already passed, so we notify |
| 808 | * immediately, even if the thread never runs to |
| 809 | * accumulate more time on this clock. |
| 810 | */ |
| 811 | cpu_timer_fire(timer); |
| 812 | } |
| 813 | |
| 814 | ret = 0; |
| 815 | out: |
| 816 | if (old) { |
| 817 | sample_to_timespec(timer->it_clock, |
Stanislaw Gruszka | ae1a78e | 2010-03-11 14:04:39 -0800 | [diff] [blame] | 818 | old_incr, &old->it_interval); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 819 | } |
| 820 | return ret; |
| 821 | } |
| 822 | |
| 823 | void posix_cpu_timer_get(struct k_itimer *timer, struct itimerspec *itp) |
| 824 | { |
| 825 | union cpu_time_count now; |
| 826 | struct task_struct *p = timer->it.cpu.task; |
| 827 | int clear_dead; |
| 828 | |
| 829 | /* |
| 830 | * Easy part: convert the reload time. |
| 831 | */ |
| 832 | sample_to_timespec(timer->it_clock, |
| 833 | timer->it.cpu.incr, &itp->it_interval); |
| 834 | |
| 835 | if (timer->it.cpu.expires.sched == 0) { /* Timer not armed at all. */ |
| 836 | itp->it_value.tv_sec = itp->it_value.tv_nsec = 0; |
| 837 | return; |
| 838 | } |
| 839 | |
| 840 | if (unlikely(p == NULL)) { |
| 841 | /* |
| 842 | * This task already died and the timer will never fire. |
| 843 | * In this case, expires is actually the dead value. |
| 844 | */ |
| 845 | dead: |
| 846 | sample_to_timespec(timer->it_clock, timer->it.cpu.expires, |
| 847 | &itp->it_value); |
| 848 | return; |
| 849 | } |
| 850 | |
| 851 | /* |
| 852 | * Sample the clock to take the difference with the expiry time. |
| 853 | */ |
| 854 | if (CPUCLOCK_PERTHREAD(timer->it_clock)) { |
| 855 | cpu_clock_sample(timer->it_clock, p, &now); |
| 856 | clear_dead = p->exit_state; |
| 857 | } else { |
| 858 | read_lock(&tasklist_lock); |
Oleg Nesterov | d30fda3 | 2010-05-26 14:43:13 -0700 | [diff] [blame] | 859 | if (unlikely(p->sighand == NULL)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 860 | /* |
| 861 | * The process has been reaped. |
| 862 | * We can't even collect a sample any more. |
| 863 | * Call the timer disarmed, nothing else to do. |
| 864 | */ |
| 865 | put_task_struct(p); |
| 866 | timer->it.cpu.task = NULL; |
| 867 | timer->it.cpu.expires.sched = 0; |
| 868 | read_unlock(&tasklist_lock); |
| 869 | goto dead; |
| 870 | } else { |
Peter Zijlstra | 3997ad3 | 2009-02-12 15:00:52 +0100 | [diff] [blame] | 871 | cpu_timer_sample_group(timer->it_clock, p, &now); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 872 | clear_dead = (unlikely(p->exit_state) && |
| 873 | thread_group_empty(p)); |
| 874 | } |
| 875 | read_unlock(&tasklist_lock); |
| 876 | } |
| 877 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 878 | if (unlikely(clear_dead)) { |
| 879 | /* |
| 880 | * We've noticed that the thread is dead, but |
| 881 | * not yet reaped. Take this opportunity to |
| 882 | * drop our task ref. |
| 883 | */ |
| 884 | clear_dead_task(timer, now); |
| 885 | goto dead; |
| 886 | } |
| 887 | |
| 888 | if (cpu_time_before(timer->it_clock, now, timer->it.cpu.expires)) { |
| 889 | sample_to_timespec(timer->it_clock, |
| 890 | cpu_time_sub(timer->it_clock, |
| 891 | timer->it.cpu.expires, now), |
| 892 | &itp->it_value); |
| 893 | } else { |
| 894 | /* |
| 895 | * The timer should have expired already, but the firing |
| 896 | * hasn't taken place yet. Say it's just about to expire. |
| 897 | */ |
| 898 | itp->it_value.tv_nsec = 1; |
| 899 | itp->it_value.tv_sec = 0; |
| 900 | } |
| 901 | } |
| 902 | |
| 903 | /* |
| 904 | * Check for any per-thread CPU timers that have fired and move them off |
| 905 | * the tsk->cpu_timers[N] list onto the firing list. Here we update the |
| 906 | * tsk->it_*_expires values to reflect the remaining thread CPU timers. |
| 907 | */ |
| 908 | static void check_thread_timers(struct task_struct *tsk, |
| 909 | struct list_head *firing) |
| 910 | { |
Linus Torvalds | e80eda9 | 2005-10-23 10:02:50 -0700 | [diff] [blame] | 911 | int maxfire; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 912 | struct list_head *timers = tsk->cpu_timers; |
Peter Zijlstra | 78f2c7d | 2008-01-25 21:08:27 +0100 | [diff] [blame] | 913 | struct signal_struct *const sig = tsk->signal; |
Jiri Slaby | d4bb5274 | 2010-03-05 13:42:53 -0800 | [diff] [blame] | 914 | unsigned long soft; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 915 | |
Linus Torvalds | e80eda9 | 2005-10-23 10:02:50 -0700 | [diff] [blame] | 916 | maxfire = 20; |
Frank Mayhar | f06febc | 2008-09-12 09:54:39 -0700 | [diff] [blame] | 917 | tsk->cputime_expires.prof_exp = cputime_zero; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 918 | while (!list_empty(timers)) { |
Pavel Emelianov | b5e6181 | 2007-05-08 00:30:19 -0700 | [diff] [blame] | 919 | struct cpu_timer_list *t = list_first_entry(timers, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 920 | struct cpu_timer_list, |
| 921 | entry); |
Linus Torvalds | e80eda9 | 2005-10-23 10:02:50 -0700 | [diff] [blame] | 922 | if (!--maxfire || cputime_lt(prof_ticks(tsk), t->expires.cpu)) { |
Frank Mayhar | f06febc | 2008-09-12 09:54:39 -0700 | [diff] [blame] | 923 | tsk->cputime_expires.prof_exp = t->expires.cpu; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 924 | break; |
| 925 | } |
| 926 | t->firing = 1; |
| 927 | list_move_tail(&t->entry, firing); |
| 928 | } |
| 929 | |
| 930 | ++timers; |
Linus Torvalds | e80eda9 | 2005-10-23 10:02:50 -0700 | [diff] [blame] | 931 | maxfire = 20; |
Frank Mayhar | f06febc | 2008-09-12 09:54:39 -0700 | [diff] [blame] | 932 | tsk->cputime_expires.virt_exp = cputime_zero; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 933 | while (!list_empty(timers)) { |
