mm/oom_kill.c: clean up oom_reap_task_mm()
Andrew has noticed some inconsistencies in oom_reap_task_mm. Notably - Undocumented return value. - comment "failed to reap part..." is misleading - sounds like it's referring to something which happened in the past, is in fact referring to something which might happen in the future. - fails to call trace_finish_task_reaping() in one case - code duplication. - Increases mmap_sem hold time a little by moving trace_finish_task_reaping() inside the locked region. So sue me ;) - Sharing the finish: path means that the trace event won't distinguish between the two sources of finishing. Add a short explanation for the return value and fix the rest by reorganizing the function a bit to have unified function exit paths. Link: http://lkml.kernel.org/r/20180724141747.GP28386@dhcp22.suse.cz Suggested-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Michal Hocko <mhocko@suse.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>hifive-unleashed-5.1
parent
c3b78b11ef
commit
431f42fdfd
|
@ -534,8 +534,16 @@ bool __oom_reap_task_mm(struct mm_struct *mm)
|
||||||
return ret;
|
return ret;
|
||||||
}
|
}
|
||||||
|
|
||||||
|
/*
|
||||||
|
* Reaps the address space of the give task.
|
||||||
|
*
|
||||||
|
* Returns true on success and false if none or part of the address space
|
||||||
|
* has been reclaimed and the caller should retry later.
|
||||||
|
*/
|
||||||
static bool oom_reap_task_mm(struct task_struct *tsk, struct mm_struct *mm)
|
static bool oom_reap_task_mm(struct task_struct *tsk, struct mm_struct *mm)
|
||||||
{
|
{
|
||||||
|
bool ret = true;
|
||||||
|
|
||||||
if (!down_read_trylock(&mm->mmap_sem)) {
|
if (!down_read_trylock(&mm->mmap_sem)) {
|
||||||
trace_skip_task_reaping(tsk->pid);
|
trace_skip_task_reaping(tsk->pid);
|
||||||
return false;
|
return false;
|
||||||
|
@ -548,28 +556,28 @@ static bool oom_reap_task_mm(struct task_struct *tsk, struct mm_struct *mm)
|
||||||
* down_write();up_write() cycle in exit_mmap().
|
* down_write();up_write() cycle in exit_mmap().
|
||||||
*/
|
*/
|
||||||
if (test_bit(MMF_OOM_SKIP, &mm->flags)) {
|
if (test_bit(MMF_OOM_SKIP, &mm->flags)) {
|
||||||
up_read(&mm->mmap_sem);
|
|
||||||
trace_skip_task_reaping(tsk->pid);
|
trace_skip_task_reaping(tsk->pid);
|
||||||
return true;
|
goto out_unlock;
|
||||||
}
|
}
|
||||||
|
|
||||||
trace_start_task_reaping(tsk->pid);
|
trace_start_task_reaping(tsk->pid);
|
||||||
|
|
||||||
/* failed to reap part of the address space. Try again later */
|
/* failed to reap part of the address space. Try again later */
|
||||||
if (!__oom_reap_task_mm(mm)) {
|
ret = __oom_reap_task_mm(mm);
|
||||||
up_read(&mm->mmap_sem);
|
if (!ret)
|
||||||
return false;
|
goto out_finish;
|
||||||
}
|
|
||||||
|
|
||||||
pr_info("oom_reaper: reaped process %d (%s), now anon-rss:%lukB, file-rss:%lukB, shmem-rss:%lukB\n",
|
pr_info("oom_reaper: reaped process %d (%s), now anon-rss:%lukB, file-rss:%lukB, shmem-rss:%lukB\n",
|
||||||
task_pid_nr(tsk), tsk->comm,
|
task_pid_nr(tsk), tsk->comm,
|
||||||
K(get_mm_counter(mm, MM_ANONPAGES)),
|
K(get_mm_counter(mm, MM_ANONPAGES)),
|
||||||
K(get_mm_counter(mm, MM_FILEPAGES)),
|
K(get_mm_counter(mm, MM_FILEPAGES)),
|
||||||
K(get_mm_counter(mm, MM_SHMEMPAGES)));
|
K(get_mm_counter(mm, MM_SHMEMPAGES)));
|
||||||
|
out_finish:
|
||||||
|
trace_finish_task_reaping(tsk->pid);
|
||||||
|
out_unlock:
|
||||||
up_read(&mm->mmap_sem);
|
up_read(&mm->mmap_sem);
|
||||||
|
|
||||||
trace_finish_task_reaping(tsk->pid);
|
return ret;
|
||||||
return true;
|
|
||||||
}
|
}
|
||||||
|
|
||||||
#define MAX_OOM_REAP_RETRIES 10
|
#define MAX_OOM_REAP_RETRIES 10
|
||||||
|
|
Loading…
Reference in New Issue