+ mm-oom-do-not-check-0-mask-in-out_of_memory.patch added to mm-unstable branch

+ mm-oom-do-not-check-0-mask-in-out_of_memory.patch added to mm-unstable branch

[Andrew Morton]

The patch titled
     Subject: mm, oom: do not check 0 mask in out_of_memory()
has been added to the -mm mm-unstable branch.  Its filename is
     mm-oom-do-not-check-0-mask-in-out_of_memory.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-oom-do-not-check-0-mask-in-out_of_memory.patch

This patch will later appear in the mm-unstable branch at
    git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Before you just go and hit "reply", please:
   a) Consider who else should be cc'ed
   b) Prefer to cc a suitable mailing list as well
   c) Ideally: find the original patch on the mailing list and do a
      reply-to-all to that, adding suitable additional cc's

*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***

The -mm tree is included into linux-next via the mm-everything
branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
and is updated there every 2-3 working days

------------------------------------------------------
From: Haifeng Xu <haifeng.xu@shopee.com>
Subject: mm, oom: do not check 0 mask in out_of_memory()
Date: Mon, 8 May 2023 07:35:38 +0000

Since commit 60e2793d440a ("mm, oom: do not trigger out_of_memory from the
#PF"), no user sets gfp_mask to 0.  Remove the 0 mask check and update the
comments.

Link: https://lkml.kernel.org/r/20230508073538.1168-1-haifeng.xu@shopee.com
Signed-off-by: Haifeng Xu <haifeng.xu@shopee.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Shakeel Butt <shakeelb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/oom_kill.c |    8 +++-----
 1 file changed, 3 insertions(+), 5 deletions(-)

--- a/mm/oom_kill.c~mm-oom-do-not-check-0-mask-in-out_of_memory
+++ a/mm/oom_kill.c
@@ -1130,12 +1130,10 @@ bool out_of_memory(struct oom_control *o
 
 	/*
 	 * The OOM killer does not compensate for IO-less reclaim.
-	 * pagefault_out_of_memory lost its gfp context so we have to
-	 * make sure exclude 0 mask - all other users should have at least
-	 * ___GFP_DIRECT_RECLAIM to get here. But mem_cgroup_oom() has to
-	 * invoke the OOM killer even if it is a GFP_NOFS allocation.
+	 * But mem_cgroup_oom() has to invoke the OOM killer even
+	 * if it is a GFP_NOFS allocation.
 	 */
-	if (oc->gfp_mask && !(oc->gfp_mask & __GFP_FS) && !is_memcg_oom(oc))
+	if (!(oc->gfp_mask & __GFP_FS) && !is_memcg_oom(oc))
 		return true;
 
 	/*
_

Patches currently in -mm which might be from haifeng.xu@shopee.com are

memcg-oom-remove-unnecessary-check-in-mem_cgroup_oom_synchronize.patch
memcg-oom-remove-explicit-wakeup-in-mem_cgroup_oom_synchronize.patch
mm-oom-do-not-check-0-mask-in-out_of_memory.patch