mm, oom: change type of oom_score_adj to short
The maximum oom_score_adj is 1000 and the minimum oom_score_adj is -1000,
so this range can be represented by the signed short type with no
functional change. The extra space this frees up in struct signal_struct
will be used for per-thread oom kill flags in the next patch.
Signed-off-by: David Rientjes <rientjes@google.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Reviewed-by: Michal Hocko <mhocko@suse.cz>
Cc: Anton Vorontsov <anton.vorontsov@linaro.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/drivers/staging/android/lowmemorykiller.c b/drivers/staging/android/lowmemorykiller.c
index b91e4bc..3b91b0f 100644
--- a/drivers/staging/android/lowmemorykiller.c
+++ b/drivers/staging/android/lowmemorykiller.c
@@ -40,7 +40,7 @@
#include <linux/notifier.h>
static uint32_t lowmem_debug_level = 2;
-static int lowmem_adj[6] = {
+static short lowmem_adj[6] = {
0,
1,
6,
@@ -70,9 +70,9 @@
int rem = 0;
int tasksize;
int i;
- int min_score_adj = OOM_SCORE_ADJ_MAX + 1;
+ short min_score_adj = OOM_SCORE_ADJ_MAX + 1;
int selected_tasksize = 0;
- int selected_oom_score_adj;
+ short selected_oom_score_adj;
int array_size = ARRAY_SIZE(lowmem_adj);
int other_free = global_page_state(NR_FREE_PAGES);
int other_file = global_page_state(NR_FILE_PAGES) -
@@ -90,7 +90,7 @@
}
}
if (sc->nr_to_scan > 0)
- lowmem_print(3, "lowmem_shrink %lu, %x, ofree %d %d, ma %d\n",
+ lowmem_print(3, "lowmem_shrink %lu, %x, ofree %d %d, ma %hd\n",
sc->nr_to_scan, sc->gfp_mask, other_free,
other_file, min_score_adj);
rem = global_page_state(NR_ACTIVE_ANON) +
@@ -107,7 +107,7 @@
rcu_read_lock();
for_each_process(tsk) {
struct task_struct *p;
- int oom_score_adj;
+ short oom_score_adj;
if (tsk->flags & PF_KTHREAD)
continue;
@@ -141,11 +141,11 @@
selected = p;
selected_tasksize = tasksize;
selected_oom_score_adj = oom_score_adj;
- lowmem_print(2, "select %d (%s), adj %d, size %d, to kill\n",
+ lowmem_print(2, "select %d (%s), adj %hd, size %d, to kill\n",
p->pid, p->comm, oom_score_adj, tasksize);
}
if (selected) {
- lowmem_print(1, "send sigkill to %d (%s), adj %d, size %d\n",
+ lowmem_print(1, "send sigkill to %d (%s), adj %hd, size %d\n",
selected->pid, selected->comm,
selected_oom_score_adj, selected_tasksize);
lowmem_deathpending_timeout = jiffies + HZ;
@@ -176,7 +176,7 @@
}
module_param_named(cost, lowmem_shrinker.seeks, int, S_IRUGO | S_IWUSR);
-module_param_array_named(adj, lowmem_adj, int, &lowmem_adj_size,
+module_param_array_named(adj, lowmem_adj, short, &lowmem_adj_size,
S_IRUGO | S_IWUSR);
module_param_array_named(minfree, lowmem_minfree, uint, &lowmem_minfree_size,
S_IRUGO | S_IWUSR);
diff --git a/fs/proc/base.c b/fs/proc/base.c
index 9e28356..aa63d25 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -985,7 +985,7 @@
{
struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode);
char buffer[PROC_NUMBUF];
- int oom_score_adj = OOM_SCORE_ADJ_MIN;
+ short oom_score_adj = OOM_SCORE_ADJ_MIN;
unsigned long flags;
size_t len;
@@ -996,7 +996,7 @@
unlock_task_sighand(task, &flags);
}
put_task_struct(task);
- len = snprintf(buffer, sizeof(buffer), "%d\n", oom_score_adj);
+ len = snprintf(buffer, sizeof(buffer), "%hd\n", oom_score_adj);
return simple_read_from_buffer(buf, count, ppos, buffer, len);
}
@@ -1043,15 +1043,15 @@
goto err_task_lock;
}
- if (oom_score_adj < task->signal->oom_score_adj_min &&
+ if ((short)oom_score_adj < task->signal->oom_score_adj_min &&
!capable(CAP_SYS_RESOURCE)) {
err = -EACCES;
goto err_sighand;
}
- task->signal->oom_score_adj = oom_score_adj;
+ task->signal->oom_score_adj = (short)oom_score_adj;
if (has_capability_noaudit(current, CAP_SYS_RESOURCE))
- task->signal->oom_score_adj_min = oom_score_adj;
+ task->signal->oom_score_adj_min = (short)oom_score_adj;
trace_oom_score_adj_update(task);
err_sighand:
diff --git a/include/linux/oom.h b/include/linux/oom.h
index 4a4188d..922dab1 100644
--- a/include/linux/oom.h
+++ b/include/linux/oom.h
@@ -29,8 +29,8 @@
OOM_SCAN_SELECT, /* always select this thread first */
};
-extern void compare_swap_oom_score_adj(int old_val, int new_val);
-extern int test_set_oom_score_adj(int new_val);
+extern void compare_swap_oom_score_adj(short old_val, short new_val);
+extern short test_set_oom_score_adj(short new_val);
extern unsigned long oom_badness(struct task_struct *p,
struct mem_cgroup *memcg, const nodemask_t *nodemask,
diff --git a/include/linux/sched.h b/include/linux/sched.h
index 0dd42a0..ed30456 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -631,9 +631,9 @@
struct rw_semaphore group_rwsem;
#endif
- int oom_score_adj; /* OOM kill score adjustment */
- int oom_score_adj_min; /* OOM kill score adjustment minimum value.