Pavel Emelianov | b5e6181 | 2007-05-08 00:30:19 -0700 | [diff] [blame] | 934 | struct cpu_timer_list *t = list_first_entry(timers, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 935 | struct cpu_timer_list, |
| 936 | entry); |
Linus Torvalds | e80eda9 | 2005-10-23 10:02:50 -0700 | [diff] [blame] | 937 | if (!--maxfire || cputime_lt(virt_ticks(tsk), t->expires.cpu)) { |
Frank Mayhar | f06febc | 2008-09-12 09:54:39 -0700 | [diff] [blame] | 938 | tsk->cputime_expires.virt_exp = t->expires.cpu; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 939 | break; |
| 940 | } |
| 941 | t->firing = 1; |
| 942 | list_move_tail(&t->entry, firing); |
| 943 | } |
| 944 | |
| 945 | ++timers; |
Linus Torvalds | e80eda9 | 2005-10-23 10:02:50 -0700 | [diff] [blame] | 946 | maxfire = 20; |
Frank Mayhar | f06febc | 2008-09-12 09:54:39 -0700 | [diff] [blame] | 947 | tsk->cputime_expires.sched_exp = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 948 | while (!list_empty(timers)) { |
Pavel Emelianov | b5e6181 | 2007-05-08 00:30:19 -0700 | [diff] [blame] | 949 | struct cpu_timer_list *t = list_first_entry(timers, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 950 | struct cpu_timer_list, |
| 951 | entry); |
Ingo Molnar | 41b86e9 | 2007-07-09 18:51:58 +0200 | [diff] [blame] | 952 | if (!--maxfire || tsk->se.sum_exec_runtime < t->expires.sched) { |
Frank Mayhar | f06febc | 2008-09-12 09:54:39 -0700 | [diff] [blame] | 953 | tsk->cputime_expires.sched_exp = t->expires.sched; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 954 | break; |
| 955 | } |
| 956 | t->firing = 1; |
| 957 | list_move_tail(&t->entry, firing); |
| 958 | } |
Peter Zijlstra | 78f2c7d | 2008-01-25 21:08:27 +0100 | [diff] [blame] | 959 | |
| 960 | /* |
| 961 | * Check for the special case thread timers. |
| 962 | */ |
Jiri Slaby | 78d7d40 | 2010-03-05 13:42:54 -0800 | [diff] [blame] | 963 | soft = ACCESS_ONCE(sig->rlim[RLIMIT_RTTIME].rlim_cur); |
Jiri Slaby | d4bb5274 | 2010-03-05 13:42:53 -0800 | [diff] [blame] | 964 | if (soft != RLIM_INFINITY) { |
Jiri Slaby | 78d7d40 | 2010-03-05 13:42:54 -0800 | [diff] [blame] | 965 | unsigned long hard = |
| 966 | ACCESS_ONCE(sig->rlim[RLIMIT_RTTIME].rlim_max); |
Peter Zijlstra | 78f2c7d | 2008-01-25 21:08:27 +0100 | [diff] [blame] | 967 | |
Peter Zijlstra | 5a52dd5 | 2008-01-25 21:08:32 +0100 | [diff] [blame] | 968 | if (hard != RLIM_INFINITY && |
| 969 | tsk->rt.timeout > DIV_ROUND_UP(hard, USEC_PER_SEC/HZ)) { |
Peter Zijlstra | 78f2c7d | 2008-01-25 21:08:27 +0100 | [diff] [blame] | 970 | /* |
| 971 | * At the hard limit, we just die. |
| 972 | * No need to calculate anything else now. |
| 973 | */ |
| 974 | __group_send_sig_info(SIGKILL, SEND_SIG_PRIV, tsk); |
| 975 | return; |
| 976 | } |
Jiri Slaby | d4bb5274 | 2010-03-05 13:42:53 -0800 | [diff] [blame] | 977 | if (tsk->rt.timeout > DIV_ROUND_UP(soft, USEC_PER_SEC/HZ)) { |
Peter Zijlstra | 78f2c7d | 2008-01-25 21:08:27 +0100 | [diff] [blame] | 978 | /* |
| 979 | * At the soft limit, send a SIGXCPU every second. |
| 980 | */ |
Jiri Slaby | d4bb5274 | 2010-03-05 13:42:53 -0800 | [diff] [blame] | 981 | if (soft < hard) { |
| 982 | soft += USEC_PER_SEC; |
| 983 | sig->rlim[RLIMIT_RTTIME].rlim_cur = soft; |
Peter Zijlstra | 78f2c7d | 2008-01-25 21:08:27 +0100 | [diff] [blame] | 984 | } |
Hiroshi Shimamoto | 81d50bb | 2008-05-15 19:42:49 -0700 | [diff] [blame] | 985 | printk(KERN_INFO |
| 986 | "RT Watchdog Timeout: %s[%d]\n", |
| 987 | tsk->comm, task_pid_nr(tsk)); |
Peter Zijlstra | 78f2c7d | 2008-01-25 21:08:27 +0100 | [diff] [blame] | 988 | __group_send_sig_info(SIGXCPU, SEND_SIG_PRIV, tsk); |
| 989 | } |
| 990 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 991 | } |
| 992 | |
Stanislaw Gruszka | 15365c1 | 2010-03-11 14:04:31 -0800 | [diff] [blame] | 993 | static void stop_process_timers(struct signal_struct *sig) |
Peter Zijlstra | 3fccfd6 | 2009-02-10 16:37:31 +0100 | [diff] [blame] | 994 | { |
Stanislaw Gruszka | 15365c1 | 2010-03-11 14:04:31 -0800 | [diff] [blame] | 995 | struct thread_group_cputimer *cputimer = &sig->cputimer; |
Peter Zijlstra | 3fccfd6 | 2009-02-10 16:37:31 +0100 | [diff] [blame] | 996 | unsigned long flags; |
| 997 | |
Peter Zijlstra | 3fccfd6 | 2009-02-10 16:37:31 +0100 | [diff] [blame] | 998 | spin_lock_irqsave(&cputimer->lock, flags); |
| 999 | cputimer->running = 0; |
| 1000 | spin_unlock_irqrestore(&cputimer->lock, flags); |
| 1001 | } |
| 1002 | |
Stanislaw Gruszka | 8356b5f | 2009-07-29 12:15:27 +0200 | [diff] [blame] | 1003 | static u32 onecputick; |
| 1004 | |
Stanislaw Gruszka | 42c4ab4 | 2009-07-29 12:15:26 +0200 | [diff] [blame] | 1005 | static void check_cpu_itimer(struct task_struct *tsk, struct cpu_itimer *it, |
| 1006 | cputime_t *expires, cputime_t cur_time, int signo) |
| 1007 | { |
| 1008 | if (cputime_eq(it->expires, cputime_zero)) |
| 1009 | return; |
| 1010 | |
| 1011 | if (cputime_ge(cur_time, it->expires)) { |
Stanislaw Gruszka | 8356b5f | 2009-07-29 12:15:27 +0200 | [diff] [blame] | 1012 | if (!cputime_eq(it->incr, cputime_zero)) { |
| 1013 | it->expires = cputime_add(it->expires, it->incr); |
| 1014 | it->error += it->incr_error; |
| 1015 | if (it->error >= onecputick) { |
| 1016 | it->expires = cputime_sub(it->expires, |
Stanislaw Gruszka | a42548a | 2009-07-29 12:15:29 +0200 | [diff] [blame] | 1017 | cputime_one_jiffy); |
Stanislaw Gruszka | 8356b5f | 2009-07-29 12:15:27 +0200 | [diff] [blame] | 1018 | it->error -= onecputick; |
| 1019 | } |
Xiao Guangrong | 3f0a525 | 2009-08-10 10:52:30 +0800 | [diff] [blame] | 1020 | } else { |
Stanislaw Gruszka | 8356b5f | 2009-07-29 12:15:27 +0200 | [diff] [blame] | 1021 | it->expires = cputime_zero; |
Xiao Guangrong | 3f0a525 | 2009-08-10 10:52:30 +0800 | [diff] [blame] | 1022 | } |
Stanislaw Gruszka | 42c4ab4 | 2009-07-29 12:15:26 +0200 | [diff] [blame] | 1023 | |
