[PATCH] ifdef ->rchar, ->wchar, ->syscr, ->syscw from task_struct
They are fat: 4x8 bytes in task_struct.
They are uncoditionally updated in every fork, read, write and sendfile.
They are used only if you have some "extended acct fields feature".
And please, please, please, read(2) knows about bytes, not characters,
why it is called "rchar"?
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Jay Lan <jlan@engr.sgi.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/fs/proc/base.c b/fs/proc/base.c
index 1a979ea..7fb37d6 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -1810,17 +1810,21 @@
static int proc_pid_io_accounting(struct task_struct *task, char *buffer)
{
return sprintf(buffer,
+#ifdef CONFIG_TASK_XACCT
"rchar: %llu\n"
"wchar: %llu\n"
"syscr: %llu\n"
"syscw: %llu\n"
+#endif
"read_bytes: %llu\n"
"write_bytes: %llu\n"
"cancelled_write_bytes: %llu\n",
+#ifdef CONFIG_TASK_XACCT
(unsigned long long)task->rchar,
(unsigned long long)task->wchar,
(unsigned long long)task->syscr,
(unsigned long long)task->syscw,
+#endif
(unsigned long long)task->ioac.read_bytes,
(unsigned long long)task->ioac.write_bytes,
(unsigned long long)task->ioac.cancelled_write_bytes);
diff --git a/fs/read_write.c b/fs/read_write.c
index 707ac21..bcb0ef2 100644
--- a/fs/read_write.c
+++ b/fs/read_write.c
@@ -274,9 +274,9 @@
ret = do_sync_read(file, buf, count, pos);
if (ret > 0) {
fsnotify_access(file->f_path.dentry);
- current->rchar += ret;
+ add_rchar(current, ret);
}
- current->syscr++;
+ inc_syscr(current);
}
}
@@ -332,9 +332,9 @@
ret = do_sync_write(file, buf, count, pos);
if (ret > 0) {
fsnotify_modify(file->f_path.dentry);
- current->wchar += ret;
+ add_wchar(current, ret);
}
- current->syscw++;
+ inc_syscw(current);
}
}
@@ -675,8 +675,8 @@
}
if (ret > 0)
- current->rchar += ret;
- current->syscr++;
+ add_rchar(current, ret);
+ inc_syscr(current);
return ret;
}
@@ -696,8 +696,8 @@
}
if (ret > 0)
- current->wchar += ret;
- current->syscw++;
+ add_wchar(current, ret);
+ inc_syscw(current);
return ret;
}
@@ -779,12 +779,12 @@
retval = in_file->f_op->sendfile(in_file, ppos, count, file_send_actor, out_file);
if (retval > 0) {
- current->rchar += retval;
- current->wchar += retval;
+ add_rchar(current, retval);
+ add_wchar(current, retval);
}
- current->syscr++;
- current->syscw++;
+ inc_syscr(current);
+ inc_syscw(current);
if (*ppos > max)
retval = -EOVERFLOW;
diff --git a/include/linux/sched.h b/include/linux/sched.h
index 4463735..76c8e2d 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -1013,8 +1013,10 @@
* to a stack based synchronous wait) if its doing sync IO.
*/
wait_queue_t *io_wait;
+#ifdef CONFIG_TASK_XACCT
/* i/o counters(bytes read/written, #syscalls */
u64 rchar, wchar, syscr, syscw;
+#endif
struct task_io_accounting ioac;
#if defined(CONFIG_TASK_XACCT)
u64 acct_rss_mem1; /* accumulated rss usage */
@@ -1649,6 +1651,44 @@
extern void normalize_rt_tasks(void);
+#ifdef CONFIG_TASK_XACCT
+static inline void add_rchar(struct task_struct *tsk, ssize_t amt)
+{
+ tsk->rchar += amt;
+}
+
+static inline void add_wchar(struct task_struct *tsk, ssize_t amt)
+{
+ tsk->wchar += amt;
+}
+
+static inline void inc_syscr(struct task_struct *tsk)
+{
+ tsk->syscr++;
+}
+
+static inline void inc_syscw(struct task_struct *tsk)
+{
+ tsk->syscw++;
+}
+#else
+static inline void add_rchar(struct task_struct *tsk, ssize_t amt)
+{
+}
+
+static inline void add_wchar(struct task_struct *tsk, ssize_t amt)
+{
+}
+
+static inline void inc_syscr(struct task_struct *tsk)
+{
+}
+
+static inline void inc_syscw(struct task_struct *tsk)
+{
+}
+#endif
+
#endif /* __KERNEL__ */
#endif
diff --git a/kernel/fork.c b/kernel/fork.c
index d57118d..80284eb 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -1038,10 +1038,12 @@
p->utime = cputime_zero;
p->stime = cputime_zero;
p->sched_time = 0;
+#ifdef CONFIG_TASK_XACCT
p->rchar = 0; /* I/O counter: bytes read */
p->wchar = 0; /* I/O counter: bytes written */
p->syscr = 0; /* I/O counter: read syscalls */
p->syscw = 0; /* I/O counter: write syscalls */
+#endif
task_io_accounting_init(p);
acct_clear_integrals(p);