The patch titled
Subject: mm/rmap: add helper to restart pgtable walk on changes
has been added to the -mm mm-unstable branch. Its filename is
mm-rmap-add-helper-to-restart-pgtable-walk-on-changes.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-rmap-add-helper-to-restart-pgtable-walk-on-changes.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: Lance Yang <ioworker0@xxxxxxxxx>
Subject: mm/rmap: add helper to restart pgtable walk on changes
Date: Mon, 10 Jun 2024 20:02:07 +0800
Introduce the page_vma_mapped_walk_restart() helper to handle scenarios
where the page table walk needs to be restarted due to changes in the page
table, such as when a PMD is split. It releases the PTL held during the
previous walk and resets the state, allowing a new walk to start at the
current address stored in pvmw->address.
Link: https://lkml.kernel.org/r/20240610120209.66311-3-ioworker0@xxxxxxxxx
Signed-off-by: Lance Yang <ioworker0@xxxxxxxxx>
Suggested-by: David Hildenbrand <david@xxxxxxxxxx>
Cc: Bang Li <libang.li@xxxxxxxxxxxx>
Cc: Baolin Wang <baolin.wang@xxxxxxxxxxxxxxxxx>
Cc: Fangrui Song <maskray@xxxxxxxxxx>
Cc: Jeff Xie <xiehuan09@xxxxxxxxx>
Cc: Kefeng Wang <wangkefeng.wang@xxxxxxxxxx>
Cc: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxxx>
Cc: Minchan Kim <minchan@xxxxxxxxxx>
Cc: Muchun Song <songmuchun@xxxxxxxxxxxxx>
Cc: Peter Xu <peterx@xxxxxxxxxx>
Cc: Ryan Roberts <ryan.roberts@xxxxxxx>
Cc: SeongJae Park <sj@xxxxxxxxxx>
Cc: Yin Fengwei <fengwei.yin@xxxxxxxxx>
Cc: Zach O'Keefe <zokeefe@xxxxxxxxxx>
Cc: Zi Yan <ziy@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/linux/rmap.h | 22 ++++++++++++++++++++++
1 file changed, 22 insertions(+)
--- a/include/linux/rmap.h~mm-rmap-add-helper-to-restart-pgtable-walk-on-changes
+++ a/include/linux/rmap.h
@@ -703,6 +703,28 @@ static inline void page_vma_mapped_walk_
spin_unlock(pvmw->ptl);
}
+/**
+ * page_vma_mapped_walk_restart - Restart the page table walk.
+ * @pvmw: Pointer to struct page_vma_mapped_walk.
+ *
+ * It restarts the page table walk when changes occur in the page
+ * table, such as splitting a PMD. Ensures that the PTL held during
+ * the previous walk is released and resets the state to allow for
+ * a new walk starting at the current address stored in pvmw->address.
+ */
+static inline void
+page_vma_mapped_walk_restart(struct page_vma_mapped_walk *pvmw)
+{
+ WARN_ON_ONCE(!pvmw->pmd);
+ WARN_ON_ONCE(!pvmw->ptl);
+
+ if (pvmw->ptl)
+ spin_unlock(pvmw->ptl);
+
+ pvmw->ptl = NULL;
+ pvmw->pmd = NULL;
+}
+
bool page_vma_mapped_walk(struct page_vma_mapped_walk *pvmw);
/*
_
Patches currently in -mm which might be from ioworker0@xxxxxxxxx are
mm-rmap-remove-duplicated-exit-code-in-pagewalk-loop.patch
mm-rmap-add-helper-to-restart-pgtable-walk-on-changes.patch
mm-rmap-integrate-pmd-mapped-folio-splitting-into-pagewalk-loop.patch
mm-vmscan-avoid-split-lazyfree-thp-during-shrink_folio_list.patch
