The patch titled
Subject: mm, oom: OOM sysrq should always kill a process
has been added to the -mm tree. Its filename is
mm-oom-oom-sysrq-should-always-kill-a-process.patch
This patch should soon appear at
https://ozlabs.org/~akpm/mmots/broken-out/mm-oom-oom-sysrq-should-always-kill-a-process.patch
and later at
https://ozlabs.org/~akpm/mmotm/broken-out/mm-oom-oom-sysrq-should-always-kill-a-process.patch
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------------------------------------------------------
From: Jann Horn <jannh@xxxxxxxxxx>
Subject: mm, oom: OOM sysrq should always kill a process
The OOM kill sysrq (alt+sysrq+F) should allow the user to kill the process
with the highest OOM badness with a single execution.
However, at the moment, the OOM kill can bail out if an OOM notifier (e.g.
the i915 one) says that it reclaimed a tiny amount of memory from
somewhere. That's probably not what the user wants.
As documented in struct oom_control, order == -1 means the oom kill is
required by sysrq. So check for that, and if it's true, don't bail out no
matter what the OOM notifiers say.
Link: https://lkml.kernel.org/r/20220105175115.605074-1-jannh@xxxxxxxxxx
Signed-off-by: Jann Horn <jannh@xxxxxxxxxx>
Cc: Martin Schwidefsky <schwidefsky@xxxxxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/oom_kill.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
--- a/mm/oom_kill.c~mm-oom-oom-sysrq-should-always-kill-a-process
+++ a/mm/oom_kill.c
@@ -1052,13 +1052,14 @@ EXPORT_SYMBOL_GPL(unregister_oom_notifie
bool out_of_memory(struct oom_control *oc)
{
unsigned long freed = 0;
+ bool sysrq_forced = oc->order == -1;
if (oom_killer_disabled)
return false;
if (!is_memcg_oom(oc)) {
blocking_notifier_call_chain(&oom_notify_list, 0, &freed);
- if (freed > 0)
+ if (freed > 0 && !sysrq_forced)
/* Got some memory back in the last second. */
return true;
}
_
Patches currently in -mm which might be from jannh@xxxxxxxxxx are
mm-oom-oom-sysrq-should-always-kill-a-process.patch