Xiao Guangrong | 3f0a525 | 2009-08-10 10:52:30 +0800 | [diff] [blame] | 1024 | trace_itimer_expire(signo == SIGPROF ? |
| 1025 | ITIMER_PROF : ITIMER_VIRTUAL, |
| 1026 | tsk->signal->leader_pid, cur_time); |
Stanislaw Gruszka | 42c4ab4 | 2009-07-29 12:15:26 +0200 | [diff] [blame] | 1027 | __group_send_sig_info(signo, SEND_SIG_PRIV, tsk); |
| 1028 | } |
| 1029 | |
| 1030 | if (!cputime_eq(it->expires, cputime_zero) && |
| 1031 | (cputime_eq(*expires, cputime_zero) || |
| 1032 | cputime_lt(it->expires, *expires))) { |
| 1033 | *expires = it->expires; |
| 1034 | } |
| 1035 | } |
| 1036 | |
Stanislaw Gruszka | 29f87b7 | 2010-04-27 14:12:15 -0700 | [diff] [blame] | 1037 | /** |
| 1038 | * task_cputime_zero - Check a task_cputime struct for all zero fields. |
| 1039 | * |
| 1040 | * @cputime: The struct to compare. |
| 1041 | * |
| 1042 | * Checks @cputime to see if all fields are zero. Returns true if all fields |
| 1043 | * are zero, false if any field is nonzero. |
| 1044 | */ |
| 1045 | static inline int task_cputime_zero(const struct task_cputime *cputime) |
| 1046 | { |
| 1047 | if (cputime_eq(cputime->utime, cputime_zero) && |
| 1048 | cputime_eq(cputime->stime, cputime_zero) && |
| 1049 | cputime->sum_exec_runtime == 0) |
| 1050 | return 1; |
| 1051 | return 0; |
| 1052 | } |
| 1053 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1054 | /* |
| 1055 | * Check for any per-thread CPU timers that have fired and move them |
| 1056 | * off the tsk->*_timers list onto the firing list. Per-thread timers |
| 1057 | * have already been taken off. |
| 1058 | */ |
| 1059 | static void check_process_timers(struct task_struct *tsk, |
| 1060 | struct list_head *firing) |
| 1061 | { |
Linus Torvalds | e80eda9 | 2005-10-23 10:02:50 -0700 | [diff] [blame] | 1062 | int maxfire; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1063 | struct signal_struct *const sig = tsk->signal; |
Frank Mayhar | f06febc | 2008-09-12 09:54:39 -0700 | [diff] [blame] | 1064 | cputime_t utime, ptime, virt_expires, prof_expires; |
Ingo Molnar | 41b86e9 | 2007-07-09 18:51:58 +0200 | [diff] [blame] | 1065 | unsigned long long sum_sched_runtime, sched_expires; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1066 | struct list_head *timers = sig->cpu_timers; |
Frank Mayhar | f06febc | 2008-09-12 09:54:39 -0700 | [diff] [blame] | 1067 | struct task_cputime cputime; |
Jiri Slaby | d4bb5274 | 2010-03-05 13:42:53 -0800 | [diff] [blame] | 1068 | unsigned long soft; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1069 | |
| 1070 | /* |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1071 | * Collect the current process totals. |
| 1072 | */ |
Peter Zijlstra | 4cd4c1b | 2009-02-05 12:24:16 +0100 | [diff] [blame] | 1073 | thread_group_cputimer(tsk, &cputime); |
Frank Mayhar | f06febc | 2008-09-12 09:54:39 -0700 | [diff] [blame] | 1074 | utime = cputime.utime; |
| 1075 | ptime = cputime_add(utime, cputime.stime); |
| 1076 | sum_sched_runtime = cputime.sum_exec_runtime; |
Linus Torvalds | e80eda9 | 2005-10-23 10:02:50 -0700 | [diff] [blame] | 1077 | maxfire = 20; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1078 | prof_expires = cputime_zero; |
| 1079 | while (!list_empty(timers)) { |
WANG Cong | ee7dd20 | 2008-04-04 20:54:10 +0200 | [diff] [blame] | 1080 | struct cpu_timer_list *tl = list_first_entry(timers, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1081 | struct cpu_timer_list, |
| 1082 | entry); |
WANG Cong | ee7dd20 | 2008-04-04 20:54:10 +0200 | [diff] [blame] | 1083 | if (!--maxfire || cputime_lt(ptime, tl->expires.cpu)) { |
| 1084 | prof_expires = tl->expires.cpu; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1085 | break; |
| 1086 | } |
WANG Cong | ee7dd20 | 2008-04-04 20:54:10 +0200 | [diff] [blame] | 1087 | tl->firing = 1; |
| 1088 | list_move_tail(&tl->entry, firing); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1089 | } |
| 1090 | |
| 1091 | ++timers; |
Linus Torvalds | e80eda9 | 2005-10-23 10:02:50 -0700 | [diff] [blame] | 1092 | maxfire = 20; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1093 | virt_expires = cputime_zero; |
| 1094 | while (!list_empty(timers)) { |
WANG Cong | ee7dd20 | 2008-04-04 20:54:10 +0200 | [diff] [blame] | 1095 | struct cpu_timer_list *tl = list_first_entry(timers, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1096 | struct cpu_timer_list, |
| 1097 | entry); |
WANG Cong | ee7dd20 | 2008-04-04 20:54:10 +0200 | [diff] [blame] | 1098 | if (!--maxfire || cputime_lt(utime, tl->expires.cpu)) { |
| 1099 | virt_expires = tl->expires.cpu; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1100 | break; |
| 1101 | } |
WANG Cong | ee7dd20 | 2008-04-04 20:54:10 +0200 | [diff] [blame] | 1102 | tl->firing = 1; |
| 1103 | list_move_tail(&tl->entry, firing); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1104 | } |
| 1105 | |
| 1106 | ++timers; |
Linus Torvalds | e80eda9 | 2005-10-23 10:02:50 -0700 | [diff] [blame] | 1107 | maxfire = 20; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1108 | sched_expires = 0; |
| 1109 | while (!list_empty(timers)) { |
WANG Cong | ee7dd20 | 2008-04-04 20:54:10 +0200 | [diff] [blame] | 1110 | struct cpu_timer_list *tl = list_first_entry(timers, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1111 | struct cpu_timer_list, |
| 1112 | entry); |
WANG Cong | ee7dd20 | 2008-04-04 20:54:10 +0200 | [diff] [blame] | 1113 | if (!--maxfire || sum_sched_runtime < tl->expires.sched) { |
| 1114 | sched_expires = tl->expires.sched; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1115 | break; |
| 1116 | } |
WANG Cong | ee7dd20 | 2008-04-04 20:54:10 +0200 | [diff] [blame] | 1117 | tl->firing = 1; |
