The patch titled
Subject: mm-page_alloc-disable-pcplists-during-memory-offline-fix
has been added to the -mm tree. Its filename is
mm-page_alloc-disable-pcplists-during-memory-offline-fix.patch
This patch should soon appear at
https://ozlabs.org/~akpm/mmots/broken-out/mm-page_alloc-disable-pcplists-during-memory-offline-fix.patch
and later at
https://ozlabs.org/~akpm/mmotm/broken-out/mm-page_alloc-disable-pcplists-during-memory-offline-fix.patch
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------------------------------------------------------
From: Vlastimil Babka <vbabka@xxxxxxx>
Subject: mm-page_alloc-disable-pcplists-during-memory-offline-fix
add comment, per David
Link: https://lkml.kernel.org/r/527480ef-ed72-e1c1-52a0-1c5b0113df45@xxxxxxx
Signed-off-by: Vlastimil Babka <vbabka@xxxxxxx>
Cc: David Hildenbrand <david@xxxxxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxxx>
Cc: Oscar Salvador <osalvador@xxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/page_alloc.c | 10 ++++++++++
1 file changed, 10 insertions(+)
--- a/mm/page_alloc.c~mm-page_alloc-disable-pcplists-during-memory-offline-fix
+++ a/mm/page_alloc.c
@@ -3024,6 +3024,16 @@ static void drain_local_pages_wq(struct
preempt_enable();
}
+/*
+ * The implementation of drain_all_pages(), exposing an extra parameter to
+ * drain on all cpus.
+ *
+ * drain_all_pages() is optimized to only execute on cpus where pcplists are
+ * not empty. The check for non-emptiness can however race with a free to
+ * pcplist that has not yet increased the pcp->count from 0 to 1. Callers
+ * that need the guarantee that every CPU has drained can disable the
+ * optimizing racy check.
+ */
void __drain_all_pages(struct zone *zone, bool force_all_cpus)
{
int cpu;
_
Patches currently in -mm which might be from vbabka@xxxxxxx are
mm-slub-use-kmem_cache_debug_flags-in-deactivate_slab.patch
mm-page_alloc-clean-up-pageset-high-and-batch-update.patch
mm-page_alloc-calculate-pageset-high-and-batch-once-per-zone.patch
mm-page_alloc-remove-setup_pageset.patch
mm-page_alloc-simplify-pageset_update.patch
mm-page_alloc-cache-pageset-high-and-batch-in-struct-zone.patch
mm-page_alloc-move-draining-pcplists-to-page-isolation-users.patch
mm-page_alloc-disable-pcplists-during-memory-offline.patch
mm-page_alloc-disable-pcplists-during-memory-offline-fix.patch
