From 727d50a7e07259291981b5d84607dc9966def4b1 Mon Sep 17 00:00:00 2001 From: Zi Yan Date: Fri, 9 Aug 2024 10:59:06 -0400 Subject: [PATCH] mm/migrate: move common code to numa_migrate_check (was numa_migrate_prep) 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/20240809145906.1513458-4-ziy@nvidia.com Signed-off-by: Zi Yan Suggested-by: David Hildenbrand Reviewed-by: "Huang, Ying" Reviewed-by: Baolin Wang Acked-by: David Hildenbrand Cc: Baolin Wang Cc: Kefeng Wang Cc: Mel Gorman Cc: Yang Shi Cc: Zi Yan Signed-off-by: Andrew Morton --- mm/huge_memory.c | 29 +++++++++------------- mm/internal.h | 5 ++-- mm/memory.c | 63 +++++++++++++++++++++++++----------------------- 3 files changed, 47 insertions(+), 50 deletions(-) diff --git a/mm/huge_memory.c b/mm/huge_memory.c index 666fa675e5b6..f2fd3aabb67b 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -1669,22 +1669,23 @@ static inline bool can_change_pmd_writable(struct vm_area_struct *vma, 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 @@ -1699,18 +1700,10 @@ vm_fault_t do_huge_pmd_numa_page(struct vm_fault *vmf) 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)) { @@ -1730,13 +1723,13 @@ vm_fault_t do_huge_pmd_numa_page(struct vm_fault *vmf) 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; } 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); diff --git a/mm/internal.h b/mm/internal.h index 1159b04e76a3..a479fe6e1895 100644 --- a/mm/internal.h +++ b/mm/internal.h @@ -1191,8 +1191,9 @@ void vunmap_range_noflush(unsigned long start, unsigned long end); 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); diff --git a/mm/memory.c b/mm/memory.c index 2ca87ceafede..d1c741a39630 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -5200,16 +5200,43 @@ static vm_fault_t do_fault(struct vm_fault *vmf) 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; } @@ -5311,35 +5338,11 @@ static vm_fault_t do_numa_page(struct vm_fault *vmf) 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)) {