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/[email protected]
Link: https://lkml.kernel.org/r/[email protected]
Fixes: 33024536bafd ("memory tiering: hot page selection with hint page fault latency")
Signed-off-by: Zi Yan <[email protected]>
Reported-by: David Hildenbrand <[email protected]>
Closes: https://lore.kernel.org/linux-mm/[email protected]/
Reviewed-by: "Huang, Ying" <[email protected]>
Reviewed-by: Baolin Wang <[email protected]>
Acked-by: David Hildenbrand <[email protected]>
Reviewed-by: Kefeng Wang <[email protected]>
Cc: Lorenzo Stoakes <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

0 files changed, 0 insertions, 0 deletions