The patch titled
Subject: mm-avoid-zeroing-user-movable-page-twice-with-init_on_alloc=1-fix
has been added to the -mm mm-unstable branch. Its filename is
mm-avoid-zeroing-user-movable-page-twice-with-init_on_alloc=1-fix.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-avoid-zeroing-user-movable-page-twice-with-init_on_alloc=1-fix.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: Zi Yan <ziy@xxxxxxxxxx>
Subject: mm-avoid-zeroing-user-movable-page-twice-with-init_on_alloc=1-fix
Date: Tue, 22 Oct 2024 10:33:40 -0400
comment fixes, per David
Link: https://lkml.kernel.org/r/97DB52E1-C594-49B5-9736-89AC302FAB01@xxxxxxxxxx
Signed-off-by: Zi Yan <ziy@xxxxxxxxxx>
Cc: Alexander Potapenko <glider@xxxxxxxxxx>
Cc: David Hildenbrand <david@xxxxxxxxxx>
Cc: "Huang, Ying" <ying.huang@xxxxxxxxx>
Cc: John Hubbard <jhubbard@xxxxxxxxxx>
Cc: Kees Cook <keescook@xxxxxxxxxxxx>
Cc: Kefeng Wang <wangkefeng.wang@xxxxxxxxxx>
Cc: Matthew Wilcox <willy@xxxxxxxxxxxxx>
Cc: Miaohe Lin <linmiaohe@xxxxxxxxxx>
Cc: Ryan Roberts <ryan.roberts@xxxxxxx>
Cc: Vlastimil Babka <vbabka@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/huge_memory.c | 5 +++++
mm/memory.c | 7 +++++++
2 files changed, 12 insertions(+)
--- a/mm/huge_memory.c~mm-avoid-zeroing-user-movable-page-twice-with-init_on_alloc=1-fix
+++ a/mm/huge_memory.c
@@ -1165,6 +1165,11 @@ static struct folio *vma_alloc_anon_foli
}
folio_throttle_swaprate(folio, gfp);
+ /*
+ * When a folio is not zeroed during allocation (__GFP_ZERO not used),
+ * folio_zero_user() is used to make sure that the page corresponding
+ * to the faulting address will be hot in the cache after zeroing.
+ */
if (!alloc_zeroed())
folio_zero_user(folio, addr);
/*
--- a/mm/memory.c~mm-avoid-zeroing-user-movable-page-twice-with-init_on_alloc=1-fix
+++ a/mm/memory.c
@@ -4719,6 +4719,13 @@ static struct folio *alloc_anon_folio(st
goto next;
}
folio_throttle_swaprate(folio, gfp);
+ /*
+ * When a folio is not zeroed during allocation
+ * (__GFP_ZERO not used), folio_zero_user() is used
+ * to make sure that the page corresponding to the
+ * faulting address will be hot in the cache after
+ * zeroing.
+ */
if (!alloc_zeroed())
folio_zero_user(folio, vmf->address);
return folio;
_
Patches currently in -mm which might be from ziy@xxxxxxxxxx are
mm-avoid-vm_bug_on-when-try-to-map-an-anon-large-folio-to-zero-page.patch
mm-avoid-zeroing-user-movable-page-twice-with-init_on_alloc=1.patch
mm-avoid-zeroing-user-movable-page-twice-with-init_on_alloc=1-fix.patch
