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author | Linus Torvalds <torvalds@linux-foundation.org> | 2013-10-31 15:21:26 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2013-10-31 15:21:26 -0700 |
commit | 52469b4fcd4fc433ffc78cec4cf94368e9052890 (patch) | |
tree | afb4085a30dd4a99a19ea3ebd23b3e3e25814a4e /mm | |
parent | 026f8f612a137324869b6dbdf1d526d176e1766e (diff) | |
parent | 0255d491848032f6c601b6410c3b8ebded3a37b1 (diff) | |
download | linux-52469b4fcd4fc433ffc78cec4cf94368e9052890.tar.bz2 |
Merge branch 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull NUMA balancing memory corruption fixes from Ingo Molnar:
"So these fixes are definitely not something I'd like to sit on, but as
I said to Mel at the KS the timing is quite tight, with Linus planning
v3.12-final within a week.
Fedora-19 is affected:
comet:~> grep NUMA_BALANCING /boot/config-3.11.3-201.fc19.x86_64
CONFIG_ARCH_SUPPORTS_NUMA_BALANCING=y
CONFIG_NUMA_BALANCING_DEFAULT_ENABLED=y
CONFIG_NUMA_BALANCING=y
AFAICS Ubuntu will be affected as well, once it updates the kernel:
hubble:~> grep NUMA_BALANCING /boot/config-3.8.0-32-generic
CONFIG_ARCH_SUPPORTS_NUMA_BALANCING=y
CONFIG_NUMA_BALANCING_DEFAULT_ENABLED=y
CONFIG_NUMA_BALANCING=y
These 6 commits are a minimalized set of cherry-picks needed to fix
the memory corruption bugs. All commits are fixes, except "mm: numa:
Sanitize task_numa_fault() callsites" which is a cleanup that made two
followup fixes simpler.
I've done targeted testing with just this SHA1 to try to make sure
there are no cherry-picking artifacts. The original non-cherry-picked
set of fixes were exposed to linux-next for a couple of weeks"
* 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
mm: Account for a THP NUMA hinting update as one PTE update
mm: Close races between THP migration and PMD numa clearing
mm: numa: Sanitize task_numa_fault() callsites
mm: Prevent parallel splits during THP migration
mm: Wait for THP migrations to complete during NUMA hinting faults
mm: numa: Do not account for a hinting fault if we raced
Diffstat (limited to 'mm')
-rw-r--r-- | mm/huge_memory.c | 70 | ||||
-rw-r--r-- | mm/memory.c | 53 | ||||
-rw-r--r-- | mm/migrate.c | 19 | ||||
-rw-r--r-- | mm/mprotect.c | 2 |
4 files changed, 81 insertions, 63 deletions
diff --git a/mm/huge_memory.c b/mm/huge_memory.c index 610e3df2768a..cca80d96e509 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -1278,64 +1278,90 @@ out: int do_huge_pmd_numa_page(struct mm_struct *mm, struct vm_area_struct *vma, unsigned long addr, pmd_t pmd, pmd_t *pmdp) { + struct anon_vma *anon_vma = NULL; struct page *page; unsigned long haddr = addr & HPAGE_PMD_MASK; + int page_nid = -1, this_nid = numa_node_id(); int target_nid; - int current_nid = -1; - bool migrated; + bool page_locked; + bool migrated = false; spin_lock(&mm->page_table_lock); if (unlikely(!pmd_same(pmd, *pmdp))) goto out_unlock; page = pmd_page(pmd); - get_page(page); - current_nid = page_to_nid(page); + page_nid = page_to_nid(page); count_vm_numa_event(NUMA_HINT_FAULTS); - if (current_nid == numa_node_id()) + if (page_nid == this_nid) count_vm_numa_event(NUMA_HINT_FAULTS_LOCAL); + /* + * Acquire the page lock to serialise THP migrations but avoid dropping + * page_table_lock if at all possible + */ + page_locked = trylock_page(page); target_nid = mpol_misplaced(page, vma, haddr); if (target_nid == -1) { - put_page(page); - goto clear_pmdnuma; + /* If the page was locked, there are no parallel migrations */ + if (page_locked) + goto clear_pmdnuma; + + /* + * Otherwise