The patch titled
Subject: mm/migrate: make migrate_misplaced_folio() return 0 on success
has been added to the -mm mm-unstable branch. Its filename is
mm-migrate-make-migrate_misplaced_folio-return-0-on-success.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-migrate-make-migrate_misplaced_folio-return-0-on-success.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: David Hildenbrand <david@xxxxxxxxxx>
Subject: mm/migrate: make migrate_misplaced_folio() return 0 on success
Date: Thu, 20 Jun 2024 23:29:34 +0200
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@xxxxxxxxxx
Link: https://lkml.kernel.org/r/20240620212935.656243-2-david@xxxxxxxxxx
Signed-off-by: David Hildenbrand <david@xxxxxxxxxx>
Reviewed-by: Zi Yan <ziy@xxxxxxxxxx>
Reviewed-by: Baolin Wang <baolin.wang@xxxxxxxxxxxxxxxxx>
Cc: Donet Tom <donettom@xxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/huge_memory.c | 5 ++---
mm/memory.c | 2 +-
mm/migrate.c | 4 ++--
3 files changed, 5 insertions(+), 6 deletions(-)
--- a/mm/huge_memory.c~mm-migrate-make-migrate_misplaced_folio-return-0-on-success
+++ a/mm/huge_memory.c
@@ -1652,7 +1652,7 @@ vm_fault_t do_huge_pmd_numa_page(struct
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);
@@ -1696,8 +1696,7 @@ vm_fault_t do_huge_pmd_numa_page(struct
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 {
--- a/mm/memory.c~mm-migrate-make-migrate_misplaced_folio-return-0-on-success
+++ a/mm/memory.c
@@ -5354,7 +5354,7 @@ static vm_fault_t do_numa_page(struct vm
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 {
--- a/mm/migrate.c~mm-migrate-make-migrate_misplaced_folio-return-0-on-success
+++ a/mm/migrate.c
@@ -2629,11 +2629,11 @@ int migrate_misplaced_folio(struct folio
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 */
_
Patches currently in -mm which might be from david@xxxxxxxxxx are
mm-memory-move-page_count-check-into-validate_page_before_insert.patch
mm-memory-cleanly-support-zeropage-in-vm_insert_page-vm_map_pages-and-vmf_insert_mixed.patch
mm-rmap-sanity-check-that-zeropages-are-not-passed-to-rmap.patch
fs-proc-task_mmu-indicate-pm_file-for-pmd-mapped-file-thp.patch
fs-proc-task_mmu-dont-indicate-pm_mmap_exclusive-without-pm_present.patch
fs-proc-task_mmu-properly-detect-pm_mmap_exclusive-per-page-of-pmd-mapped-thps.patch
fs-proc-task_mmu-account-non-present-entries-as-maybe-shared-but-no-idea-how-often.patch
fs-proc-move-page_mapcount-to-fs-proc-internalh.patch
documentation-admin-guide-mm-pagemaprst-drop-using-pagemap-to-do-something-useful.patch
mm-pass-meminit_context-to-__free_pages_core.patch
mm-pass-meminit_context-to-__free_pages_core-fix.patch
mm-pass-meminit_context-to-__free_pages_core-fix-2.patch
mm-pass-meminit_context-to-__free_pages_core-fix-3.patch
mm-memory_hotplug-initialize-memmap-of-zone_device-with-pageoffline-instead-of-pagereserved.patch
mm-memory_hotplug-skip-adjust_managed_page_count-for-pageoffline-pages-when-offlining.patch
mm-highmem-reimplement-totalhigh_pages-by-walking-zones.patch
mm-highmem-reimplement-totalhigh_pages-by-walking-zones-fix.patch
mm-highmem-make-nr_free_highpages-return-unsigned-long.patch
mm-read-page_type-using-read_once.patch
mm-migrate-make-migrate_misplaced_folio-return-0-on-success.patch
mm-migrate-move-numa-hinting-fault-folio-isolation-checks-under-ptl.patch
