From: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> To: Andrew Morton <akpm@linux-foundation.org>, Andrea Arcangeli <aarcange@redhat.com>, Hugh Dickins <hughd@google.com> Cc: Dave Hansen <dave.hansen@intel.com>, Mel Gorman <mgorman@suse.de>, Rik van Riel <riel@redhat.com>, Vlastimil Babka <vbabka@suse.cz>, Christoph Lameter <cl@gentwo.org>, Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>, Steve Capper <steve.capper@linaro.org>, "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>, Johannes Weiner <hannes@cmpxchg.org>, Michal Hocko <mhocko@suse.cz>, Jerome Marchand <jmarchan@redhat.com>, Sasha Levin <sasha.levin@oracle.com>, linux-kernel@vger.kernel.org, linux-mm@kvack.org, "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Subject: [PATCHv6 07/36] thp, mlock: do not allow huge pages in mlocked area Date: Wed, 3 Jun 2015 20:05:38 +0300 [thread overview] Message-ID: <1433351167-125878-8-git-send-email-kirill.shutemov@linux.intel.com> (raw) In-Reply-To: <1433351167-125878-1-git-send-email-kirill.shutemov@linux.intel.com> With new refcounting THP can belong to several VMAs. This makes tricky to track THP pages, when they partially mlocked. It can lead to leaking mlocked pages to non-VM_LOCKED vmas and other problems. With this patch we will split all pages on mlock and avoid fault-in/collapse new THP in VM_LOCKED vmas. I've tried alternative approach: do not mark THP pages mlocked and keep them on normal LRUs. This way vmscan could try to split huge pages on memory pressure and free up subpages which doesn't belong to VM_LOCKED vmas. But this is user-visible change: we screw up Mlocked accouting reported in meminfo, so I had to leave this approach aside. We can bring something better later, but this should be good enough for now. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Tested-by: Sasha Levin <sasha.levin@oracle.com> Acked-by: Jerome Marchand <jmarchan@redhat.com> --- mm/gup.c | 2 ++ mm/huge_memory.c | 5 ++++- mm/memory.c | 3 ++- mm/mlock.c | 51 +++++++++++++++++++-------------------------------- 4 files changed, 27 insertions(+), 34 deletions(-) diff --git a/mm/gup.c b/mm/gup.c index d975bdc2465f..2c2fa62f54f0 100644 --- a/mm/gup.c +++ b/mm/gup.c @@ -882,6 +882,8 @@ long populate_vma_page_range(struct vm_area_struct *vma, VM_BUG_ON_MM(!rwsem_is_locked(&mm->mmap_sem), mm); gup_flags = FOLL_TOUCH | FOLL_POPULATE; + if (vma->vm_flags & VM_LOCKED) + gup_flags |= FOLL_SPLIT; /* * We want to touch writable mappings with a write fault in order * to break COW, except for shared mappings because these don't COW diff --git a/mm/huge_memory.c b/mm/huge_memory.c index 6035cc92be6b..4ad975506c1b 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -815,6 +815,8 @@ int do_huge_pmd_anonymous_page(struct mm_struct *mm, struct vm_area_struct *vma, if (haddr < vma->vm_start || haddr + HPAGE_PMD_SIZE > vma->vm_end) return VM_FAULT_FALLBACK; + if (vma->vm_flags & VM_LOCKED) + return VM_FAULT_FALLBACK; if (unlikely(anon_vma_prepare(vma))) return VM_FAULT_OOM; if (unlikely(khugepaged_enter(vma, vma->vm_flags))) @@ -2493,7 +2495,8 @@ static bool hugepage_vma_check(struct vm_area_struct *vma) if ((!