]> www.infradead.org Git - users/jedix/linux-maple.git/commit
memory tiering: read last_cpupid correctly in do_huge_pmd_numa_page()
authorZi Yan <ziy@nvidia.com>
Wed, 24 Jul 2024 13:01:13 +0000 (09:01 -0400)
committerAndrew Morton <akpm@linux-foundation.org>
Sat, 17 Aug 2024 00:52:26 +0000 (17:52 -0700)
commit362bcfed1c1edb24d07efa8289af0f902e0c7c69
treec54d764c4335bf657db7cfbdc0036f414e3f228d
parent956942c9c2b84eade6a0adbc5f1c00cee7df0ce4
memory tiering: read last_cpupid correctly in do_huge_pmd_numa_page()

Patch series "Various memory tiering fixes", v3.

This patch (of 3):

last_cpupid is only available when memory tiering is off or the folio is
in toptier node.  Complete the check to read last_cpupid when it is
available.

Before the fix, the default last_cpupid will be used even if memory
tiering mode is turned off at runtime instead of the actual value.  This
can prevent task_numa_fault() from getting right numa fault stats, but
should not cause any crash.  User might see performance changes after the
fix.

Link: https://lkml.kernel.org/r/20240724130115.793641-1-ziy@nvidia.com
Link: https://lkml.kernel.org/r/20240724130115.793641-2-ziy@nvidia.com
Fixes: 33024536bafd ("memory tiering: hot page selection with hint page fault latency")
Signed-off-by: Zi Yan <ziy@nvidia.com>
Reported-by: David Hildenbrand <david@redhat.com>
Closes: https://lore.kernel.org/linux-mm/9af34a6b-ca56-4a64-8aa6-ade65f109288@redhat.com/
Reviewed-by: "Huang, Ying" <ying.huang@intel.com>
Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Acked-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
mm/huge_memory.c