+ mm-nommu-set-mmf_oom_skip-in-exit_mmap.patch added to mm-unstable branch

+ mm-nommu-set-mmf_oom_skip-in-exit_mmap.patch added to mm-unstable branch

[Andrew Morton]

The patch titled
     Subject: mm: nommu: set MMF_OOM_SKIP in exit_mmap()
has been added to the -mm mm-unstable branch.  Its filename is
     mm-nommu-set-mmf_oom_skip-in-exit_mmap.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-nommu-set-mmf_oom_skip-in-exit_mmap.patch

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

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------------------------------------------------------
From: Alexis Bouzigues <BouziguesAlexis@JohnDeere.com>
Subject: mm: nommu: set MMF_OOM_SKIP in exit_mmap()
Date: Tue, 13 Oct 2026 17:56:19 -0500

Commit 212925802454 ("mm: oom: let oom_reap_task and exit_mmap run
concurrently") moved setting MMF_OOM_SKIP from __mmput() into the MMU
exit_mmap(), so it is no longer set when a NOMMU mm is torn down.

As a result, a NOMMU OOM victim that has exited and freed its memory keeps
the OOM killer from selecting another victim until it is reaped.

Set MMF_OOM_SKIP in the NOMMU exit_mmap() once the VMAs are freed, as the
MMU version does.

Link: https://lore.kernel.org/20261013-fix-nommu-exit-mmap-oom-skip-v1-1-cb957cdbfcc3@JohnDeere.com
Fixes: 212925802454 ("mm: oom: let oom_reap_task and exit_mmap run concurrently")
Signed-off-by: Alexis Bouzigues <BouziguesAlexis@JohnDeere.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Assisted-by: LLM
Cc: Michal Hocko <mhocko@suse.com>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Lorenzo Stoakes <ljs@kernel.org>
---

 mm/nommu.c |    1 +
 1 file changed, 1 insertion(+)

--- a/mm/nommu.c~mm-nommu-set-mmf_oom_skip-in-exit_mmap
+++ a/mm/nommu.c
@@ -1555,6 +1555,7 @@ void exit_mmap(struct mm_struct *mm)
 		delete_vma(mm, vma);
 		cond_resched();
 	}
+	mm_flags_set(MMF_OOM_SKIP, mm);
 	__mt_destroy(&mm->mm_mt);
 	mmap_write_unlock(mm);
 }
_

Patches currently in -mm which might be from BouziguesAlexis@JohnDeere.com are

mm-nommu-set-mmf_oom_skip-in-exit_mmap.patch