The commit is pushed to "branch-rh7-3.10.0-229.7.2.vz7.9.x-ovz" and will appear at https://src.openvz.org/scm/ovz/vzkernel.git after rh7-3.10.0-229.7.2.vz7.9.15 ------> commit 83bf1997dc0d0556638be25f2570f7d543edb1e6 Author: Vladimir Davydov <vdavy...@virtuozzo.com> Date: Tue Dec 8 18:15:55 2015 +0400
ms/mm/rmap: make rmap_walk to get the rmap_walk_control argument Patchset description: rmap_walk() present in RH7 requires the caller to either hold mmap_sem or pin the page's anon_vma. page_idle_clear_pte_refs does neither. As a result, it might end up trying to lock/unlock anon_vma which has already been freed and possibly reallocated. This won't do any good. Let's pull the new version of rmap_walk() from upstream, which allows to specify a custom anon_vma lock function and use it in page_idle code to avoid this issue. This patch puts page_idle in sync with upstream. I hope this will fix: https://jira.sw.ru/browse/PSBM-42015 Joonsoo Kim (3): mm/rmap: factor lock function out of rmap_walk_anon() mm/rmap: make rmap_walk to get the rmap_walk_control argument mm/rmap: extend rmap_walk_xxx() to cope with different cases Vladimir Davydov (1): mm: page_idle: look up page anon_vma carefully when checking references ============================ This patch description: From: Joonsoo Kim <iamjoonsoo....@lge.com> In each rmap traverse case, there is some difference so that we need function pointers and arguments to them in order to handle these For this purpose, struct rmap_walk_control is introduced in this patch, and will be extended in following patch. Introducing and extending are separate, because it clarify changes. Signed-off-by: Joonsoo Kim <iamjoonsoo....@lge.com> Reviewed-by: Naoya Horiguchi <n-horigu...@ah.jp.nec.com> Cc: Mel Gorman <mgor...@suse.de> Cc: Hugh Dickins <hu...@google.com> Cc: Rik van Riel <r...@redhat.com> Cc: Ingo Molnar <mi...@kernel.org> Cc: Hillf Danton <dhi...@gmail.com> Signed-off-by: Andrew Morton <a...@linux-foundation.org> Signed-off-by: Linus Torvalds <torva...@linux-foundation.org> (cherry picked from commit 051ac83adf69eea4f57a97356e4282e395a5fa6d) Signed-off-by: Vladimir Davydov <vdavy...@virtuozzo.com> --- include/linux/ksm.h | 7 +++---- include/linux/rmap.h | 9 +++++++-- mm/ksm.c | 6 +++--- mm/migrate.c | 7 ++++++- mm/rmap.c | 19 ++++++++----------- 5 files changed, 27 insertions(+), 21 deletions(-) diff --git a/include/linux/ksm.h b/include/linux/ksm.h index 45c9b6a..0eef8cb 100644 --- a/include/linux/ksm.h +++ b/include/linux/ksm.h @@ -76,8 +76,7 @@ struct page *ksm_might_need_to_copy(struct page *page, int page_referenced_ksm(struct page *page, struct mem_cgroup *memcg, unsigned long *vm_flags); int try_to_unmap_ksm(struct page *page, enum ttu_flags flags); -int rmap_walk_ksm(struct page *page, int (*rmap_one)(struct page *, - struct vm_area_struct *, unsigned long, void *), void *arg); +int rmap_walk_ksm(struct page *page, struct rmap_walk_control *rwc); void ksm_migrate_page(struct page *newpage, struct page *oldpage); #else /* !CONFIG_KSM */ @@ -120,8 +119,8 @@ static inline int try_to_unmap_ksm(struct page *page, enum ttu_flags flags) return 0; } -static inline int rmap_walk_ksm(struct page *page, int (*rmap_one)(struct page*, - struct vm_area_struct *, unsigned long, void *), void *arg) +static inline int rmap_walk_ksm(struct page *page, + struct rmap_walk_control *rwc) { return 0; } diff --git a/include/linux/rmap.h b/include/linux/rmap.h index 9775b7b..083b1df 100644 --- a/include/linux/rmap.h +++ b/include/linux/rmap.h @@ -237,11 +237,16 @@ extern struct anon_vma *page_lock_anon_vma_read(struct page *page); extern void page_unlock_anon_vma_read(struct anon_vma *anon_vma); int page_mapped_in_vma(struct page *page, struct vm_area_struct *vma); +struct rmap_walk_control { + void *arg; + int (*rmap_one)(struct page *page, struct vm_area_struct *vma, + unsigned long addr, void *arg); +}; + /* * Called by migrate.c to remove migration ptes, but might