wait for potential migrations and retry. We do + * relock and check_same as the page may no longer be mapped. + * As the fault is being retried, do not account for it. + */ + spin_unlock(&mm->page_table_lock); + wait_on_page_locked(page); + page_nid = -1; + goto out; } - /* Acquire the page lock to serialise THP migrations */ + /* Page is misplaced, serialise migrations and parallel THP splits */ + get_page(page); spin_unlock(&mm->page_table_lock); - lock_page(page); + if (!page_locked) + lock_page(page); + anon_vma = page_lock_anon_vma_read(page); /* Confirm the PTE did not while locked */ spin_lock(&mm->page_table_lock); if (unlikely(!pmd_same(pmd, *pmdp))) { unlock_page(page); put_page(page); + page_nid = -1; goto out_unlock; } - spin_unlock(&mm->page_table_lock); - /* Migrate the THP to the requested node */ + /* + * Migrate the THP to the requested node, returns with page unlocked + * and pmd_numa cleared. + */ + spin_unlock(&mm->page_table_lock); migrated = migrate_misplaced_transhuge_page(mm, vma, pmdp, pmd, addr, page, target_nid); - if (!migrated) - goto check_same; - - task_numa_fault(target_nid, HPAGE_PMD_NR, true); - return 0; + if (migrated) + page_nid = target_nid; -check_same: - spin_lock(&mm->page_table_lock); - if (unlikely(!pmd_same(pmd, *pmdp))) - goto out_unlock; + goto out; clear_pmdnuma: + BUG_ON(!PageLocked(page)); pmd = pmd_mknonnuma(pmd); set_pmd_at(mm, haddr, pmdp, pmd); VM_BUG_ON(pmd_numa(*pmdp)); update_mmu_cache_pmd(vma, addr, pmdp); + unlock_page(page); out_unlock: spin_unlock(&mm->page_table_lock); - if (current_nid != -1) - task_numa_fault(current_nid, HPAGE_PMD_NR, false); + +out: + if (anon_vma) + page_unlock_anon_vma_read(anon_vma); + + if (page_nid != -1) + task_numa_fault(page_nid, HPAGE_PMD_NR, migrated); + return 0; } diff --git a/mm/memory.c b/mm/memory.c index 1311f26497e6..d176154c243f 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -3521,12 +3521,12 @@ static int do_nonlinear_fault(struct mm_struct *mm, struct vm_area_struct *vma, } int numa_migrate_prep(struct page *page, struct vm_area_struct *vma, - unsigned long addr, int current_nid) + unsigned long addr, int page_nid) { get_page(page); count_vm_numa_event(NUMA_HINT_FAULTS); - if (current_nid == numa_node_id()) + if (page_nid == numa_node_id()) count_vm_numa_event(NUMA_HINT_FAULTS_LOCAL); return mpol_misplaced(page, vma, addr); @@ -3537,7 +3537,7 @@ int do_numa_page(struct mm_struct *mm, struct vm_area_struct *vma, { struct page *page = NULL; spinlock_t *ptl; - int current_nid = -1; + int page_nid = -1; int target_nid; bool migrated = false; @@ -3567,15 +3567,10 @@ int do_numa_page(struct mm_struct *mm, struct vm_area_struct *vma, return 0; } - current_nid = page_to_nid(page); - target_nid = numa_migrate_prep(page, vma, addr, current_nid); + page_nid = page_to_nid(page); + target_nid = numa_migrate_prep(page, vma, addr, page_nid); pte_unmap_unlock(ptep, ptl); if (target_nid == -1) { - /* - * Account for the fault against the current node if it not - * being replaced regardless of where the page is located. - */ - current_nid = numa_node_id(); put_page(page); goto out; } @@ -3583,11 +3578,11 @@ int do_numa_page(struct mm_struct *mm, struct vm_area_struct *vma, /* Migrate to the requested node */ migrated = migrate_misplaced_page(page, target_nid); if (migrated) - current_nid = target_nid; + page_nid = target_nid; out: - if (current_nid != -1) - task_numa_fault(current_nid, 1, migrated); + if (page_nid != -1) + task_numa_fault(page_nid, 1, migrated); return 