mm, counters: remove task argument to sync_mm_rss() and __sync_task_rss_stat()

sync_mm_rss() can only be used for current to avoid race conditions in
iterating and clearing its per-task counters.  Remove the task argument
for it and its helper function, __sync_task_rss_stat(), to avoid thinking
it can be used safely for anything other than current.

Signed-off-by: David Rientjes <rientjes@google.com>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
David Rientjes 2012-03-21 16:34:13 -07:00 committed by Linus Torvalds
parent 90481622d7
commit 05af2e104a
5 changed files with 14 additions and 14 deletions

View File

@ -824,7 +824,7 @@ static int exec_mmap(struct mm_struct *mm)
/* Notify parent that we're no longer interested in the old VM */
tsk = current;
old_mm = current->mm;
sync_mm_rss(tsk, old_mm);
sync_mm_rss(old_mm);
mm_release(tsk, old_mm);
if (old_mm) {

View File

@ -1131,9 +1131,9 @@ static inline void setmax_mm_hiwater_rss(unsigned long *maxrss,
}
#if defined(SPLIT_RSS_COUNTING)
void sync_mm_rss(struct task_struct *task, struct mm_struct *mm);
void sync_mm_rss(struct mm_struct *mm);
#else
static inline void sync_mm_rss(struct task_struct *task, struct mm_struct *mm)
static inline void sync_mm_rss(struct mm_struct *mm)
{
}
#endif

View File

@ -934,7 +934,7 @@ void do_exit(long code)
acct_update_integrals(tsk);
/* sync mm's RSS info before statistics gathering */
if (tsk->mm)
sync_mm_rss(tsk, tsk->mm);
sync_mm_rss(tsk->mm);
group_dead = atomic_dec_and_test(&tsk->signal->live);
if (group_dead) {
hrtimer_cancel(&tsk->signal->real_timer);

View File

@ -125,17 +125,17 @@ core_initcall(init_zero_pfn);
#if defined(SPLIT_RSS_COUNTING)
static void __sync_task_rss_stat(struct task_struct *task, struct mm_struct *mm)
static void __sync_task_rss_stat(struct mm_struct *mm)
{
int i;
for (i = 0; i < NR_MM_COUNTERS; i++) {
if (task->rss_stat.count[i]) {
add_mm_counter(mm, i, task->rss_stat.count[i]);
task->rss_stat.count[i] = 0;
if (current->rss_stat.count[i]) {
add_mm_counter(mm, i, current->rss_stat.count[i]);
current->rss_stat.count[i] = 0;
}
}
task->rss_stat.events = 0;
current->rss_stat.events = 0;
}
static void add_mm_counter_fast(struct mm_struct *mm, int member, int val)
@ -157,12 +157,12 @@ static void check_sync_rss_stat(struct task_struct *task)
if (unlikely(task != current))
return;
if (unlikely(task->rss_stat.events++ > TASK_RSS_EVENTS_THRESH))
__sync_task_rss_stat(task, task->mm);
__sync_task_rss_stat(task->mm);
}
void sync_mm_rss(struct task_struct *task, struct mm_struct *mm)
void sync_mm_rss(struct mm_struct *mm)
{
__sync_task_rss_stat(task, mm);
__sync_task_rss_stat(mm);
}
#else /* SPLIT_RSS_COUNTING */
@ -643,7 +643,7 @@ static inline void add_mm_rss_vec(struct mm_struct *mm, int *rss)
int i;
if (current->mm == mm)
sync_mm_rss(current, mm);
sync_mm_rss(mm);
for (i = 0; i < NR_MM_COUNTERS; i++)
if (rss[i])
add_mm_counter(mm, i, rss[i]);

View File

@ -53,7 +53,7 @@ void unuse_mm(struct mm_struct *mm)
struct task_struct *tsk = current;
task_lock(tsk);
sync_mm_rss(tsk, mm);
sync_mm_rss(mm);
tsk->mm = NULL;
/* active_mm is still 'mm' */
enter_lazy_tlb(mm, tsk);