The patch titled
Subject: fs/proc/page: respect folio head-page flag placement
has been added to the -mm mm-unstable branch. Its filename is
fs-proc-page-respect-folio-head-page-flag-placement.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/fs-proc-page-respect-folio-head-page-flag-placement.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: Kefeng Wang <wangkefeng.wang@xxxxxxxxxx>
Subject: fs/proc/page: respect folio head-page flag placement
Date: Fri, 10 Nov 2023 11:33:20 +0800
kpageflags reads page-flags directly from the page, even when the
respective flag is only updated on the headpage of a folio.
Since most flags are stored in head flags, make k = folio->flags, and add
new p = page->flags used for per-page flags.
Based upon a patch by Gregory Price.
Link: https://lkml.kernel.org/r/20231110033324.2455523-4-wangkefeng.wang@xxxxxxxxxx
Signed-off-by: Kefeng Wang <wangkefeng.wang@xxxxxxxxxx>
Suggested-by: Matthew Wilcox <willy@xxxxxxxxxxxxx>
Cc: Gregory Price <gregory.price@xxxxxxxxxxxx>
Cc: David Hildenbrand <david@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
fs/proc/page.c | 18 +++++++++---------
1 file changed, 9 insertions(+), 9 deletions(-)
--- a/fs/proc/page.c~fs-proc-page-respect-folio-head-page-flag-placement
+++ a/fs/proc/page.c
@@ -110,8 +110,7 @@ static inline u64 kpf_copy_bit(u64 kflag
u64 stable_page_flags(struct page *page)
{
struct folio *folio;
- u64 k;
- u64 u;
+ u64 k, p, u;
/*
* pseudo flag: KPF_NOPAGE
@@ -121,7 +120,8 @@ u64 stable_page_flags(struct page *page)
return 1 << KPF_NOPAGE;
folio = page_folio(page);
- k = page->flags;
+ k = folio->flags;
+ p = page->flags;
u = 0;
/*
@@ -202,7 +202,7 @@ u64 stable_page_flags(struct page *page)
u |= kpf_copy_bit(k, KPF_MLOCKED, PG_mlocked);
#ifdef CONFIG_MEMORY_FAILURE
- u |= kpf_copy_bit(k, KPF_HWPOISON, PG_hwpoison);
+ u |= kpf_copy_bit(p, KPF_HWPOISON, PG_hwpoison);
#endif
#ifdef CONFIG_ARCH_USES_PG_UNCACHED
@@ -211,13 +211,13 @@ u64 stable_page_flags(struct page *page)
u |= kpf_copy_bit(k, KPF_RESERVED, PG_reserved);
u |= kpf_copy_bit(k, KPF_MAPPEDTODISK, PG_mappedtodisk);
- u |= kpf_copy_bit(k, KPF_PRIVATE, PG_private);
- u |= kpf_copy_bit(k, KPF_PRIVATE_2, PG_private_2);
- u |= kpf_copy_bit(k, KPF_OWNER_PRIVATE, PG_owner_priv_1);
+ u |= kpf_copy_bit(p, KPF_PRIVATE, PG_private);
+ u |= kpf_copy_bit(p, KPF_PRIVATE_2, PG_private_2);
+ u |= kpf_copy_bit(p, KPF_OWNER_PRIVATE, PG_owner_priv_1);
u |= kpf_copy_bit(k, KPF_ARCH, PG_arch_1);
#ifdef CONFIG_ARCH_USES_PG_ARCH_X
- u |= kpf_copy_bit(k, KPF_ARCH_2, PG_arch_2);
- u |= kpf_copy_bit(k, KPF_ARCH_3, PG_arch_3);
+ u |= kpf_copy_bit(p, KPF_ARCH_2, PG_arch_2);
+ u |= kpf_copy_bit(p, KPF_ARCH_3, PG_arch_3);
#endif
return u;
_
Patches currently in -mm which might be from wangkefeng.wang@xxxxxxxxxx are
fs-proc-page-remove-unneeded-pagetail-pageslab-check.patch
fs-proc-page-use-a-folio-in-stable_page_flags.patch
fs-proc-page-respect-folio-head-page-flag-placement.patch
mm-huge_memory-use-more-folio-api-in-__split_huge_page_tail.patch
mm-task_mmu-use-a-folio-in-smaps_account.patch
mm-task_mmu-use-a-folio-in-clear_refs_pte_range.patch
page_idle-kill-page-idle-and-young-wrapper.patch
