The patch titled
Subject: mm, memory_hotplug: update pcp lists everytime onlining a memory block
has been added to the -mm tree. Its filename is
mm-memory_hotplug-update-pcp-lists-everytime-onlining-a-memory-block.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/mm-memory_hotplug-update-pcp-lists-everytime-onlining-a-memory-block.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/mm-memory_hotplug-update-pcp-lists-everytime-onlining-a-memory-block.patch
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------------------------------------------------------
From: Charan Teja Reddy <charante@xxxxxxxxxxxxxx>
Subject: mm, memory_hotplug: update pcp lists everytime onlining a memory block
When onlining a first memory block in a zone, pcp lists are not updated
thus pcp struct will have the default setting of ->high = 0,->batch = 1.
This means till the second memory block in a zone(if it have) is onlined
the pcp lists of this zone will not contain any pages because pcp's
->count is always greater than ->high thus free_pcppages_bulk() is called
to free batch size(=1) pages every time system wants to add a page to the
pcp list through free_unref_page().
To put this in a word, system is not using benefits offered by the pcp
lists when there is a single onlineable memory block in a zone. Correct
this by always updating the pcp lists when memory block is onlined.
Link: http://lkml.kernel.org/r/1596372896-15336-1-git-send-email-charante@xxxxxxxxxxxxxx
Fixes: 1f522509c77a ("mem-hotplug: avoid multiple zones sharing same boot strapping boot_pageset")
Signed-off-by: Charan Teja Reddy <charante@xxxxxxxxxxxxxx>
Reviewed-by: David Hildenbrand <david@xxxxxxxxxx>
Acked-by: Vlastimil Babka <vbabka@xxxxxxx>
Acked-by: Michal Hocko <mhocko@xxxxxxxx>
Cc: Vinayak Menon <vinmenon@xxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/memory_hotplug.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
--- a/mm/memory_hotplug.c~mm-memory_hotplug-update-pcp-lists-everytime-onlining-a-memory-block
+++ a/mm/memory_hotplug.c
@@ -854,8 +854,7 @@ int __ref online_pages(unsigned long pfn
node_states_set_node(nid, &arg);
if (need_zonelists_rebuild)
build_all_zonelists(NULL);
- else
- zone_pcp_update(zone);
+ zone_pcp_update(zone);
init_per_zone_wmark_min();
_
Patches currently in -mm which might be from charante@xxxxxxxxxxxxxx are
mm-page_alloc-skip-waternark_boost-for-atomic-order-0-allocations.patch
mm-page_alloc-skip-watermark_boost-for-atomic-order-0-allocations-fix.patch
mm-memory_hotplug-update-pcp-lists-everytime-onlining-a-memory-block.patch
