The patch titled
Subject: mm/oom_kill.c: clean up oom_reap_task_mm()
has been removed from the -mm tree. Its filename was
mm-oom_killc-clean-up-oom_reap_task_mm.patch
This patch was dropped because it was merged into mainline or a subsystem tree
------------------------------------------------------
From: Michal Hocko <mhocko@xxxxxxxxxx>
Subject: mm/oom_kill.c: clean up oom_reap_task_mm()
Andrew has noticed someinconsistencies 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@xxxxxxxxxxxxxx
Suggested-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Michal Hocko <mhocko@xxxxxxxx>
Reviewed-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: Tetsuo Handa <penguin-kernel@xxxxxxxxxxxxxxxxxxx>
Cc: David Rientjes <rientjes@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/oom_kill.c | 24 ++++++++++++++++--------
1 file changed, 16 insertions(+), 8 deletions(-)
--- a/mm/oom_kill.c~mm-oom_killc-clean-up-oom_reap_task_mm
+++ a/mm/oom_kill.c
@@ -534,8 +534,16 @@ bool __oom_reap_task_mm(struct mm_struct
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)
{
+ bool ret = true;
+
if (!down_read_trylock(&mm->mmap_sem)) {
trace_skip_task_reaping(tsk->pid);
return false;
@@ -548,28 +556,28 @@ static bool oom_reap_task_mm(struct task
* down_write();up_write() cycle in exit_mmap().
*/
if (test_bit(MMF_OOM_SKIP, &mm->flags)) {
- up_read(&mm->mmap_sem);
trace_skip_task_reaping(tsk->pid);
- return true;
+ goto out_unlock;
}
trace_start_task_reaping(tsk->pid);
/* failed to reap part of the address space. Try again later */
- if (!__oom_reap_task_mm(mm)) {
- up_read(&mm->mmap_sem);
- return false;
- }
+ ret = __oom_reap_task_mm(mm);
+ if (!ret)
+ goto out_finish;
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,
K(get_mm_counter(mm, MM_ANONPAGES)),
K(get_mm_counter(mm, MM_FILEPAGES)),
K(get_mm_counter(mm, MM_SHMEMPAGES)));
+out_finish:
+ trace_finish_task_reaping(tsk->pid);
+out_unlock:
up_read(&mm->mmap_sem);
- trace_finish_task_reaping(tsk->pid);
- return true;
+ return ret;
}
#define MAX_OOM_REAP_RETRIES 10
_
Patches currently in -mm which might be from mhocko@xxxxxxxxxx are