| 1118 | list_move_tail(&tl->entry, firing); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1119 | } |
| 1120 | |
| 1121 | /* |
| 1122 | * Check for the special case process timers. |
| 1123 | */ |
Stanislaw Gruszka | 42c4ab4 | 2009-07-29 12:15:26 +0200 | [diff] [blame] | 1124 | check_cpu_itimer(tsk, &sig->it[CPUCLOCK_PROF], &prof_expires, ptime, |
| 1125 | SIGPROF); |
| 1126 | check_cpu_itimer(tsk, &sig->it[CPUCLOCK_VIRT], &virt_expires, utime, |
| 1127 | SIGVTALRM); |
Jiri Slaby | 78d7d40 | 2010-03-05 13:42:54 -0800 | [diff] [blame] | 1128 | soft = ACCESS_ONCE(sig->rlim[RLIMIT_CPU].rlim_cur); |
Jiri Slaby | d4bb5274 | 2010-03-05 13:42:53 -0800 | [diff] [blame] | 1129 | if (soft != RLIM_INFINITY) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1130 | unsigned long psecs = cputime_to_secs(ptime); |
Jiri Slaby | 78d7d40 | 2010-03-05 13:42:54 -0800 | [diff] [blame] | 1131 | unsigned long hard = |
| 1132 | ACCESS_ONCE(sig->rlim[RLIMIT_CPU].rlim_max); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1133 | cputime_t x; |
Jiri Slaby | d4bb5274 | 2010-03-05 13:42:53 -0800 | [diff] [blame] | 1134 | if (psecs >= hard) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1135 | /* |
| 1136 | * At the hard limit, we just die. |
| 1137 | * No need to calculate anything else now. |
| 1138 | */ |
| 1139 | __group_send_sig_info(SIGKILL, SEND_SIG_PRIV, tsk); |
| 1140 | return; |
| 1141 | } |
Jiri Slaby | d4bb5274 | 2010-03-05 13:42:53 -0800 | [diff] [blame] | 1142 | if (psecs >= soft) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1143 | /* |
| 1144 | * At the soft limit, send a SIGXCPU every second. |
| 1145 | */ |
| 1146 | __group_send_sig_info(SIGXCPU, SEND_SIG_PRIV, tsk); |
Jiri Slaby | d4bb5274 | 2010-03-05 13:42:53 -0800 | [diff] [blame] | 1147 | if (soft < hard) { |
| 1148 | soft++; |
| 1149 | sig->rlim[RLIMIT_CPU].rlim_cur = soft; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1150 | } |
| 1151 | } |
Jiri Slaby | d4bb5274 | 2010-03-05 13:42:53 -0800 | [diff] [blame] | 1152 | x = secs_to_cputime(soft); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1153 | if (cputime_eq(prof_expires, cputime_zero) || |
| 1154 | cputime_lt(x, prof_expires)) { |
| 1155 | prof_expires = x; |
| 1156 | } |
| 1157 | } |
| 1158 | |
Stanislaw Gruszka | 29f87b7 | 2010-04-27 14:12:15 -0700 | [diff] [blame] | 1159 | sig->cputime_expires.prof_exp = prof_expires; |
| 1160 | sig->cputime_expires.virt_exp = virt_expires; |
| 1161 | sig->cputime_expires.sched_exp = sched_expires; |
| 1162 | if (task_cputime_zero(&sig->cputime_expires)) |
| 1163 | stop_process_timers(sig); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1164 | } |
| 1165 | |
| 1166 | /* |
| 1167 | * This is called from the signal code (via do_schedule_next_timer) |
| 1168 | * when the last timer signal was delivered and we have to reload the timer. |
| 1169 | */ |
| 1170 | void posix_cpu_timer_schedule(struct k_itimer *timer) |
| 1171 | { |
| 1172 | struct task_struct *p = timer->it.cpu.task; |
| 1173 | union cpu_time_count now; |
| 1174 | |
| 1175 | if (unlikely(p == NULL)) |
| 1176 | /* |
| 1177 | * The task was cleaned up already, no future firings. |
| 1178 | */ |
Roland McGrath | 708f430 | 2005-10-30 15:03:13 -0800 | [diff] [blame] | 1179 | goto out; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1180 | |
| 1181 | /* |
| 1182 | * Fetch the current sample and update the timer's expiry time. |
| 1183 | */ |
| 1184 | if (CPUCLOCK_PERTHREAD(timer->it_clock)) { |
| 1185 | cpu_clock_sample(timer->it_clock, p, &now); |
| 1186 | bump_cpu_timer(timer, now); |
| 1187 | if (unlikely(p->exit_state)) { |
| 1188 | clear_dead_task(timer, now); |
Roland McGrath | 708f430 | 2005-10-30 15:03:13 -0800 | [diff] [blame] | 1189 | goto out; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1190 | } |
| 1191 | read_lock(&tasklist_lock); /* arm_timer needs it. */ |
Stanislaw Gruszka | c287393 | 2010-03-11 14:04:42 -0800 | [diff] [blame] | 1192 | spin_lock(&p->sighand->siglock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1193 | } else { |
| 1194 | read_lock(&tasklist_lock); |
Oleg Nesterov | d30fda3 | 2010-05-26 14:43:13 -0700 | [diff] [blame] | 1195 | if (unlikely(p->sighand == NULL)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1196 | /* |
| 1197 | * The process has been reaped. |
| 1198 | * We can't even collect a sample any more. |
| 1199 | */ |
| 1200 | put_task_struct(p); |
| 1201 | timer->it.cpu.task = p = NULL; |
| 1202 | timer->it.cpu.expires.sched = 0; |
Roland McGrath | 708f430 | 2005-10-30 15:03:13 -0800 | [diff] [blame] | 1203 | goto out_unlock; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1204 | } else if (unlikely(p->exit_state) && thread_group_empty(p)) { |
| 1205 | /* |
| 1206 | * We've noticed that the thread is dead, but |
| 1207 | * not yet reaped. Take this opportunity to |
| 1208 | * drop our task ref. |
| 1209 | */ |
| 1210 | clear_dead_task(timer, now); |
Roland McGrath | 708f430 | 2005-10-30 15:03:13 -0800 | [diff] [blame] | 1211 | goto out_unlock; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1212 | } |
Stanislaw Gruszka | c287393 | 2010-03-11 14:04:42 -0800 | [diff] [blame] | 1213 | spin_lock(&p->sighand->siglock); |
Peter Zijlstra | 3997ad3 | 2009-02-12 15:00:52 +0100 | [diff] [blame] | 1214 | cpu_timer_sample_group(timer->it_clock, p, &now); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1215 | bump_cpu_timer(timer, now); |
| 1216 | /* Leave the tasklist_lock locked for the call below. */ |
| 1217 | } |
| 1218 | |
| 1219 | /* |
| 1220 | * Now re-arm for the new expiry time. |
| 1221 | */ |
Stanislaw Gruszka | c287393 | 2010-03-11 14:04:42 -0800 | [diff] [blame] | 1222 | BUG_ON(!irqs_disabled()); |
