On 20 Jul 2024, at 4:11, Kefeng Wang wrote: > On 2024/7/19 22:43, Zi Yan wrote: >> 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. >> >> Reported-by: David Hildenbrand <david@xxxxxxxxxx> >> Closes: https://lore.kernel.org/linux-mm/9af34a6b-ca56-4a64-8aa6-ade65f109288@xxxxxxxxxx/ >> Fixes: 33024536bafd ("memory tiering: hot page selection with hint page fault latency") >> Signed-off-by: Zi Yan <ziy@xxxxxxxxxx> >> Reviewed-by: "Huang, Ying" <ying.huang@xxxxxxxxx> >> Reviewed-by: Baolin Wang <baolin.wang@xxxxxxxxxxxxxxxxx> >> Acked-by: David Hildenbrand <david@xxxxxxxxxx> > > Reviewed-by: Kefeng Wang <wangkefeng.wang@xxxxxxxxxx> > > and we better to check numabalance mode in migrate_misplaced_folio()? > > --- a/mm/migrate.c > +++ b/mm/migrate.c > @@ -2630,7 +2630,8 @@ int migrate_misplaced_folio(struct folio *folio, struct vm_area_struct *vma, > putback_movable_pages(&migratepages); > if (nr_succeeded) { > count_vm_numa_events(NUMA_PAGE_MIGRATE, nr_succeeded); > - if (!node_is_toptier(folio_nid(folio)) && node_is_toptier(node)) > + if ((sysctl_numa_balancing_mode & NUMA_BALANCING_MEMORY_TIERING) > + &&!node_is_toptier(folio_nid(folio)) && node_is_toptier(node)) > mod_node_page_state(pgdat, PGPROMOTE_SUCCESS, > nr_succeeded); > } Yes, will add this as a separate fix. Thanks. -- Best Regards, Yan, Zi
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