The process_mrelease() system call[1] is used to release the memory of
a dying process from the context of the caller, which is similar to and
uses the functions of the oom reaper logic. There exists trace logs for
a process when reaped by the oom reaper. Just extend the same to when
done by the process_mrelease() system call.
[1] https://lore.kernel.org/linux-mm/[email protected]/
Signed-off-by: Charan Teja Reddy <[email protected]>
---
mm/oom_kill.c | 14 +++++++++++++-
1 file changed, 13 insertions(+), 1 deletion(-)
diff --git a/mm/oom_kill.c b/mm/oom_kill.c
index 431d38c..8f4020a 100644
--- a/mm/oom_kill.c
+++ b/mm/oom_kill.c
@@ -941,7 +941,6 @@ static void __oom_kill_process(struct task_struct *victim, const char *message)
mmdrop(mm);
put_task_struct(victim);
}
-#undef K
/*
* Kill provided task unless it's secured by setting
@@ -1199,8 +1198,18 @@ SYSCALL_DEFINE2(process_mrelease, int, pidfd, unsigned int, flags)
ret = -EINTR;
goto drop_mm;
}
+ trace_start_task_reaping(task->pid);
if (!__oom_reap_task_mm(mm))
ret = -EAGAIN;
+ if (!ret) {
+ pr_info("process_mrelease: reaped process %d (%s), now anon-rss:%lukB, file-rss:%lukB, shmem-rss:%lukB oom_score_adj:%d\n",
+ task_pid_nr(task), task->comm,
+ K(get_mm_counter(mm, MM_ANONPAGES)),
+ K(get_mm_counter(mm, MM_FILEPAGES)),
+ K(get_mm_counter(mm, MM_SHMEMPAGES)),
+ task->signal->oom_score_adj);
+ }
+ trace_finish_task_reaping(task->pid);
mmap_read_unlock(mm);
drop_mm:
@@ -1208,9 +1217,12 @@ SYSCALL_DEFINE2(process_mrelease, int, pidfd, unsigned int, flags)
put_task:
put_task_struct(task);
put_pid:
+ if (ret && ret != -EAGAIN)
+ trace_skip_task_reaping(pid_vnr(pid));
put_pid(pid);
return ret;
#else
return -ENOSYS;
#endif /* CONFIG_MMU */
}
+#undef K
--
QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a
member of the Code Aurora Forum, hosted by The Linux Foundation
On Mon, Aug 16, 2021 at 2:39 AM Charan Teja Reddy
<[email protected]> wrote:
>
> The process_mrelease() system call[1] is used to release the memory of
> a dying process from the context of the caller, which is similar to and
> uses the functions of the oom reaper logic. There exists trace logs for
> a process when reaped by the oom reaper. Just extend the same to when
> done by the process_mrelease() system call.
>
> [1] https://lore.kernel.org/linux-mm/[email protected]/
>
> Signed-off-by: Charan Teja Reddy <[email protected]>
> ---
> mm/oom_kill.c | 14 +++++++++++++-
> 1 file changed, 13 insertions(+), 1 deletion(-)
>
> diff --git a/mm/oom_kill.c b/mm/oom_kill.c
> index 431d38c..8f4020a 100644
> --- a/mm/oom_kill.c
> +++ b/mm/oom_kill.c
> @@ -941,7 +941,6 @@ static void __oom_kill_process(struct task_struct *victim, const char *message)
> mmdrop(mm);
> put_task_struct(victim);
> }
> -#undef K
>
> /*
> * Kill provided task unless it's secured by setting
> @@ -1199,8 +1198,18 @@ SYSCALL_DEFINE2(process_mrelease, int, pidfd, unsigned int, flags)
> ret = -EINTR;
> goto drop_mm;
> }
> + trace_start_task_reaping(task->pid);
> if (!__oom_reap_task_mm(mm))
> ret = -EAGAIN;
> + if (!ret) {
> + pr_info("process_mrelease: reaped process %d (%s), now anon-rss:%lukB, file-rss:%lukB, shmem-rss:%lukB oom_score_adj:%d\n",
> + task_pid_nr(task), task->comm,
> + K(get_mm_counter(mm, MM_ANONPAGES)),
> + K(get_mm_counter(mm, MM_FILEPAGES)),
> + K(get_mm_counter(mm, MM_SHMEMPAGES)),
> + task->signal->oom_score_adj);
Tracing is good but I don't think we want this line to be flooding the
kernel logs. I would recommend either simply removing it or adding
another trace for this, so only folks interested in this info can get
it.