Stanislaw Gruszka | 5eb9aa6 | 2010-03-11 14:04:38 -0800 | [diff] [blame] | 1223 | arm_timer(timer); |
Stanislaw Gruszka | c287393 | 2010-03-11 14:04:42 -0800 | [diff] [blame] | 1224 | spin_unlock(&p->sighand->siglock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1225 | |
Roland McGrath | 708f430 | 2005-10-30 15:03:13 -0800 | [diff] [blame] | 1226 | out_unlock: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1227 | read_unlock(&tasklist_lock); |
Roland McGrath | 708f430 | 2005-10-30 15:03:13 -0800 | [diff] [blame] | 1228 | |
| 1229 | out: |
| 1230 | timer->it_overrun_last = timer->it_overrun; |
| 1231 | timer->it_overrun = -1; |
| 1232 | ++timer->it_requeue_pending; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1233 | } |
| 1234 | |
Frank Mayhar | f06febc | 2008-09-12 09:54:39 -0700 | [diff] [blame] | 1235 | /** |
Frank Mayhar | f06febc | 2008-09-12 09:54:39 -0700 | [diff] [blame] | 1236 | * task_cputime_expired - Compare two task_cputime entities. |
| 1237 | * |
| 1238 | * @sample: The task_cputime structure to be checked for expiration. |
| 1239 | * @expires: Expiration times, against which @sample will be checked. |
| 1240 | * |
| 1241 | * Checks @sample against @expires to see if any field of @sample has expired. |
| 1242 | * Returns true if any field of the former is greater than the corresponding |
| 1243 | * field of the latter if the latter field is set. Otherwise returns false. |
| 1244 | */ |
| 1245 | static inline int task_cputime_expired(const struct task_cputime *sample, |
| 1246 | const struct task_cputime *expires) |
| 1247 | { |
| 1248 | if (!cputime_eq(expires->utime, cputime_zero) && |
| 1249 | cputime_ge(sample->utime, expires->utime)) |
| 1250 | return 1; |
| 1251 | if (!cputime_eq(expires->stime, cputime_zero) && |
| 1252 | cputime_ge(cputime_add(sample->utime, sample->stime), |
| 1253 | expires->stime)) |
| 1254 | return 1; |
| 1255 | if (expires->sum_exec_runtime != 0 && |
| 1256 | sample->sum_exec_runtime >= expires->sum_exec_runtime) |
| 1257 | return 1; |
| 1258 | return 0; |
| 1259 | } |
| 1260 | |
| 1261 | /** |
| 1262 | * fastpath_timer_check - POSIX CPU timers fast path. |
| 1263 | * |
| 1264 | * @tsk: The task (thread) being checked. |
Frank Mayhar | f06febc | 2008-09-12 09:54:39 -0700 | [diff] [blame] | 1265 | * |
Frank Mayhar | bb34d92 | 2008-09-12 09:54:39 -0700 | [diff] [blame] | 1266 | * Check the task and thread group timers. If both are zero (there are no |
| 1267 | * timers set) return false. Otherwise snapshot the task and thread group |
| 1268 | * timers and compare them with the corresponding expiration times. Return |
| 1269 | * true if a timer has expired, else return false. |
Frank Mayhar | f06febc | 2008-09-12 09:54:39 -0700 | [diff] [blame] | 1270 | */ |
Frank Mayhar | bb34d92 | 2008-09-12 09:54:39 -0700 | [diff] [blame] | 1271 | static inline int fastpath_timer_check(struct task_struct *tsk) |
Frank Mayhar | f06febc | 2008-09-12 09:54:39 -0700 | [diff] [blame] | 1272 | { |
Oleg Nesterov | ad133ba | 2008-11-17 15:39:47 +0100 | [diff] [blame] | 1273 | struct signal_struct *sig; |
Frank Mayhar | f06febc | 2008-09-12 09:54:39 -0700 | [diff] [blame] | 1274 | |
Frank Mayhar | bb34d92 | 2008-09-12 09:54:39 -0700 | [diff] [blame] | 1275 | if (!task_cputime_zero(&tsk->cputime_expires)) { |
| 1276 | struct task_cputime task_sample = { |
| 1277 | .utime = tsk->utime, |
| 1278 | .stime = tsk->stime, |
| 1279 | .sum_exec_runtime = tsk->se.sum_exec_runtime |
| 1280 | }; |
| 1281 | |
| 1282 | if (task_cputime_expired(&task_sample, &tsk->cputime_expires)) |
| 1283 | return 1; |
| 1284 | } |
Oleg Nesterov | ad133ba | 2008-11-17 15:39:47 +0100 | [diff] [blame] | 1285 | |
| 1286 | sig = tsk->signal; |
Stanislaw Gruszka | 29f87b7 | 2010-04-27 14:12:15 -0700 | [diff] [blame] | 1287 | if (sig->cputimer.running) { |
Frank Mayhar | bb34d92 | 2008-09-12 09:54:39 -0700 | [diff] [blame] | 1288 | struct task_cputime group_sample; |
| 1289 | |
Oleg Nesterov | 8d1f431 | 2010-06-11 20:04:46 +0200 | [diff] [blame] | 1290 | spin_lock(&sig->cputimer.lock); |
| 1291 | group_sample = sig->cputimer.cputime; |
| 1292 | spin_unlock(&sig->cputimer.lock); |
| 1293 | |
Frank Mayhar | bb34d92 | 2008-09-12 09:54:39 -0700 | [diff] [blame] | 1294 | if (task_cputime_expired(&group_sample, &sig->cputime_expires)) |
| 1295 | return 1; |
| 1296 | } |
Oleg Nesterov | 37bebc7 | 2009-03-23 20:34:11 +0100 | [diff] [blame] | 1297 | |
Stanislaw Gruszka | f55db60 | 2010-03-11 14:04:37 -0800 | [diff] [blame] | 1298 | return 0; |
Frank Mayhar | f06febc | 2008-09-12 09:54:39 -0700 | [diff] [blame] | 1299 | } |
| 1300 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1301 | /* |
| 1302 | * This is called from the timer interrupt handler. The irq handler has |
| 1303 | * already updated our counts. We need to check if any timers fire now. |
| 1304 | * Interrupts are disabled. |
| 1305 | */ |
| 1306 | void run_posix_cpu_timers(struct task_struct *tsk) |
| 1307 | { |
| 1308 | LIST_HEAD(firing); |
| 1309 | struct k_itimer *timer, *next; |
Oleg Nesterov | 0bdd2ed | 2010-06-11 01:10:18 +0200 | [diff] [blame] | 1310 | unsigned long flags; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1311 | |
| 1312 | BUG_ON(!irqs_disabled()); |
| 1313 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1314 | /* |
Frank Mayhar | f06febc | 2008-09-12 09:54:39 -0700 | [diff] [blame] | 1315 | * The fast path checks that there are no expired thread or thread |
Frank Mayhar | bb34d92 | 2008-09-12 09:54:39 -0700 | [diff] [blame] | 1316 | * group timers. If that's so, just return. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1317 | */ |
Frank Mayhar | bb34d92 | 2008-09-12 09:54:39 -0700 | [diff] [blame] | 1318 | if (!fastpath_timer_check(tsk)) |
