The patch titled
Subject: mm: document mmu_notifier_invalidate_range_start_nonblock()
has been added to the -mm mm-unstable branch. Its filename is
mm-document-mmu_notifier_invalidate_range_start_nonblock.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-document-mmu_notifier_invalidate_range_start_nonblock.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: Jann Horn <jannh@xxxxxxxxxx>
Subject: mm: document mmu_notifier_invalidate_range_start_nonblock()
Date: Mon, 18 Sep 2023 22:18:32 +0200
Document what mmu_notifier_invalidate_range_start_nonblock() is for. Also
add a __must_check annotation to signal that callers must bail out if a
notifier vetoes the operation.
Link: https://lkml.kernel.org/r/20230918201832.265108-1-jannh@xxxxxxxxxx
Signed-off-by: Jann Horn <jannh@xxxxxxxxxx>
Reviewed-by: Jason Gunthorpe <jgg@xxxxxxxxxx>
Reviewed-by: Alistair Popple <apopple@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/linux/mmu_notifier.h | 9 ++++++++-
1 file changed, 8 insertions(+), 1 deletion(-)
--- a/include/linux/mmu_notifier.h~mm-document-mmu_notifier_invalidate_range_start_nonblock
+++ a/include/linux/mmu_notifier.h
@@ -459,7 +459,14 @@ mmu_notifier_invalidate_range_start(stru
lock_map_release(&__mmu_notifier_invalidate_range_start_map);
}
-static inline int
+/*
+ * This version of mmu_notifier_invalidate_range_start() avoids blocking, but it
+ * can return an error if a notifier can't proceed without blocking, in which
+ * case you're not allowed to modify PTEs in the specified range.
+ *
+ * This is mainly intended for OOM handling.
+ */
+static inline int __must_check
mmu_notifier_invalidate_range_start_nonblock(struct mmu_notifier_range *range)
{
int ret = 0;
_
Patches currently in -mm which might be from jannh@xxxxxxxxxx are
mm-document-mmu_notifier_invalidate_range_start_nonblock.patch
