From: Charan Teja Reddy charante@codeaurora.org

mainline inclusion from mainline-v5.9-rc1 commit de1193f0be66f88e2c6d0fd965137668fc2ec4a5 category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I8GREH CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i...

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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.

Fixes: 1f522509c77a ("mem-hotplug: avoid multiple zones sharing same boot strapping boot_pageset") Signed-off-by: Charan Teja Reddy charante@codeaurora.org Signed-off-by: Andrew Morton akpm@linux-foundation.org Reviewed-by: David Hildenbrand david@redhat.com Acked-by: Vlastimil Babka vbabka@suse.cz Acked-by: Michal Hocko mhocko@suse.com Cc: Vinayak Menon vinmenon@codeaurora.org Link: http://lkml.kernel.org/r/1596372896-15336-1-git-send-email-charante@codeauro... Signed-off-by: Linus Torvalds torvalds@linux-foundation.org Conflicts: mm/memory_hotplug.c Signed-off-by: Liu Shixin liushixin2@huawei.com --- mm/memory_hotplug.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c index 3b961b0fffcc..cebfa881e516 100644 --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c @@ -878,8 +878,7 @@ int __ref online_pages(unsigned long pfn, unsigned long nr_pages, int online_typ 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();