be used more later. */ -int rmap_walk(struct page *page, int (*rmap_one)(struct page *, - struct vm_area_struct *, unsigned long, void *), void *arg); +int rmap_walk(struct page *page, struct rmap_walk_control *rwc); #else /* !CONFIG_MMU */ diff --git a/mm/ksm.c b/mm/ksm.c index 74e4c08..ff2d5a3 100644 --- a/mm/ksm.c +++ b/mm/ksm.c @@ -2003,8 +2003,7 @@ out: } #ifdef CONFIG_MIGRATION -int rmap_walk_ksm(struct page *page, int (*rmap_one)(struct page *, - struct vm_area_struct *, unsigned long, void *), void *arg) +int rmap_walk_ksm(struct page *page, struct rmap_walk_control *rwc) { struct stable_node *stable_node; struct rmap_item *rmap_item; @@ -2039,7 +2038,8 @@ again: if ((rmap_item->mm == vma->vm_mm) == search_new_forks) continue; - ret = rmap_one(page, vma, rmap_item->address, arg); + ret = rwc->rmap_one(page, vma, + rmap_item->address, rwc->arg); if (ret != SWAP_AGAIN) { anon_vma_unlock_read(anon_vma); goto out; diff --git a/mm/migrate.c b/mm/migrate.c index c608326..ce9a97c 100644 --- a/mm/migrate.c +++ b/mm/migrate.c @@ -196,7 +196,12 @@ out: */ static void remove_migration_ptes(struct page *old, struct page *new) { - rmap_walk(new, remove_migration_pte, old); + struct rmap_walk_control rwc = { + .rmap_one = remove_migration_pte, + .arg = old, + }; + + rmap_walk(new, &rwc); } /* diff --git a/mm/rmap.c b/mm/rmap.c index df4b9d1..362c5e8 100644 --- a/mm/rmap.c +++ b/mm/rmap.c @@ -1771,8 +1771,7 @@ static struct anon_vma *rmap_walk_anon_lock(struct page *page) * rmap_walk() and its helpers rmap_walk_anon() and rmap_walk_file(): * Called by migrate.c to remove migration ptes, but might be used more later. */ -static int rmap_walk_anon(struct page *page, int (*rmap_one)(struct page *, - struct vm_area_struct *, unsigned long, void *), void *arg) +static int rmap_walk_anon(struct page *page, struct rmap_walk_control *rwc) { struct anon_vma *anon_vma; pgoff_t pgoff = page->index << (PAGE_CACHE_SHIFT - PAGE_SHIFT); @@ -1786,7 +1785,7 @@ static int rmap_walk_anon(struct page *page, int (*rmap_one)(struct page *, anon_vma_interval_tree_foreach(avc, &anon_vma->rb_root, pgoff, pgoff) { struct vm_area_struct *vma = avc->vma; unsigned long address = vma_address(page, vma); - ret = rmap_one(page, vma, address, arg); + ret = rwc->rmap_one(page, vma, address, rwc->arg); if (ret != SWAP_AGAIN) break; } @@ -1794,8 +1793,7 @@ static int rmap_walk_anon(struct page *page, int (*rmap_one)(struct page *, return ret; } -static int rmap_walk_file(struct page *page, int (*rmap_one)(struct page *, - struct vm_area_struct *, unsigned long, void *), void *arg) +static int rmap_walk_file(struct page *page, struct rmap_walk_control *rwc) { struct address_space *mapping = page->mapping; pgoff_t pgoff = page->index << (PAGE_CACHE_SHIFT - PAGE_SHIFT); @@ -1807,7 +1805,7 @@ static int rmap_walk_file(struct page *page, int (*rmap_one)(struct page *, mutex_lock(&mapping->i_mmap_mutex); vma_interval_tree_foreach(vma, &mapping->i_mmap, pgoff, pgoff) { unsigned long address = vma_address(page, vma); - ret = rmap_one(page, vma, address, arg); + ret = rwc->rmap_one(page, vma, address, rwc->arg); if (ret != SWAP_AGAIN) break; } @@ -1820,17 +1818,16 @@ static int rmap_walk_file(struct page *page, int (*rmap_one)(struct page *, return ret; } -int rmap_walk(struct page *page, int (*rmap_one)(struct page *, - struct vm_area_struct *, unsigned long, void *), void *arg) +int rmap_walk(struct page *page, struct rmap_walk_control *rwc) { VM_BUG_ON(!PageLocked(page)); if (unlikely(PageKsm(page))) - return rmap_walk_ksm(page, rmap_one, arg); + return rmap_walk_ksm(page, rwc); else if (PageAnon(page)) - return rmap_walk_anon(page, rmap_one, arg); + return rmap_walk_anon(page, rwc); else - return rmap_walk_file(page, rmap_one, arg); + return rmap_walk_file(page, rwc); } #endif /* CONFIG_MIGRATION */ _______________________________________________ Devel mailing list Devel@openvz.org https://lists.openvz.org/mailman/listinfo/devel