+ memory-tiering-count-pgpromote_success-when-mem-tiering-is-enabled.patch added to mm-unstable branch

[Andrew Morton <akpm@linux-foundation.org>]

The patch titled
     Subject: memory tiering: count PGPROMOTE_SUCCESS when mem tiering is enabled.
has been added to the -mm mm-unstable branch.  Its filename is
     memory-tiering-count-pgpromote_success-when-mem-tiering-is-enabled.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/memory-tiering-count-pgpromote_success-when-mem-tiering-is-enabled.patch

This patch will later appear in the mm-unstable branch at
    git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

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------------------------------------------------------
From: Zi Yan <ziy@nvidia.com>
Subject: memory tiering: count PGPROMOTE_SUCCESS when mem tiering is enabled.
Date: Wed, 24 Jul 2024 09:01:15 -0400

memory tiering can be enabled/disabled at runtime and
sysctl_numa_balancing_mode & NUMA_BALANCING_MEMORY_TIERING is used to
check it.  In migrate_misplaced_folio(), the check is missing when
PGPROMOTE_SUCCESS is incremented.  Add the missing check.

Link: https://lkml.kernel.org/r/20240724130115.793641-4-ziy@nvidia.com
Fixes: 33024536bafd ("memory tiering: hot page selection with hint page fault latency")
Reported-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Closes: https://lore.kernel.org/linux-mm/f4ae2c9c-fe40-4807-bdb2-64cf2d716c1a@huawei.com/
Signed-off-by: Zi Yan <ziy@nvidia.com>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/migrate.c |    4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

--- a/mm/migrate.c~memory-tiering-count-pgpromote_success-when-mem-tiering-is-enabled
+++ a/mm/migrate.c
@@ -2630,7 +2630,9 @@ int migrate_misplaced_folio(struct folio
 		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);
 	}
_

Patches currently in -mm which might be from ziy@nvidia.com are

memory-tiering-read-last_cpupid-correctly-in-do_huge_pmd_numa_page.patch
memory-tiering-introduce-folio_use_access_time-check.patch
memory-tiering-count-pgpromote_success-when-mem-tiering-is-enabled.patch