(vma->vm_flags & VM_HUGEPAGE) && !khugepaged_always()) || (vma->vm_flags & VM_NOHUGEPAGE)) return false; - + if (vma->vm_flags & VM_LOCKED) + return false; if (!vma->anon_vma || vma->vm_ops) return false; if (is_vma_temporary_stack(vma)) diff --git a/mm/memory.c b/mm/memory.c index f48dfa6d8859..8067c47ecf14 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -2161,7 +2161,8 @@ static int wp_page_copy(struct mm_struct *mm, struct vm_area_struct *vma, pte_unmap_unlock(page_table, ptl); mmu_notifier_invalidate_range_end(mm, mmun_start, mmun_end); - if (old_page) { + /* THP pages are never mlocked */ + if (old_page && !PageTransCompound(old_page)) { /* * Don't let another task, with possibly unlocked vma, * keep the mlocked page. diff --git a/mm/mlock.c b/mm/mlock.c index 25936680064f..1d47b98407de 100644 --- a/mm/mlock.c +++ b/mm/mlock.c @@ -443,39 +443,26 @@ void munlock_vma_pages_range(struct vm_area_struct *vma, page = follow_page_mask(vma, start, FOLL_GET | FOLL_DUMP, &page_mask); - if (page && !IS_ERR(page)) { - if (PageTransHuge(page)) { - lock_page(page); - /* - * Any THP page found by follow_page_mask() may - * have gotten split before reaching - * munlock_vma_page(), so we need to recompute - * the page_mask here. - */ - page_mask = munlock_vma_page(page); - unlock_page(page); - put_page(page); /* follow_page_mask() */ - } else { - /* - * Non-huge pages are handled in batches via - * pagevec. The pin from follow_page_mask() - * prevents them from collapsing by THP. - */ - pagevec_add(&pvec, page); - zone = page_zone(page); - zoneid = page_zone_id(page); + if (page && !IS_ERR(page) && !PageTransCompound(page)) { + /* + * Non-huge pages are handled in batches via + * pagevec. The pin from follow_page_mask() + * prevents them from collapsing by THP. + */ + pagevec_add(&pvec, page); + zone = page_zone(page); + zoneid = page_zone_id(page); - /* - * Try to fill the rest of pagevec using fast - * pte walk. This will also update start to - * the next page to process. Then munlock the - * pagevec. - */ - start = __munlock_pagevec_fill(&pvec, vma, - zoneid, start, end); - __munlock_pagevec(&pvec, zone); - goto next; - } + /* + * Try to fill the rest of pagevec using fast + * pte walk. This will also update start to + * the next page to process. Then munlock the + * pagevec. + */ + start = __munlock_pagevec_fill(&pvec, vma, + zoneid, start, end); + __munlock_pagevec(&pvec, zone); + goto next; } /* It's a bug to munlock in the middle of a THP page */ VM_BUG_ON((start >> PAGE_SHIFT) & page_mask); -- 2.1.4
WARNING: multiple messages have this Message-ID (diff)
From: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> To: Andrew Morton <akpm@linux-foundation.org>, Andrea Arcangeli <aarcange@redhat.com>, Hugh Dickins <hughd@google.com> Cc: Dave Hansen <dave.hansen@intel.com>, Mel Gorman <mgorman@suse.de>, Rik van Riel <riel@redhat.com>, Vlastimil Babka <vbabka@suse.cz>, Christoph Lameter <cl@gentwo.org>, Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>, Steve Capper <steve.capper@linaro.org>, "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>, Johannes Weiner <hannes@cmpxchg.org>, Michal Hocko <mhocko@suse.cz>, Jerome Marchand <jmarchan@redhat.com>, Sasha Levin <sasha.levin@oracle.com>, linux-kernel@vger.kernel.org, linux-mm@kvack.org, "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Subject: [PATCHv6 07/36] thp, mlock: do not allow huge pages in mlocked area Date: Wed, 3 Jun 2015 20:05:38 +0300 [thread overview] Message-ID: <1433351167-125878-8-git-send-email-kirill.shutemov@linux.intel.com> (raw) In-Reply-To: <1433351167-125878-1-git-send-email-kirill.shutemov@linux.intel.com> With new refcounting THP can belong to several VMAs. This makes tricky to track THP pages, when they partially mlocked. It can lead to leaking mlocked pages to non-VM_LOCKED vmas and other problems. With this patch we will split all pages on mlock and avoid fault-in/collapse new THP in VM_LOCKED vmas. I've tried alternative approach: do not mark THP pages mlocked and keep them on normal LRUs. This way vmscan could try to split huge pages on memory pressure and free up subpages which doesn't belong to VM_LOCKED vmas. But this is user-visible change: we screw up Mlocked accouting reported in meminfo, so I had to leave this approach aside. We can bring something better later, but this should be good enough for now. