6.10-stable review patch. If anyone has any objections, please let me know.
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From: David Hildenbrand david@redhat.com
[ Upstream commit 4b88c23ab8c9bc3857f7c8847e2c6bed95185530 ]
Patch series "mm/migrate: move NUMA hinting fault folio isolation + checks under PTL".
Let's just return 0 on success, which is less confusing.
... especially because we got it wrong in the migrate.h stub where we have "return -EAGAIN; /* can't migrate now */" instead of "return 0;". Likely this wrong return value doesn't currently matter, but it certainly adds confusion.
We'll add migrate_misplaced_folio_prepare() next, where we want to use the same "return 0 on success" approach, so let's just clean this up.
Link: https://lkml.kernel.org/r/20240620212935.656243-1-david@redhat.com Link: https://lkml.kernel.org/r/20240620212935.656243-2-david@redhat.com Signed-off-by: David Hildenbrand david@redhat.com Reviewed-by: Zi Yan ziy@nvidia.com Reviewed-by: Baolin Wang baolin.wang@linux.alibaba.com Cc: Donet Tom donettom@linux.ibm.com Signed-off-by: Andrew Morton akpm@linux-foundation.org Stable-dep-of: 6e49019db5f7 ("mm/migrate: putback split folios when numa hint migration fails") Signed-off-by: Sasha Levin sashal@kernel.org --- mm/huge_memory.c | 5 ++--- mm/memory.c | 2 +- mm/migrate.c | 4 ++-- 3 files changed, 5 insertions(+), 6 deletions(-)
diff --git a/mm/huge_memory.c b/mm/huge_memory.c index e234954cf5067..5ca9d45e6742c 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -1666,7 +1666,7 @@ vm_fault_t do_huge_pmd_numa_page(struct vm_fault *vmf) unsigned long haddr = vmf->address & HPAGE_PMD_MASK; int nid = NUMA_NO_NODE; int target_nid, last_cpupid = (-1 & LAST_CPUPID_MASK); - bool migrated = false, writable = false; + bool writable = false; int flags = 0;
vmf->ptl = pmd_lock(vma->vm_mm, vmf->pmd); @@ -1710,8 +1710,7 @@ vm_fault_t do_huge_pmd_numa_page(struct vm_fault *vmf) spin_unlock(vmf->ptl); writable = false;
- migrated = migrate_misplaced_folio(folio, vma, target_nid); - if (migrated) { + if (!migrate_misplaced_folio(folio, vma, target_nid)) { flags |= TNF_MIGRATED; nid = target_nid; } else { diff --git a/mm/memory.c b/mm/memory.c index f81760c93801f..b1e77b9d17e75 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -5214,7 +5214,7 @@ static vm_fault_t do_numa_page(struct vm_fault *vmf) ignore_writable = true;
/* Migrate to the requested node */ - if (migrate_misplaced_folio(folio, vma, target_nid)) { + if (!migrate_misplaced_folio(folio, vma, target_nid)) { nid = target_nid; flags |= TNF_MIGRATED; } else { diff --git a/mm/migrate.c b/mm/migrate.c index a8c6f466e33ac..83e0e1aa21c7e 100644 --- a/mm/migrate.c +++ b/mm/migrate.c @@ -2656,11 +2656,11 @@ int migrate_misplaced_folio(struct folio *folio, struct vm_area_struct *vma, nr_succeeded); } BUG_ON(!list_empty(&migratepages)); - return isolated; + return isolated ? 0 : -EAGAIN;
out: folio_put(folio); - return 0; + return -EAGAIN; } #endif /* CONFIG_NUMA_BALANCING */ #endif /* CONFIG_NUMA */