| Message ID | 20240719144306.258018-1-ziy@nvidia.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | [1/2] memory tiering: read last_cpupid correctly in do_huge_pmd_numa_page() | expand |
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@redhat.com> > Closes: https://lore.kernel.org/linux-mm/9af34a6b-ca56-4a64-8aa6-ade65f109288@redhat.com/ > Fixes: 33024536bafd ("memory tiering: hot page selection with hint page fault latency") > Signed-off-by: Zi Yan <ziy@nvidia.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> 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); } > --- > mm/huge_memory.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/mm/huge_memory.c b/mm/huge_memory.c > index f4be468e06a4..825317aee88e 100644 > --- a/mm/huge_memory.c > +++ b/mm/huge_memory.c > @@ -1712,7 +1712,8 @@ vm_fault_t do_huge_pmd_numa_page(struct vm_fault *vmf) > * For memory tiering mode, cpupid of slow memory page is used > * to record page access time. So use default value. > */ > - if (node_is_toptier(nid)) > + if (!(sysctl_numa_balancing_mode & NUMA_BALANCING_MEMORY_TIERING) || > + node_is_toptier(nid)) > last_cpupid = folio_last_cpupid(folio); > target_nid = numa_migrate_prep(folio, vmf, haddr, nid, &flags); > if (target_nid == NUMA_NO_NODE)
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@redhat.com> >> Closes: https://lore.kernel.org/linux-mm/9af34a6b-ca56-4a64-8aa6-ade65f109288@redhat.com/ >> Fixes: 33024536bafd ("memory tiering: hot page selection with hint page fault latency") >> Signed-off-by: Zi Yan <ziy@nvidia.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> > > 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
diff --git a/mm/huge_memory.c b/mm/huge_memory.c index f4be468e06a4..825317aee88e 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -1712,7 +1712,8 @@ vm_fault_t do_huge_pmd_numa_page(struct vm_fault *vmf) * For memory tiering mode, cpupid of slow memory page is used * to record page access time. So use default value. */ - if (node_is_toptier(nid)) + if (!(sysctl_numa_balancing_mode & NUMA_BALANCING_MEMORY_TIERING) || + node_is_toptier(nid)) last_cpupid = folio_last_cpupid(folio); target_nid = numa_migrate_prep(folio, vmf, haddr, nid, &flags); if (target_nid == NUMA_NO_NODE)
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@redhat.com> Closes: https://lore.kernel.org/linux-mm/9af34a6b-ca56-4a64-8aa6-ade65f109288@redhat.com/ Fixes: 33024536bafd ("memory tiering: hot page selection with hint page fault latency") Signed-off-by: Zi Yan <ziy@nvidia.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> --- mm/huge_memory.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)