Subject: + mm-rmap-use-rmap_walk-in-try_to_unmap.patch added to -mm tree To: iamjoonsoo.kim@xxxxxxx,dhillf@xxxxxxxxx,hughd@xxxxxxxxxx,mgorman@xxxxxxx,mingo@xxxxxxxxxx,n-horiguchi@xxxxxxxxxxxxx,riel@xxxxxxxxxx From: akpm@xxxxxxxxxxxxxxxxxxxx Date: Wed, 04 Dec 2013 14:16:47 -0800 The patch titled Subject: mm/rmap: use rmap_walk() in try_to_unmap() has been added to the -mm tree. Its filename is mm-rmap-use-rmap_walk-in-try_to_unmap.patch This patch should soon appear at http://ozlabs.org/~akpm/mmots/broken-out/mm-rmap-use-rmap_walk-in-try_to_unmap.patch and later at http://ozlabs.org/~akpm/mmotm/broken-out/mm-rmap-use-rmap_walk-in-try_to_unmap.patch Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/SubmitChecklist when testing your code *** The -mm tree is included into linux-next and is updated there every 3-4 working days ------------------------------------------------------ From: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx> Subject: mm/rmap: use rmap_walk() in try_to_unmap() Now, we have an infrastructure in rmap_walk() to handle difference from variants of rmap traversing functions. So, just use it in try_to_unmap(). In this patch, I change following things. 1. enable rmap_walk() if !CONFIG_MIGRATION. 2. mechanical change to use rmap_walk() in try_to_unmap(). Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx> Reviewed-by: Naoya Horiguchi <n-horiguchi@xxxxxxxxxxxxx> Cc: Mel Gorman <mgorman@xxxxxxx> Cc: Hugh Dickins <hughd@xxxxxxxxxx> Cc: Rik van Riel <riel@xxxxxxxxxx> Cc: Ingo Molnar <mingo@xxxxxxxxxx> Cc: Hillf Danton <dhillf@xxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- include/linux/rmap.h | 5 ---- mm/ksm.c | 4 +-- mm/rmap.c | 48 ++++++++++++++++++++++++++++++----------- 3 files changed, 39 insertions(+), 18 deletions(-) diff -puN include/linux/rmap.h~mm-rmap-use-rmap_walk-in-try_to_unmap include/linux/rmap.h --- a/include/linux/rmap.h~mm-rmap-use-rmap_walk-in-try_to_unmap +++ a/include/linux/rmap.h @@ -190,7 +190,7 @@ int page_referenced_one(struct page *, s int try_to_unmap(struct page *, enum ttu_flags flags); int try_to_unmap_one(struct page *, struct vm_area_struct *, - unsigned long address, enum ttu_flags flags); + unsigned long address, void *arg); /* * Called from mm/filemap_xip.c to unmap empty zero page @@ -256,9 +256,6 @@ struct rmap_walk_control { bool (*invalid_vma)(struct vm_area_struct *vma, void *arg); }; -/* - * Called by migrate.c to remove migration ptes, but might be used more later. - */ int rmap_walk(struct page *page, struct rmap_walk_control *rwc); #else /* !CONFIG_MMU */ diff -puN mm/ksm.c~mm-rmap-use-rmap_walk-in-try_to_unmap mm/ksm.c --- a/mm/ksm.c~mm-rmap-use-rmap_walk-in-try_to_unmap +++ a/mm/ksm.c @@ -1982,7 +1982,7 @@ again: continue; ret = try_to_unmap_one(page, vma, - rmap_item->address, flags); + rmap_item->address, (void *)flags); if (ret != SWAP_AGAIN || !page_mapped(page)) { anon_vma_unlock_read(anon_vma); goto out; @@ -1996,7 +1996,6 @@ out: return ret; } -#ifdef CONFIG_MIGRATION int rmap_walk_ksm(struct page *page, struct rmap_walk_control *rwc) { struct stable_node *stable_node; @@ -2054,6 +2053,7 @@ out: return ret; } +#ifdef CONFIG_MIGRATION void ksm_migrate_page(struct page *newpage, struct page *oldpage) { struct stable_node *stable_node; diff -puN mm/rmap.c~mm-rmap-use-rmap_walk-in-try_to_unmap mm/rmap.c --- a/mm/rmap.c~mm-rmap-use-rmap_walk-in-try_to_unmap +++ a/mm/rmap.c @@ -1175,15 +1175,18 @@ out: /* * Subfunctions of try_to_unmap: try_to_unmap_one called * repeatedly from try_to_unmap_ksm, try_to_unmap_anon or try_to_unmap_file. + * + * @arg: