The patch titled
Subject: mm-memory-failure-fix-deadlock-when-hugetlb_optimize_vmemmap-is-enabled-v2-fix
has been added to the -mm mm-hotfixes-unstable branch. Its filename is
mm-memory-failure-fix-deadlock-when-hugetlb_optimize_vmemmap-is-enabled-v2-fix.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-memory-failure-fix-deadlock-when-hugetlb_optimize_vmemmap-is-enabled-v2-fix.patch
This patch will later appear in the mm-hotfixes-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: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Subject: mm-memory-failure-fix-deadlock-when-hugetlb_optimize_vmemmap-is-enabled-v2-fix
Date: Fri Apr 12 04:18:11 PM PDT 2024
reflow block comment
Cc: Miaohe Lin <linmiaohe@xxxxxxxxxx>
Cc: Oscar Salvador <osalvador@xxxxxxx>
Cc: Naoya Horiguchi <nao.horiguchi@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/memory-failure.c | 18 ++++++++++--------
1 file changed, 10 insertions(+), 8 deletions(-)
--- a/mm/memory-failure.c~mm-memory-failure-fix-deadlock-when-hugetlb_optimize_vmemmap-is-enabled-v2-fix
+++ a/mm/memory-failure.c
@@ -155,14 +155,16 @@ static int __page_handle_poison(struct p
int ret;
/*
- * zone_pcp_disable() can't be used here. It will hold pcp_batch_high_lock and
- * dissolve_free_huge_page() might hold cpu_hotplug_lock via static_key_slow_dec()
- * when hugetlb vmemmap optimization is enabled. This will break current lock
- * dependency chain and leads to deadlock.
- * Disabling pcp before dissolving the page was a deterministic approach because
- * we made sure that those pages cannot end up in any PCP list. Draining PCP lists
- * expels those pages to the buddy system, but nothing guarantees that those pages
- * do not get back to a PCP queue if we need to refill those.
+ * zone_pcp_disable() can't be used here. It will
+ * hold pcp_batch_high_lock and dissolve_free_huge_page() might hold
+ * cpu_hotplug_lock via static_key_slow_dec() when hugetlb vmemmap
+ * optimization is enabled. This will break current lock dependency
+ * chain and leads to deadlock.
+ * Disabling pcp before dissolving the page was a deterministic
+ * approach because we made sure that those pages cannot end up in any
+ * PCP list. Draining PCP lists expels those pages to the buddy system,
+ * but nothing guarantees that those pages do not get back to a PCP
+ * queue if we need to refill those.
*/
ret = dissolve_free_huge_page(page);
if (!ret) {
_
Patches currently in -mm which might be from akpm@xxxxxxxxxxxxxxxxxxxx are
mm-memory-failure-fix-deadlock-when-hugetlb_optimize_vmemmap-is-enabled-v2-fix.patch
selftests-harness-remove-use-of-line_max-fix.patch
mm-sparc-change-pxd_huge-behavior-to-exclude-swap-entries-fix.patch
mm-hold-ptl-from-the-first-pte-while-reclaiming-a-large-folio-fix.patch
sh-remove-use-of-pg_arch_1-on-individual-pages-fix.patch
mm-gup-drop-folio_fast_pin_allowed-in-hugepd-processing-fix.patch
mm-allow-anon-exclusive-check-over-hugetlb-tail-pages-fix.patch
arm-mm-drop-vm_fault_badmap-vm_fault_badaccess-checkpatch-fixes.patch
__mod_memcg_lruvec_state-enhance-diagnostics.patch
__mod_memcg_lruvec_state-enhance-diagnostics-fix.patch
