The patch titled
Subject: mm/migrate: move common code to numa_migrate_check (was numa_migrate_prep)
has been added to the -mm mm-unstable branch. Its filename is
mm-migrate-move-common-code-to-numa_migrate_check-was-numa_migrate_prep.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-migrate-move-common-code-to-numa_migrate_check-was-numa_migrate_prep.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@xxxxxxxxxx>
Subject: mm/migrate: move common code to numa_migrate_check (was numa_migrate_prep)
Date: Thu, 8 Aug 2024 19:37:28 -0400
do_numa_page() and do_huge_pmd_numa_page() share a lot of common code. To
reduce redundancy, move common code to numa_migrate_prep() and rename the
function to numa_migrate_check() to reflect its functionality.
Now do_huge_pmd_numa_page() also checks shared folios to set TNF_SHARED
flag.
Link: https://lkml.kernel.org/r/20240808233728.1477034-1-ziy@xxxxxxxxxx
Signed-off-by: Zi Yan <ziy@xxxxxxxxxx>
Suggested-by: David Hildenbrand <david@xxxxxxxxxx>
Cc: Baolin Wang <baolin.wang@xxxxxxxxxxxxxxxxx>
Cc: "Huang, Ying" <ying.huang@xxxxxxxxx>
Cc: Kefeng Wang <wangkefeng.wang@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/huge_memory.c | 29 +++++++-------------
mm/internal.h | 5 ++-
mm/memory.c | 63 +++++++++++++++++++++++----------------------
3 files changed, 47 insertions(+), 50 deletions(-)
--- a/mm/huge_memory.c~mm-migrate-move-common-code-to-numa_migrate_check-was-numa_migrate_prep
+++ a/mm/huge_memory.c
@@ -1753,22 +1753,23 @@ static inline bool can_change_pmd_writab
vm_fault_t do_huge_pmd_numa_page(struct vm_fault *vmf)
{
struct vm_area_struct *vma = vmf->vma;
- pmd_t oldpmd = vmf->orig_pmd;
- pmd_t pmd;
struct folio *folio;
unsigned long haddr = vmf->address & HPAGE_PMD_MASK;
int nid = NUMA_NO_NODE;
- int target_nid, last_cpupid = (-1 & LAST_CPUPID_MASK);
+ int target_nid, last_cpupid;
+ pmd_t pmd, old_pmd;
bool writable = false;
int flags = 0;
vmf->ptl = pmd_lock(vma->vm_mm, vmf->pmd);
- if (unlikely(!pmd_same(oldpmd, *vmf->pmd))) {
+ old_pmd = pmdp_get(vmf->pmd);
+
+ if (unlikely(!pmd_same(old_pmd, vmf->orig_pmd))) {
spin_unlock(vmf->ptl);
return 0;
}
- pmd = pmd_modify(oldpmd, vma->vm_page_prot);
+ pmd = pmd_modify(old_pmd, vma->vm_page_prot);
/*
* Detect now whether the PMD could be writable; this information
@@ -1783,18 +1784,10 @@ vm_fault_t do_huge_pmd_numa_page(struct
if (!folio)
goto out_map;
- /* See similar comment in do_numa_page for explanation */
- if (!writable)
- flags |= TNF_NO_GROUP;
-
nid = folio_nid(folio);
- /*
- * For memory tiering mode, cpupid of slow memory page is used
- * to record page access time. So use default value.