enum ttu_flags will be passed to this argument */ int try_to_unmap_one(struct page *page, struct vm_area_struct *vma, - unsigned long address, enum ttu_flags flags) + unsigned long address, void *arg) { struct mm_struct *mm = vma->vm_mm; pte_t *pte; pte_t pteval; spinlock_t *ptl; int ret = SWAP_AGAIN; + enum ttu_flags flags = (enum ttu_flags)arg; pte = page_check_address(page, mm, address, &ptl, 0); if (!pte) @@ -1509,6 +1512,11 @@ bool is_vma_temporary_stack(struct vm_ar return false; } +static bool invalid_migration_vma(struct vm_area_struct *vma, void *arg) +{ + return is_vma_temporary_stack(vma); +} + /** * try_to_unmap_anon - unmap or unlock anonymous page using the object-based * rmap method @@ -1554,7 +1562,7 @@ static int try_to_unmap_anon(struct page continue; address = vma_address(page, vma); - ret = try_to_unmap_one(page, vma, address, flags); + ret = try_to_unmap_one(page, vma, address, (void *)flags); if (ret != SWAP_AGAIN || !page_mapped(page)) break; } @@ -1588,7 +1596,7 @@ static int try_to_unmap_file(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 = try_to_unmap_one(page, vma, address, flags); + ret = try_to_unmap_one(page, vma, address, (void *)flags); if (ret != SWAP_AGAIN || !page_mapped(page)) goto out; } @@ -1610,6 +1618,11 @@ out: return ret; } +static int page_not_mapped(struct page *page) +{ + return !page_mapped(page); +}; + /** * try_to_unmap - try to remove all page table mappings to a page * @page: the page to get unmapped @@ -1627,16 +1640,29 @@ out: int try_to_unmap(struct page *page, enum ttu_flags flags) { int ret; + struct rmap_walk_control rwc = { + .rmap_one = try_to_unmap_one, + .arg = (void *)flags, + .done = page_not_mapped, + .file_nonlinear = try_to_unmap_nonlinear, + .anon_lock = page_lock_anon_vma_read, + }; - BUG_ON(!PageLocked(page)); VM_BUG_ON(!PageHuge(page) && PageTransHuge(page)); - if (unlikely(PageKsm(page))) - ret = try_to_unmap_ksm(page, flags); - else if (PageAnon(page)) - ret = try_to_unmap_anon(page, flags); - else - ret = try_to_unmap_file(page, flags); + /* + * During exec, a temporary VMA is setup and later moved. + * The VMA is moved under the anon_vma lock but not the + * page tables leading to a race where migration cannot + * find the migration ptes. Rather than increasing the + * locking requirements of exec(), migration skips + * temporary VMAs until after exec() completes. + */ + if (flags & TTU_MIGRATION && !PageKsm(page) && PageAnon(page)) + rwc.invalid_vma = invalid_migration_vma; + + ret = rmap_walk(page, &rwc); + if (ret != SWAP_MLOCK && !page_mapped(page)) ret = SWAP_SUCCESS; return ret; @@ -1679,7 +1705,6 @@ void __put_anon_vma(struct anon_vma *ano anon_vma_free(anon_vma); } -#ifdef CONFIG_MIGRATION static struct anon_vma *rmap_walk_anon_lock(struct page *page, struct rmap_walk_control *rwc) { @@ -1781,7 +1806,6 @@ int rmap_walk(struct page *page, struct else return rmap_walk_file(page, rwc); } -#endif /* CONFIG_MIGRATION */ #ifdef CONFIG_HUGETLB_PAGE /* _ Patches currently in -mm which might be from iamjoonsoo.kim@xxxxxxx are mm-rmap-recompute-pgoff-for-huge-page.patch mm-rmap-factor-nonlinear-handling-out-of-try_to_unmap_file.patch mm-rmap-factor-lock-function-out-of-rmap_walk_anon.patch mm-rmap-make-rmap_walk-to-get-the-rmap_walk_control-argument.patch mm-rmap-extend-rmap_walk_xxx-to-cope-with-different-cases.patch mm-rmap-use-rmap_walk-in-try_to_unmap.patch mm-rmap-use-rmap_walk-in-try_to_munlock.patch mm-rmap-use-rmap_walk-in-page_referenced.patch mm-rmap-use-rmap_walk-in-page_mkclean.patch -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html