The patch titled
Subject: mm/page_alloc: disassociate the pcp->high from pcp->batch -fix
has been added to the -mm tree. Its filename is
mm-page_alloc-disassociate-the-pcp-high-from-pcp-batch-fix.patch
This patch should soon appear at
https://ozlabs.org/~akpm/mmots/broken-out/mm-page_alloc-disassociate-the-pcp-high-from-pcp-batch-fix.patch
and later at
https://ozlabs.org/~akpm/mmotm/broken-out/mm-page_alloc-disassociate-the-pcp-high-from-pcp-batch-fix.patch
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------------------------------------------------------
From: Mel Gorman <mgorman@xxxxxxxxxxxxxxxxxxx>
Subject: mm/page_alloc: disassociate the pcp->high from pcp->batch -fix
Vlastimil Babka noted that __setup_per_zone_wmarks updating pcp->high did
not protect watermark-related sysctl handlers from a parallel memory
hotplug operations. This patch moves the PCP update to
setup_per_zone_wmarks and updates the PCP high value while protected by
the pcp_batch_high_lock mutex.
This is a fix to the mmotm patch
mm-page_alloc-disassociate-the-pcp-high-from-pcp-batch.patch. It'll cause
a conflict with
mm-page_alloc-adjust-pcp-high-after-cpu-hotplug-events.patch but the
resolution is simply to change the caller in setup_per_zone_wmarks to
zone_pcp_update(zone, 0)
Link: https://lkml.kernel.org/r/20210527105241.GB30378@xxxxxxxxxxxxxxxxxxx
Signed-off-by: Mel Gorman <mgorman@xxxxxxxxxxxxxxxxxxx>
Cc: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>
Cc: Hillf Danton <hdanton@xxxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxxxxx>
Cc: Vlastimil Babka <vbabka@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/page_alloc.c | 14 ++++++++------
1 file changed, 8 insertions(+), 6 deletions(-)
--- a/mm/page_alloc.c~mm-page_alloc-disassociate-the-pcp-high-from-pcp-batch-fix
+++ a/mm/page_alloc.c
@@ -8198,12 +8198,6 @@ static void __setup_per_zone_wmarks(void
zone->_watermark[WMARK_LOW] = min_wmark_pages(zone) + tmp;
zone->_watermark[WMARK_HIGH] = min_wmark_pages(zone) + tmp * 2;
- /*
- * The watermark size have changed so update the pcpu batch
- * and high limits or the limits may be inappropriate.
- */
- zone_set_pageset_high_and_batch(zone);
-
spin_unlock_irqrestore(&zone->lock, flags);
}
@@ -8220,11 +8214,19 @@ static void __setup_per_zone_wmarks(void
*/
void setup_per_zone_wmarks(void)
{
+ struct zone *zone;
static DEFINE_SPINLOCK(lock);
spin_lock(&lock);
__setup_per_zone_wmarks();
spin_unlock(&lock);
+
+ /*
+ * The watermark size have changed so update the pcpu batch
+ * and high limits or the limits may be inappropriate.
+ */
+ for_each_zone(zone)
+ zone_pcp_update(zone);
}
/*
_
Patches currently in -mm which might be from mgorman@xxxxxxxxxxxxxxxxxxx are
mm-page_alloc-split-per-cpu-page-lists-and-zone-stats.patch
mm-page_alloc-split-per-cpu-page-lists-and-zone-stats-fix.patch
mm-page_alloc-split-per-cpu-page-lists-and-zone-stats-fix-fix.patch
mm-page_alloc-convert-per-cpu-list-protection-to-local_lock.patch
mm-page_alloc-convert-per-cpu-list-protection-to-local_lock-fix.patch
mm-vmstat-convert-numa-statistics-to-basic-numa-counters.patch
mm-vmstat-inline-numa-event-counter-updates.patch
mm-page_alloc-batch-the-accounting-updates-in-the-bulk-allocator.patch
mm-page_alloc-reduce-duration-that-irqs-are-disabled-for-vm-counters.patch
mm-page_alloc-explicitly-acquire-the-zone-lock-in-__free_pages_ok.patch
mm-page_alloc-avoid-conflating-irqs-disabled-with-zone-lock.patch
mm-page_alloc-update-pgfree-outside-the-zone-lock-in-__free_pages_ok.patch
mm-page_alloc-delete-vmpercpu_pagelist_fraction.patch
mm-page_alloc-disassociate-the-pcp-high-from-pcp-batch.patch
mm-page_alloc-disassociate-the-pcp-high-from-pcp-batch-fix.patch
mm-page_alloc-adjust-pcp-high-after-cpu-hotplug-events.patch
mm-page_alloc-scale-the-number-of-pages-that-are-batch-freed.patch
mm-page_alloc-limit-the-number-of-pages-on-pcp-lists-when-reclaim-is-active.patch
mm-page_alloc-introduce-vmpercpu_pagelist_high_fraction.patch
mm-vmscan-remove-kerneldoc-like-comment-from-isolate_lru_pages.patch
mm-vmalloc-include-header-for-prototype-of-set_iounmap_nonlazy.patch
mm-page_alloc-make-should_fail_alloc_page-a-static-function-should_fail_alloc_page-static.patch
mm-mapping_dirty_helpers-remove-double-note-in-kerneldoc.patch
mm-early_ioremap-add-prototype-for-early_memremap_pgprot_adjust.patch
mm-memcontrolc-fix-kerneldoc-comment-for-mem_cgroup_calculate_protection.patch
mm-memory_hotplug-fix-kerneldoc-comment-for-__try_online_node.patch
mm-memory_hotplug-fix-kerneldoc-comment-for-__remove_memory.patch
mm-zbud-add-kerneldoc-fields-for-zbud_pool.patch
mm-z3fold-add-kerneldoc-fields-for-z3fold_pool.patch
mm-swap-make-swap_address_space-an-inline-function.patch
mm-mmap_lock-remove-dead-code-for-config_tracing-configurations.patch
mm-page_alloc-move-prototype-for-find_suitable_fallback.patch
mm-swap-make-node_data-an-inline-function-on-config_flatmem.patch