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Tested-by: Sasha Levin <sasha.levin@oracle.com> Acked-by: Jerome Marchand <jmarchan@redhat.com> --- mm/gup.c | 2 ++ mm/huge_memory.c | 5 ++++- mm/memory.c | 3 ++- mm/mlock.c | 51 +++++++++++++++++++-------------------------------- 4 files changed, 27 insertions(+), 34 deletions(-) diff --git a/mm/gup.c b/mm/gup.c index d975bdc2465f..2c2fa62f54f0 100644 --- a/mm/gup.c +++ b/mm/gup.c @@ -882,6 +882,8 @@ long populate_vma_page_range(struct vm_area_struct *vma, VM_BUG_ON_MM(!rwsem_is_locked(&mm->mmap_sem), mm); gup_flags = FOLL_TOUCH | FOLL_POPULATE; + if (vma->vm_flags & VM_LOCKED) + gup_flags |= FOLL_SPLIT; /* * We want to touch writable mappings with a write fault in order * to break COW, except for shared mappings because these don't COW diff --git a/mm/huge_memory.c b/mm/huge_memory.c index 6035cc92be6b..4ad975506c1b 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -815,6 +815,8 @@ int do_huge_pmd_anonymous_page(struct mm_struct *mm, struct vm_area_struct *vma, if (haddr < vma->vm_start || haddr + HPAGE_PMD_SIZE > vma->vm_end) return VM_FAULT_FALLBACK; + if (vma->vm_flags & VM_LOCKED) + return VM_FAULT_FALLBACK; if (unlikely(anon_vma_prepare(vma))) return VM_FAULT_OOM; if (unlikely(khugepaged_enter(vma, vma->vm_flags))) @@ -2493,7 +2495,8 @@ static bool hugepage_vma_check(struct vm_area_struct *vma) if ((!(vma->vm_flags & VM_HUGEPAGE) && !khugepaged_always()) || (vma->vm_flags & VM_NOHUGEPAGE)) return false; - + if (vma->vm_flags & VM_LOCKED) + return false; if (!vma->anon_vma || vma->vm_ops) return false; if (is_vma_temporary_stack(vma)) diff --git a/mm/memory.c b/mm/memory.c index f48dfa6d8859..8067c47ecf14 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -2161,7 +2161,8 @@ static int wp_page_copy(struct mm_struct *mm, struct vm_area_struct *vma, pte_unmap_unlock(page_table, ptl); mmu_notifier_invalidate_range_end(mm, mmun_start, mmun_end); - if (old_page) { + /* THP pages are never mlocked */ + if (old_page && !PageTransCompound(old_page)) { /* * Don't let another task, with possibly unlocked vma, * keep the mlocked page. diff --git a/mm/mlock.c b/mm/mlock.c index 25936680064f..1d47b98407de 100644 --- a/mm/mlock.c +++ b/mm/mlock.c @@ -443,39 +443,26 @@ void munlock_vma_pages_range(struct vm_area_struct *vma, page = follow_page_mask(vma, start, FOLL_GET | FOLL_DUMP, &page_mask); - if (page && !IS_ERR(page)) { - if (PageTransHuge(page)) { - lock_page(page); - /* - * Any THP page found by follow_page_mask() may - * have gotten split before reaching - * munlock_vma_page(), so we need to recompute - * the page_mask here. - */ - page_mask = munlock_vma_page(page); - unlock_page(page); - put_page(page); /* follow_page_mask() */ - } else { - /* - * Non-huge pages are handled in batches via - * pagevec. The pin from follow_page_mask() - * prevents them from collapsing by THP. - */ - pagevec_add(&pvec, page); - zone = page_zone(page); - zoneid = page_zone_id(page); + if (page && !IS_ERR(page) && !PageTransCompound(page)) { + /* + * Non-huge pages are handled in batches via + * pagevec. The pin from follow_page_mask() + * prevents them from collapsing by THP. + */ + pagevec_add(&pvec, page); + zone = page_zone(page); + zoneid = page_zone_id(page); - /* - * Try to fill the rest of pagevec using fast - * pte walk. This will also update start