0; } @@ -3602,7 +3597,6 @@ static int do_pmd_numa_page(struct mm_struct *mm, struct vm_area_struct *vma, unsigned long offset; spinlock_t *ptl; bool numa = false; - int local_nid = numa_node_id(); spin_lock(&mm->page_table_lock); pmd = *pmdp; @@ -3625,9 +3619,10 @@ static int do_pmd_numa_page(struct mm_struct *mm, struct vm_area_struct *vma, for (addr = _addr + offset; addr < _addr + PMD_SIZE; pte++, addr += PAGE_SIZE) { pte_t pteval = *pte; struct page *page; - int curr_nid = local_nid; + int page_nid = -1; int target_nid; - bool migrated; + bool migrated = false; + if (!pte_present(pteval)) continue; if (!pte_numa(pteval)) @@ -3649,25 +3644,19 @@ static int do_pmd_numa_page(struct mm_struct *mm, struct vm_area_struct *vma, if (unlikely(page_mapcount(page) != 1)) continue; - /* - * Note that the NUMA fault is later accounted to either - * the node that is currently running or where the page is - * migrated to. - */ - curr_nid = local_nid; - target_nid = numa_migrate_prep(page, vma, addr, - page_to_nid(page)); - if (target_nid == -1) { + page_nid = page_to_nid(page); + target_nid = numa_migrate_prep(page, vma, addr, page_nid); + pte_unmap_unlock(pte, ptl); + if (target_nid != -1) { + migrated = migrate_misplaced_page(page, target_nid); + if (migrated) + page_nid = target_nid; + } else { put_page(page); - continue; } - /* Migrate to the requested node */ - pte_unmap_unlock(pte, ptl); - migrated = migrate_misplaced_page(page, target_nid); - if (migrated) - curr_nid = target_nid; - task_numa_fault(curr_nid, 1, migrated); + if (page_nid != -1) + task_numa_fault(page_nid, 1, migrated); pte = pte_offset_map_lock(mm, pmdp, addr, &ptl); } diff --git a/mm/migrate.c b/mm/migrate.c index 7a7325ee1d08..c04692774e88 100644 --- a/mm/migrate.c +++ b/mm/migrate.c @@ -1715,12 +1715,12 @@ int migrate_misplaced_transhuge_page(struct mm_struct *mm, unlock_page(new_page); put_page(new_page); /* Free it */ - unlock_page(page); + /* Retake the callers reference and putback on LRU */ + get_page(page); putback_lru_page(page); - - count_vm_events(PGMIGRATE_FAIL, HPAGE_PMD_NR); - isolated = 0; - goto out; + mod_zone_page_state(page_zone(page), + NR_ISOLATED_ANON + page_lru, -HPAGE_PMD_NR); + goto out_fail; } /* @@ -1737,9 +1737,9 @@ int migrate_misplaced_transhuge_page(struct mm_struct *mm, entry = maybe_pmd_mkwrite(pmd_mkdirty(entry), vma); entry = pmd_mkhuge(entry); - page_add_new_anon_rmap(new_page, vma, haddr); - + pmdp_clear_flush(vma, haddr, pmd); set_pmd_at(mm, haddr, pmd, entry); + page_add_new_anon_rmap(new_page, vma, haddr); update_mmu_cache_pmd(vma, address, &entry); page_remove_rmap(page); /* @@ -1758,7 +1758,6 @@ int migrate_misplaced_transhuge_page(struct mm_struct *mm, count_vm_events(PGMIGRATE_SUCCESS, HPAGE_PMD_NR); count_vm_numa_events(NUMA_PAGE_MIGRATE, HPAGE_PMD_NR); -out: mod_zone_page_state(page_zone(page), NR_ISOLATED_ANON + page_lru, -HPAGE_PMD_NR); @@ -1767,6 +1766,10 @@ out: out_fail: count_vm_events(PGMIGRATE_FAIL, HPAGE_PMD_NR); out_dropref: + entry = pmd_mknonnuma(entry); + set_pmd_at(mm, haddr, pmd, entry); + update_mmu_cache_pmd(vma, address, &entry); + unlock_page(page); put_page(page); return 0; diff --git a/mm/mprotect.c b/mm/mprotect.c index a3af058f68e4..412ba2b7326a 100644 --- a/mm/mprotect.c +++ b/mm/mprotect.c @@ -148,7 +148,7 @@ static inline unsigned long change_pmd_range(struct vm_area_struct *vma, split_huge_page_pmd(vma, addr, pmd); else if (change_huge_pmd(vma, pmd, addr, newprot, prot_numa)) { - pages += HPAGE_PMD_NR; + pages++; continue; } /* fall through */ |