Frank Mayhar | f06febc | 2008-09-12 09:54:39 -0700 | [diff] [blame] | 1319 | return; |
Ingo Molnar | 5ce73a4 | 2008-09-14 17:11:46 +0200 | [diff] [blame] | 1320 | |
Oleg Nesterov | 0bdd2ed | 2010-06-11 01:10:18 +0200 | [diff] [blame] | 1321 | if (!lock_task_sighand(tsk, &flags)) |
| 1322 | return; |
Frank Mayhar | bb34d92 | 2008-09-12 09:54:39 -0700 | [diff] [blame] | 1323 | /* |
| 1324 | * Here we take off tsk->signal->cpu_timers[N] and |
| 1325 | * tsk->cpu_timers[N] all the timers that are firing, and |
| 1326 | * put them on the firing list. |
| 1327 | */ |
| 1328 | check_thread_timers(tsk, &firing); |
Stanislaw Gruszka | 29f87b7 | 2010-04-27 14:12:15 -0700 | [diff] [blame] | 1329 | /* |
| 1330 | * If there are any active process wide timers (POSIX 1.b, itimers, |
| 1331 | * RLIMIT_CPU) cputimer must be running. |
| 1332 | */ |
| 1333 | if (tsk->signal->cputimer.running) |
| 1334 | check_process_timers(tsk, &firing); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1335 | |
Frank Mayhar | bb34d92 | 2008-09-12 09:54:39 -0700 | [diff] [blame] | 1336 | /* |
| 1337 | * We must release these locks before taking any timer's lock. |
| 1338 | * There is a potential race with timer deletion here, as the |
| 1339 | * siglock now protects our private firing list. We have set |
| 1340 | * the firing flag in each timer, so that a deletion attempt |
| 1341 | * that gets the timer lock before we do will give it up and |
| 1342 | * spin until we've taken care of that timer below. |
| 1343 | */ |
Oleg Nesterov | 0bdd2ed | 2010-06-11 01:10:18 +0200 | [diff] [blame] | 1344 | unlock_task_sighand(tsk, &flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1345 | |
| 1346 | /* |
| 1347 | * Now that all the timers on our list have the firing flag, |
| 1348 | * noone will touch their list entries but us. We'll take |
| 1349 | * each timer's lock before clearing its firing flag, so no |
| 1350 | * timer call will interfere. |
| 1351 | */ |
| 1352 | list_for_each_entry_safe(timer, next, &firing, it.cpu.entry) { |
H Hartley Sweeten | 6e85c5b | 2009-04-29 19:14:32 -0400 | [diff] [blame] | 1353 | int cpu_firing; |
| 1354 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1355 | spin_lock(&timer->it_lock); |
| 1356 | list_del_init(&timer->it.cpu.entry); |
H Hartley Sweeten | 6e85c5b | 2009-04-29 19:14:32 -0400 | [diff] [blame] | 1357 | cpu_firing = timer->it.cpu.firing; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1358 | timer->it.cpu.firing = 0; |
| 1359 | /* |
| 1360 | * The firing flag is -1 if we collided with a reset |
| 1361 | * of the timer, which already reported this |
| 1362 | * almost-firing as an overrun. So don't generate an event. |
| 1363 | */ |
H Hartley Sweeten | 6e85c5b | 2009-04-29 19:14:32 -0400 | [diff] [blame] | 1364 | if (likely(cpu_firing >= 0)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1365 | cpu_timer_fire(timer); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1366 | spin_unlock(&timer->it_lock); |
| 1367 | } |
| 1368 | } |
| 1369 | |
| 1370 | /* |
Stanislaw Gruszka | f55db60 | 2010-03-11 14:04:37 -0800 | [diff] [blame] | 1371 | * Set one of the process-wide special case CPU timers or RLIMIT_CPU. |
Frank Mayhar | f06febc | 2008-09-12 09:54:39 -0700 | [diff] [blame] | 1372 | * The tsk->sighand->siglock must be held by the caller. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1373 | */ |
| 1374 | void set_process_cpu_timer(struct task_struct *tsk, unsigned int clock_idx, |
| 1375 | cputime_t *newval, cputime_t *oldval) |
| 1376 | { |
| 1377 | union cpu_time_count now; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1378 | |
| 1379 | BUG_ON(clock_idx == CPUCLOCK_SCHED); |
Peter Zijlstra | 4cd4c1b | 2009-02-05 12:24:16 +0100 | [diff] [blame] | 1380 | cpu_timer_sample_group(clock_idx, tsk, &now); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1381 | |
| 1382 | if (oldval) { |
Stanislaw Gruszka | f55db60 | 2010-03-11 14:04:37 -0800 | [diff] [blame] | 1383 | /* |
| 1384 | * We are setting itimer. The *oldval is absolute and we update |
| 1385 | * it to be relative, *newval argument is relative and we update |
| 1386 | * it to be absolute. |
| 1387 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1388 | if (!cputime_eq(*oldval, cputime_zero)) { |
| 1389 | if (cputime_le(*oldval, now.cpu)) { |
| 1390 | /* Just about to fire. */ |
Stanislaw Gruszka | a42548a | 2009-07-29 12:15:29 +0200 | [diff] [blame] | 1391 | *oldval = cputime_one_jiffy; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1392 | } else { |
| 1393 | *oldval = cputime_sub(*oldval, now.cpu); |
| 1394 | } |
| 1395 | } |
| 1396 | |
| 1397 | if (cputime_eq(*newval, cputime_zero)) |
| 1398 | return; |
| 1399 | *newval = cputime_add(*newval, now.cpu); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1400 | } |
| 1401 | |
| 1402 | /* |
Stanislaw Gruszka | f55db60 | 2010-03-11 14:04:37 -0800 | [diff] [blame] | 1403 | * Update expiration cache if we are the earliest timer, or eventually |
| 1404 | * RLIMIT_CPU limit is earlier than prof_exp cpu timer expire. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1405 | */ |
Stanislaw Gruszka | f55db60 | 2010-03-11 14:04:37 -0800 | [diff] [blame] | 1406 | switch (clock_idx) { |
| 1407 | case CPUCLOCK_PROF: |
| 1408 | if (expires_gt(tsk->signal->cputime_expires.prof_exp, *newval)) |
Frank Mayhar | f06febc | 2008-09-12 09:54:39 -0700 | [diff] [blame] | 1409 | tsk->signal->cputime_expires.prof_exp = *newval; |
Stanislaw Gruszka | f55db60 | 2010-03-11 14:04:37 -0800 | [diff] [blame] | 1410 | break; |
| 1411 | case CPUCLOCK_VIRT: |
| 1412 | if (expires_gt(tsk->signal->cputime_expires.virt_exp, *newval)) |