- * Only settable by CAP_SYS_RESOURCE. */
+ short oom_score_adj; /* OOM kill score adjustment */
+ short oom_score_adj_min; /* OOM kill score adjustment min value.
+ * Only settable by CAP_SYS_RESOURCE. */
struct mutex cred_guard_mutex; /* guard against foreign influences on
* credential calculations
diff --git a/include/trace/events/oom.h b/include/trace/events/oom.h
index dd4ba3b..1e97498 100644
--- a/include/trace/events/oom.h
+++ b/include/trace/events/oom.h
@@ -14,7 +14,7 @@
TP_STRUCT__entry(
__field( pid_t, pid)
__array( char, comm, TASK_COMM_LEN )
- __field( int, oom_score_adj)
+ __field( short, oom_score_adj)
),
TP_fast_assign(
@@ -23,7 +23,7 @@
__entry->oom_score_adj = task->signal->oom_score_adj;
),
- TP_printk("pid=%d comm=%s oom_score_adj=%d",
+ TP_printk("pid=%d comm=%s oom_score_adj=%hd",
__entry->pid, __entry->comm, __entry->oom_score_adj)
);
diff --git a/include/trace/events/task.h b/include/trace/events/task.h
index b53add0..102a646 100644
--- a/include/trace/events/task.h
+++ b/include/trace/events/task.h
@@ -15,7 +15,7 @@
__field( pid_t, pid)
__array( char, comm, TASK_COMM_LEN)
__field( unsigned long, clone_flags)
- __field( int, oom_score_adj)
+ __field( short, oom_score_adj)
),
TP_fast_assign(
@@ -25,7 +25,7 @@
__entry->oom_score_adj = task->signal->oom_score_adj;
),
- TP_printk("pid=%d comm=%s clone_flags=%lx oom_score_adj=%d",
+ TP_printk("pid=%d comm=%s clone_flags=%lx oom_score_adj=%hd",
__entry->pid, __entry->comm,
__entry->clone_flags, __entry->oom_score_adj)
);
@@ -40,7 +40,7 @@
__field( pid_t, pid)
__array( char, oldcomm, TASK_COMM_LEN)
__array( char, newcomm, TASK_COMM_LEN)
- __field( int, oom_score_adj)
+ __field( short, oom_score_adj)
),
TP_fast_assign(
@@ -50,7 +50,7 @@
__entry->oom_score_adj = task->signal->oom_score_adj;
),
- TP_printk("pid=%d oldcomm=%s newcomm=%s oom_score_adj=%d",
+ TP_printk("pid=%d oldcomm=%s newcomm=%s oom_score_adj=%hd",
__entry->pid, __entry->oldcomm,
__entry->newcomm, __entry->oom_score_adj)
);
diff --git a/mm/ksm.c b/mm/ksm.c
index 31ae5ea..b4d5a9d 100644
--- a/mm/ksm.c
+++ b/mm/ksm.c
@@ -1919,7 +1919,7 @@
if (ksm_run != flags) {
ksm_run = flags;
if (flags & KSM_RUN_UNMERGE) {
- int oom_score_adj;
+ short oom_score_adj;
oom_score_adj = test_set_oom_score_adj(OOM_SCORE_ADJ_MAX);
err = unmerge_and_remove_all_rmap_items();
diff --git a/mm/oom_kill.c b/mm/oom_kill.c
index 7e9e911..37ab4c5 100644
--- a/mm/oom_kill.c
+++ b/mm/oom_kill.c
@@ -53,7 +53,7 @@
* @old_val. Usually used to reinstate a previous value to prevent racing with
* userspacing tuning the value in the interim.
*/
-void compare_swap_oom_score_adj(int old_val, int new_val)
+void compare_swap_oom_score_adj(short old_val, short new_val)
{
struct sighand_struct *sighand = current->sighand;
@@ -72,7 +72,7 @@
* synchronization and returns the old value. Usually used to temporarily
* set a value, save the old value in the caller, and then reinstate it later.
*/
-int test_set_oom_score_adj(int new_val)
+short test_set_oom_score_adj(short new_val)
{
struct sighand_struct *sighand = current->sighand;
int old_val;
@@ -193,7 +193,7 @@
if (!p)
return 0;
- adj = p->signal->oom_score_adj;
+ adj = (long)p->signal->oom_score_adj;
if (adj == OOM_SCORE_ADJ_MIN) {
task_unlock(p);
return 0;
@@ -399,7 +399,7 @@
continue;
}
- pr_info("[%5d] %5d %5d %8lu %8lu %7lu %8lu %5d %s\n",
+ pr_info("[%5d] %5d %5d %8lu %8lu %7lu %8lu %5hd %s\n",
task->pid, from_kuid(&init_user_ns, task_uid(task)),
task->tgid, task->mm->total_vm, get_mm_rss(task->mm),
task->mm->nr_ptes,
@@ -415,7 +415,7 @@
{
task_lock(current);
pr_warning("%s invoked oom-killer: gfp_mask=0x%x, order=%d, "
- "oom_score_adj=%d\n",
+ "oom_score_adj=%hd\n",
current->comm, gfp_mask, order,
current->signal->oom_score_adj);
cpuset_print_task_mems_allowed(current);
diff --git a/mm/swapfile.c b/mm/swapfile.c
index 0fbb452..bb6f6a0 100644
--- a/mm/swapfile.c
+++ b/mm/swapfile.c
@@ -1498,7 +1498,7 @@
struct address_space *mapping;
struct inode *inode;
struct filename *pathname;
- int oom_score_adj;
+ short oom_score_adj;
int i, type, prev;
int err;