The patch titled
Subject: hugetlb: clarify hugetlb_instantiation_mutex usage
has been added to the -mm tree. Its filename is
hugetlb-clarify-hugetlb_instantiation_mutex-usage.patch
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------------------------------------------------------
From: Michal Hocko <mhocko@xxxxxxx>
Subject: hugetlb: clarify hugetlb_instantiation_mutex usage
Let's make it clear that we cannot race with other fault handlers due to
hugetlb (global) mutex. Also make it clear that we want to keep pte_same
checks anayway to have a transition from the global mutex easier.
Signed-off-by: Michal Hocko <mhocko@xxxxxxx>
Cc: Hillf Danton <dhillf@xxxxxxxxx>
Cc: Andrea Arcangeli <aarcange@xxxxxxxxxx>
Cc: Johannes Weiner <jweiner@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/hugetlb.c | 3 +++
1 file changed, 3 insertions(+)
diff -puN mm/hugetlb.c~hugetlb-clarify-hugetlb_instantiation_mutex-usage mm/hugetlb.c
--- a/mm/hugetlb.c~hugetlb-clarify-hugetlb_instantiation_mutex-usage
+++ a/mm/hugetlb.c
@@ -2348,6 +2348,9 @@ static int unmap_ref_private(struct mm_s
/*
* Hugetlb_cow() should be called with page lock of the original hugepage held.
+ * Called with hugetlb_instantiation_mutex held and pte_page locked so we
+ * cannot race with other handlers or page migration.
+ * Keep the pte_same checks anyway to make transition from the mutex easier.
*/
static int hugetlb_cow(struct mm_struct *mm, struct vm_area_struct *vma,
unsigned long address, pte_t *ptep, pte_t pte,
_
Subject: Subject: hugetlb: clarify hugetlb_instantiation_mutex usage
Patches currently in -mm which might be from mhocko@xxxxxxx are
origin.patch
linux-next.patch
mm-page-writebackc-make-determine_dirtyable_memory-static-again.patch
hugetlb-detect-race-upon-page-allocation-failure-during-cow.patch
hugetlb-clarify-hugetlb_instantiation_mutex-usage.patch
cgroup_freezer-fix-freezing-groups-with-stopped-tasks.patch
mm-memcg-consolidate-hierarchy-iteration-primitives.patch
mm-vmscan-distinguish-global-reclaim-from-global-lru-scanning.patch
mm-vmscan-distinguish-between-memcg-triggering-reclaim-and-memcg-being-scanned.patch
mm-memcg-per-priority-per-zone-hierarchy-scan-generations.patch
mm-move-memcg-hierarchy-reclaim-to-generic-reclaim-code.patch
mm-memcg-remove-optimization-of-keeping-the-root_mem_cgroup-lru-lists-empty.patch
mm-vmscan-convert-global-reclaim-to-per-memcg-lru-lists.patch
mm-collect-lru-list-heads-into-struct-lruvec.patch
mm-make-per-memcg-lru-lists-exclusive.patch
mm-memcg-remove-unused-node-section-info-from-pc-flags.patch
mm-memcg-remove-unused-node-section-info-from-pc-flags-fix.patch
memcg-make-mem_cgroup_split_huge_fixup-more-efficient.patch
memcg-make-mem_cgroup_split_huge_fixup-more-efficient-fix.patch
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