Frank Mayhar | f06febc | 2008-09-12 09:54:39 -0700 | [diff] [blame] | 1413 | tsk->signal->cputime_expires.virt_exp = *newval; |
Stanislaw Gruszka | f55db60 | 2010-03-11 14:04:37 -0800 | [diff] [blame] | 1414 | break; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1415 | } |
| 1416 | } |
| 1417 | |
Toyo Abe | e4b7655 | 2006-09-29 02:00:29 -0700 | [diff] [blame] | 1418 | static int do_cpu_nanosleep(const clockid_t which_clock, int flags, |
| 1419 | struct timespec *rqtp, struct itimerspec *it) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1420 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1421 | struct k_itimer timer; |
| 1422 | int error; |
| 1423 | |
| 1424 | /* |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1425 | * Set up a temporary timer and then wait for it to go off. |
| 1426 | */ |
| 1427 | memset(&timer, 0, sizeof timer); |
| 1428 | spin_lock_init(&timer.it_lock); |
| 1429 | timer.it_clock = which_clock; |
| 1430 | timer.it_overrun = -1; |
| 1431 | error = posix_cpu_timer_create(&timer); |
| 1432 | timer.it_process = current; |
| 1433 | if (!error) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1434 | static struct itimerspec zero_it; |
Toyo Abe | e4b7655 | 2006-09-29 02:00:29 -0700 | [diff] [blame] | 1435 | |
| 1436 | memset(it, 0, sizeof *it); |
| 1437 | it->it_value = *rqtp; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1438 | |
| 1439 | spin_lock_irq(&timer.it_lock); |
Toyo Abe | e4b7655 | 2006-09-29 02:00:29 -0700 | [diff] [blame] | 1440 | error = posix_cpu_timer_set(&timer, flags, it, NULL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1441 | if (error) { |
| 1442 | spin_unlock_irq(&timer.it_lock); |
| 1443 | return error; |
| 1444 | } |
| 1445 | |
| 1446 | while (!signal_pending(current)) { |
| 1447 | if (timer.it.cpu.expires.sched == 0) { |
| 1448 | /* |
| 1449 | * Our timer fired and was reset. |
| 1450 | */ |
| 1451 | spin_unlock_irq(&timer.it_lock); |
| 1452 | return 0; |
| 1453 | } |
| 1454 | |
| 1455 | /* |
| 1456 | * Block until cpu_timer_fire (or a signal) wakes us. |
| 1457 | */ |
| 1458 | __set_current_state(TASK_INTERRUPTIBLE); |
| 1459 | spin_unlock_irq(&timer.it_lock); |
| 1460 | schedule(); |
| 1461 | spin_lock_irq(&timer.it_lock); |
| 1462 | } |
| 1463 | |
| 1464 | /* |
| 1465 | * We were interrupted by a signal. |
| 1466 | */ |
| 1467 | sample_to_timespec(which_clock, timer.it.cpu.expires, rqtp); |
Toyo Abe | e4b7655 | 2006-09-29 02:00:29 -0700 | [diff] [blame] | 1468 | posix_cpu_timer_set(&timer, 0, &zero_it, it); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1469 | spin_unlock_irq(&timer.it_lock); |
| 1470 | |
Toyo Abe | e4b7655 | 2006-09-29 02:00:29 -0700 | [diff] [blame] | 1471 | if ((it->it_value.tv_sec | it->it_value.tv_nsec) == 0) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1472 | /* |
| 1473 | * It actually did fire already. |
| 1474 | */ |
| 1475 | return 0; |
| 1476 | } |
| 1477 | |
Toyo Abe | e4b7655 | 2006-09-29 02:00:29 -0700 | [diff] [blame] | 1478 | error = -ERESTART_RESTARTBLOCK; |
| 1479 | } |
| 1480 | |
| 1481 | return error; |
| 1482 | } |
| 1483 | |
| 1484 | int posix_cpu_nsleep(const clockid_t which_clock, int flags, |
| 1485 | struct timespec *rqtp, struct timespec __user *rmtp) |
| 1486 | { |
| 1487 | struct restart_block *restart_block = |
| 1488 | ¤t_thread_info()->restart_block; |
| 1489 | struct itimerspec it; |
| 1490 | int error; |
| 1491 | |
| 1492 | /* |
| 1493 | * Diagnose required errors first. |
| 1494 | */ |
| 1495 | if (CPUCLOCK_PERTHREAD(which_clock) && |
| 1496 | (CPUCLOCK_PID(which_clock) == 0 || |
| 1497 | CPUCLOCK_PID(which_clock) == current->pid)) |
| 1498 | return -EINVAL; |
| 1499 | |
| 1500 | error = do_cpu_nanosleep(which_clock, flags, rqtp, &it); |
| 1501 | |
| 1502 | if (error == -ERESTART_RESTARTBLOCK) { |
| 1503 | |
| 1504 | if (flags & TIMER_ABSTIME) |
| 1505 | return -ERESTARTNOHAND; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1506 | /* |
Toyo Abe | e4b7655 | 2006-09-29 02:00:29 -0700 | [diff] [blame] | 1507 | * Report back to the user the time still remaining. |
| 1508 | */ |
| 1509 | if (rmtp != NULL && copy_to_user(rmtp, &it.it_value, sizeof *rmtp)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1510 | return -EFAULT; |
| 1511 | |
Toyo Abe | 1711ef3 | 2006-09-29 02:00:28 -0700 | [diff] [blame] | 1512 | restart_block->fn = posix_cpu_nsleep_restart; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1513 | restart_block->arg0 = which_clock; |
Thomas Gleixner | 97735f2 | 2006-01-09 20:52:37 -0800 | [diff] [blame] | 1514 | restart_block->arg1 = (unsigned long) rmtp; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1515 | restart_block->arg2 = rqtp->tv_sec; |
| 1516 | restart_block->arg3 = rqtp->tv_nsec; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1517 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1518 | return error; |
| 1519 | } |
| 1520 | |
Toyo Abe | 1711ef3 | 2006-09-29 02:00:28 -0700 | [diff] [blame] | 1521 | long posix_cpu_nsleep_restart(struct restart_block *restart_block) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1522 | { |
| 1523 | clockid_t which_clock = restart_block->arg0; |
Thomas Gleixner | 97735f2 | 2006-01-09 20:52:37 -0800 | [diff] [blame] | 1524 | struct timespec __user *rmtp; |
| 1525 | struct timespec t; |
Toyo Abe | e4b7655 | 2006-09-29 02:00:29 -0700 | [diff] [blame] | 1526 | struct itimerspec it; |
| 1527 | int error; |
Thomas Gleixner | 97735f2 | 2006-01-09 20:52:37 -0800 | [diff] [blame] | 1528 | |
| 1529 | rmtp = (struct timespec __user *) restart_block->arg1; |
| 1530 | t.tv_sec = restart_block->arg2; |
| 1531 | t.tv_nsec = restart_block->arg3; |
| 1532 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1533 | restart_block->fn = do_no_restart_syscall; |