- */
- if (!folio_use_access_time(folio))
- last_cpupid = folio_last_cpupid(folio);
- target_nid = numa_migrate_prep(folio, vmf, haddr, nid, &flags);
+
+ target_nid = numa_migrate_check(folio, vmf, haddr, &flags, writable,
+ &last_cpupid);
if (target_nid == NUMA_NO_NODE)
goto out_map;
if (migrate_misplaced_folio_prepare(folio, vma, target_nid)) {
@@ -1812,7 +1805,7 @@ vm_fault_t do_huge_pmd_numa_page(struct
} else {
flags |= TNF_MIGRATE_FAIL;
vmf->ptl = pmd_lock(vma->vm_mm, vmf->pmd);
- if (unlikely(!pmd_same(oldpmd, *vmf->pmd))) {
+ if (unlikely(!pmd_same(pmdp_get(vmf->pmd), vmf->orig_pmd))) {
spin_unlock(vmf->ptl);
return 0;
}
@@ -1820,7 +1813,7 @@ vm_fault_t do_huge_pmd_numa_page(struct
out_map:
/* Restore the PMD */
- pmd = pmd_modify(oldpmd, vma->vm_page_prot);
+ pmd = pmd_modify(pmdp_get(vmf->pmd), vma->vm_page_prot);
pmd = pmd_mkyoung(pmd);
if (writable)
pmd = pmd_mkwrite(pmd, vma);
--- a/mm/internal.h~mm-migrate-move-common-code-to-numa_migrate_check-was-numa_migrate_prep
+++ a/mm/internal.h
@@ -1191,8 +1191,9 @@ void vunmap_range_noflush(unsigned long
void __vunmap_range_noflush(unsigned long start, unsigned long end);
-int numa_migrate_prep(struct folio *folio, struct vm_fault *vmf,
- unsigned long addr, int page_nid, int *flags);
+int numa_migrate_check(struct folio *folio, struct vm_fault *vmf,
+ unsigned long addr, int *flags, bool writable,
+ int *last_cpupid);
void free_zone_device_folio(struct folio *folio);
int migrate_device_coherent_page(struct page *page);
--- a/mm/memory.c~mm-migrate-move-common-code-to-numa_migrate_check-was-numa_migrate_prep
+++ a/mm/memory.c
@@ -5364,16 +5364,43 @@ static vm_fault_t do_fault(struct vm_fau
return ret;
}
-int numa_migrate_prep(struct folio *folio, struct vm_fault *vmf,
- unsigned long addr, int page_nid, int *flags)
+int numa_migrate_check(struct folio *folio, struct vm_fault *vmf,
+ unsigned long addr, int *flags,
+ bool writable, int *last_cpupid)
{
struct vm_area_struct *vma = vmf->vma;
+ /*
+ * Avoid grouping on RO pages in general. RO pages shouldn't hurt as
+ * much anyway since they can be in shared cache state. This misses
+ * the case where a mapping is writable but the process never writes
+ * to it but pte_write gets cleared during protection updates and
+ * pte_dirty has unpredictable behaviour between PTE scan updates,
+ * background writeback, dirty balancing and application behaviour.
+ */
+ if (!writable)
+ *flags |= TNF_NO_GROUP;
+
+ /*
+ * Flag if the folio is shared between multiple address spaces. This
+ * is later used when determining whether to group tasks together
+ */
+ if (folio_likely_mapped_shared(folio) && (vma->vm_flags & VM_SHARED))
+ *flags |= TNF_SHARED;
+ /*
+ * For memory tiering mode, cpupid of slow memory page is used
+ * to record page access time. So use default value.
+ */
+ if (folio_use_access_time(folio))
+ *last_cpupid = (-1 & LAST_CPUPID_MASK);
+ else
+ *last_cpupid = folio_last_cpupid(folio);
+
/* Record the current PID acceesing VMA */
vma_set_access_pid_bit(vma);
count_vm_numa_event(NUMA_HINT_FAULTS);
- if (page_nid == numa_node_id()) {
+ if (folio_nid(folio) == numa_node_id()) {
count_vm_numa_event(NUMA_HINT_FAULTS_LOCAL);
*flags |= TNF_FAULT_LOCAL;
}
@@ -5475,35 +5502,11 @@ static vm_fault_t do_numa_page(struct vm
if (!folio || folio_is_zone_device(folio))
goto out_map;
- /*
- * Avoid grouping on RO pages in general. RO pages shouldn't hurt as
- * much anyway since they can be in shared cache state. This misses
- * the case where a mapping is writable but the process never writes
- * to it but pte_write gets cleared during protection updates and
- * pte_dirty has unpredictable behaviour between PTE scan updates,
- * background writeback, dirty balancing and application behaviour.
- */
- if (!writable)
- flags |= TNF_NO_GROUP;
-
- /*
- * Flag if the folio is shared between multiple address spaces. This
- * is later used when determining whether to group tasks together
- */
- if (folio_likely_mapped_shared(folio) && (vma->vm_flags & VM_SHARED))
- flags |= TNF_SHARED;
-
nid = folio_nid(folio);
nr_pages = folio_nr_pages(folio);
- /*
- * For memory tiering mode, cpupid of slow memory page is used
- * to record page access time. So use default value.
- */
- if (folio_use_access_time(folio))
- last_cpupid = (-1 & LAST_CPUPID_MASK);
- else
- last_cpupid = folio_last_cpupid(folio);
- target_nid = numa_migrate_prep(folio, vmf, vmf->address, nid, &flags);
+
+ target_nid = numa_migrate_check(folio, vmf, vmf->address, &flags,
+ writable, &last_cpupid);
if (target_nid == NUMA_NO_NODE)
goto out_map;
if (migrate_misplaced_folio_prepare(folio, vma, target_nid)) {
_
Patches currently in -mm which might be from ziy@xxxxxxxxxx are
mm-numa-no-task_numa_fault-call-if-page-table-is-changed.patch
mm-numa-no-task_numa_fault-call-if-page-table-is-changed-fix.patch
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
mm-migrate-move-common-code-to-numa_migrate_check-was-numa_migrate_prep.patch
