The patch titled
Subject: mm: set pte writable while pte_soft_dirty() is true in do_swap_page()
has been added to the -mm mm-unstable branch. Its filename is
mm-set-pte-writable-while-pte_soft_dirty-is-true-in-do_swap_page.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-set-pte-writable-while-pte_soft_dirty-is-true-in-do_swap_page.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: Barry Song <v-songbaohua@xxxxxxxx>
Subject: mm: set pte writable while pte_soft_dirty() is true in do_swap_page()
Date: Sat, 8 Jun 2024 09:13:58 +1200
This patch leverages the new pte_needs_soft_dirty_wp() helper to optimize
a scenario where softdirty is enabled, but the softdirty flag has already
been set in do_swap_page(). In this situation, we can use pte_mkwrite
instead of applying write-protection since we don't depend on write
faults.
Link: https://lkml.kernel.org/r/20240607211358.4660-3-21cnbao@xxxxxxxxx
Signed-off-by: Barry Song <v-songbaohua@xxxxxxxx>
Suggested-by: David Hildenbrand <david@xxxxxxxxxx>
Cc: Chris Li <chrisl@xxxxxxxxxx>
Cc: Kairui Song <kasong@xxxxxxxxxxx>
Cc: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
Cc: Minchan Kim <minchan@xxxxxxxxxx>
Cc: Ryan Roberts <ryan.roberts@xxxxxxx>
Cc: Suren Baghdasaryan <surenb@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/memory.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/mm/memory.c~mm-set-pte-writable-while-pte_soft_dirty-is-true-in-do_swap_page
+++ a/mm/memory.c
@@ -4322,7 +4322,7 @@ check_folio:
if (!folio_test_ksm(folio) &&
(exclusive || folio_ref_count(folio) == 1)) {
if ((vma->vm_flags & VM_WRITE) && !userfaultfd_pte_wp(vma, pte) &&
- !vma_soft_dirty_enabled(vma)) {
+ !pte_needs_soft_dirty_wp(vma, pte)) {
pte = pte_mkwrite(pte, vma);
if (vmf->flags & FAULT_FLAG_WRITE) {
pte = pte_mkdirty(pte);
_
Patches currently in -mm which might be from v-songbaohua@xxxxxxxx are
mm-remove-the-implementation-of-swap_free-and-always-use-swap_free_nr.patch
mm-introduce-pte_move_swp_offset-helper-which-can-move-offset-bidirectionally.patch
mm-introduce-arch_do_swap_page_nr-which-allows-restore-metadata-for-nr-pages.patch
mm-swap-reuse-exclusive-folio-directly-instead-of-wp-page-faults.patch
mm-introduce-pmdpte_needs_soft_dirty_wp-helpers-for-softdirty-write-protect.patch
mm-set-pte-writable-while-pte_soft_dirty-is-true-in-do_swap_page.patch