Toyo Abe | e4b7655 | 2006-09-29 02:00:29 -0700 | [diff] [blame] | 1534 | error = do_cpu_nanosleep(which_clock, TIMER_ABSTIME, &t, &it); |
| 1535 | |
| 1536 | if (error == -ERESTART_RESTARTBLOCK) { |
| 1537 | /* |
| 1538 | * Report back to the user the time still remaining. |
| 1539 | */ |
| 1540 | if (rmtp != NULL && copy_to_user(rmtp, &it.it_value, sizeof *rmtp)) |
| 1541 | return -EFAULT; |
| 1542 | |
| 1543 | restart_block->fn = posix_cpu_nsleep_restart; |
| 1544 | restart_block->arg0 = which_clock; |
| 1545 | restart_block->arg1 = (unsigned long) rmtp; |
| 1546 | restart_block->arg2 = t.tv_sec; |
| 1547 | restart_block->arg3 = t.tv_nsec; |
| 1548 | } |
| 1549 | return error; |
| 1550 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1551 | } |
| 1552 | |
| 1553 | |
| 1554 | #define PROCESS_CLOCK MAKE_PROCESS_CPUCLOCK(0, CPUCLOCK_SCHED) |
| 1555 | #define THREAD_CLOCK MAKE_THREAD_CPUCLOCK(0, CPUCLOCK_SCHED) |
| 1556 | |
Thomas Gleixner | a924b04 | 2006-01-09 20:52:27 -0800 | [diff] [blame] | 1557 | static int process_cpu_clock_getres(const clockid_t which_clock, |
| 1558 | struct timespec *tp) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1559 | { |
| 1560 | return posix_cpu_clock_getres(PROCESS_CLOCK, tp); |
| 1561 | } |
Thomas Gleixner | a924b04 | 2006-01-09 20:52:27 -0800 | [diff] [blame] | 1562 | static int process_cpu_clock_get(const clockid_t which_clock, |
| 1563 | struct timespec *tp) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1564 | { |
| 1565 | return posix_cpu_clock_get(PROCESS_CLOCK, tp); |
| 1566 | } |
| 1567 | static int process_cpu_timer_create(struct k_itimer *timer) |
| 1568 | { |
| 1569 | timer->it_clock = PROCESS_CLOCK; |
| 1570 | return posix_cpu_timer_create(timer); |
| 1571 | } |
Thomas Gleixner | a924b04 | 2006-01-09 20:52:27 -0800 | [diff] [blame] | 1572 | static int process_cpu_nsleep(const clockid_t which_clock, int flags, |
Thomas Gleixner | 97735f2 | 2006-01-09 20:52:37 -0800 | [diff] [blame] | 1573 | struct timespec *rqtp, |
| 1574 | struct timespec __user *rmtp) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1575 | { |
Thomas Gleixner | 97735f2 | 2006-01-09 20:52:37 -0800 | [diff] [blame] | 1576 | return posix_cpu_nsleep(PROCESS_CLOCK, flags, rqtp, rmtp); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1577 | } |
Toyo Abe | 1711ef3 | 2006-09-29 02:00:28 -0700 | [diff] [blame] | 1578 | static long process_cpu_nsleep_restart(struct restart_block *restart_block) |
| 1579 | { |
| 1580 | return -EINVAL; |
| 1581 | } |
Thomas Gleixner | a924b04 | 2006-01-09 20:52:27 -0800 | [diff] [blame] | 1582 | static int thread_cpu_clock_getres(const clockid_t which_clock, |
| 1583 | struct timespec *tp) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1584 | { |
| 1585 | return posix_cpu_clock_getres(THREAD_CLOCK, tp); |
| 1586 | } |
Thomas Gleixner | a924b04 | 2006-01-09 20:52:27 -0800 | [diff] [blame] | 1587 | static int thread_cpu_clock_get(const clockid_t which_clock, |
| 1588 | struct timespec *tp) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1589 | { |
| 1590 | return posix_cpu_clock_get(THREAD_CLOCK, tp); |
| 1591 | } |
| 1592 | static int thread_cpu_timer_create(struct k_itimer *timer) |
| 1593 | { |
| 1594 | timer->it_clock = THREAD_CLOCK; |
| 1595 | return posix_cpu_timer_create(timer); |
| 1596 | } |
Thomas Gleixner | a924b04 | 2006-01-09 20:52:27 -0800 | [diff] [blame] | 1597 | static int thread_cpu_nsleep(const clockid_t which_clock, int flags, |
Thomas Gleixner | 97735f2 | 2006-01-09 20:52:37 -0800 | [diff] [blame] | 1598 | struct timespec *rqtp, struct timespec __user *rmtp) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1599 | { |
| 1600 | return -EINVAL; |
| 1601 | } |
Toyo Abe | 1711ef3 | 2006-09-29 02:00:28 -0700 | [diff] [blame] | 1602 | static long thread_cpu_nsleep_restart(struct restart_block *restart_block) |
| 1603 | { |
| 1604 | return -EINVAL; |
| 1605 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1606 | |
| 1607 | static __init int init_posix_cpu_timers(void) |
| 1608 | { |
| 1609 | struct k_clock process = { |
| 1610 | .clock_getres = process_cpu_clock_getres, |
| 1611 | .clock_get = process_cpu_clock_get, |
| 1612 | .clock_set = do_posix_clock_nosettime, |
| 1613 | .timer_create = process_cpu_timer_create, |
| 1614 | .nsleep = process_cpu_nsleep, |
Toyo Abe | 1711ef3 | 2006-09-29 02:00:28 -0700 | [diff] [blame] | 1615 | .nsleep_restart = process_cpu_nsleep_restart, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1616 | }; |
| 1617 | struct k_clock thread = { |
| 1618 | .clock_getres = thread_cpu_clock_getres, |
| 1619 | .clock_get = thread_cpu_clock_get, |
| 1620 | .clock_set = do_posix_clock_nosettime, |
| 1621 | .timer_create = thread_cpu_timer_create, |
| 1622 | .nsleep = thread_cpu_nsleep, |
Toyo Abe | 1711ef3 | 2006-09-29 02:00:28 -0700 | [diff] [blame] | 1623 | .nsleep_restart = thread_cpu_nsleep_restart, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1624 | }; |
Stanislaw Gruszka | 8356b5f | 2009-07-29 12:15:27 +0200 | [diff] [blame] | 1625 | struct timespec ts; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1626 | |
| 1627 | register_posix_clock(CLOCK_PROCESS_CPUTIME_ID, &process); |
| 1628 | register_posix_clock(CLOCK_THREAD_CPUTIME_ID, &thread); |
| 1629 | |
Stanislaw Gruszka | a42548a | 2009-07-29 12:15:29 +0200 | [diff] [blame] | 1630 | cputime_to_timespec(cputime_one_jiffy, &ts); |
Stanislaw Gruszka | 8356b5f | 2009-07-29 12:15:27 +0200 | [diff] [blame] | 1631 | onecputick = ts.tv_nsec; |
| 1632 | WARN_ON(ts.tv_sec != 0); |
| 1633 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1634 | return 0; |
| 1635 | } |
| 1636 | __initcall(init_posix_cpu_timers); |