to - * the next page to process. Then munlock the - * pagevec. - */ - start = __munlock_pagevec_fill(&pvec, vma, - zoneid, start, end); - __munlock_pagevec(&pvec, zone); - goto next; - } + /* + * Try to fill the rest of pagevec using fast + * pte walk. This will also update start to + * the next page to process. Then munlock the + * pagevec. + */ + start = __munlock_pagevec_fill(&pvec, vma, + zoneid, start, end); + __munlock_pagevec(&pvec, zone); + goto next; } /* It's a bug to munlock in the middle of a THP page */ VM_BUG_ON((start >> PAGE_SHIFT) & page_mask); -- 2.1.4 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
next prev parent reply other threads:[~2015-06-03 17:07 UTC|newest] Thread overview: 114+ messages / expand[flat|nested] mbox.gz Atom feed top 2015-06-03 17:05 [PATCHv6 00/36] THP refcounting redesign Kirill A. Shutemov 2015-06-03 17:05 ` Kirill A. Shutemov 2015-06-03 17:05 ` [PATCHv6 01/36] mm, proc: adjust PSS calculation Kirill A. Shutemov 2015-06-03 17:05 ` Kirill A. Shutemov 2015-06-09 12:29 ` Vlastimil Babka 2015-06-09 12:29 ` Vlastimil Babka 2015-06-22 10:02 ` Kirill A. Shutemov 2015-06-22 10:02 ` Kirill A. Shutemov 2015-06-03 17:05 ` [PATCHv6 02/36] rmap: add argument to charge compound page Kirill A. Shutemov 2015-06-03 17:05 ` Kirill A. Shutemov 2015-06-03 17:05 ` [PATCHv6 03/36] memcg: adjust to support new THP refcounting Kirill A. Shutemov 2015-06-03 17:05 ` Kirill A. Shutemov 2015-06-03 17:05 ` [PATCHv6 04/36] mm, thp: adjust conditions when we can reuse the page on WP fault Kirill A. Shutemov 2015-06-03 17:05 ` Kirill A. Shutemov 2015-06-03 17:05 ` [PATCHv6 05/36] mm: adjust FOLL_SPLIT for new refcounting Kirill A. Shutemov 2015-06-03 17:05 ` Kirill A. Shutemov 2015-06-03 17:05 ` [PATCHv6 06/36] mm: handle PTE-mapped tail pages in gerneric fast gup implementaiton Kirill A. Shutemov 2015-06-03 17:05 ` Kirill A. Shutemov 2015-06-03 17:05 ` Kirill A. Shutemov [this message] 2015-06-03 17:05 ` [PATCHv6 07/36] thp, mlock: do not allow huge pages in mlocked area Kirill A. Shutemov 2015-06-03 17:05 ` [PATCHv6 08/36] khugepaged: ignore pmd tables with THP mapped with ptes Kirill A. Shutemov 2015-06-03 17:05 ` Kirill A. Shutemov 2015-06-03 17:05 ` [PATCHv6 09/36] thp: rename split_huge_page_pmd() to split_huge_pmd() Kirill A. Shutemov 2015-06-03 17:05 ` Kirill A. Shutemov 2015-06-03 17:05 ` [PATCHv6 10/36] mm, vmstats: new THP splitting event Kirill A. Shutemov 2015-06-03 17:05 ` Kirill A. Shutemov 2015-06-03 17:05 ` [PATCHv6 11/36] mm: temporally mark THP broken Kirill A. Shutemov 2015-06-03 17:05 ` Kirill A. Shutemov 2015-06-03 17:05 ` [PATCHv6 12/36] thp: drop all split_huge_page()-related code Kirill A. Shutemov 2015-06-03 17:05 ` Kirill A. Shutemov 2015-06-03 17:05 ` [PATCHv6 13/36] mm: drop tail page refcounting Kirill A. Shutemov 2015-06-03 17:05 ` Kirill A. Shutemov 2015-06-09 13:59 ` Vlastimil Babka 2015-06-09 13:59 ` Vlastimil Babka 2015-06-03 17:05 ` [PATCHv6 14/36] futex, thp: remove special case for THP in get_futex_key Kirill A. Shutemov 2015-06-03 17:05 ` Kirill A. Shutemov 2015-06-03 17:05 ` [PATCHv6 15/36] ksm: prepare to new THP semantics Kirill A. Shutemov 2015-06-03 17:05 ` Kirill A. Shutemov 2015-06-03 17:05 ` [PATCHv6 16/36] mm, thp: remove compound_lock Kirill A. Shutemov 2015-06-03 17:05 ` Kirill A. Shutemov 2015-06-03 17:05 ` [PATCHv6 17/36] arm64, thp: remove infrastructure for handling splitting PMDs Kirill A. Shutemov 2015-06-03 17:05 ` Kirill A. Shutemov 2015-06-03 17:05 ` [PATCHv6 18/36] arm, " Kirill A. Shutemov 2015-06-03 17:05 ` Kirill A. Shutemov 2015-06-03 17:05 ` [PATCHv6 19/36] mips, " Kirill A. Shutemov 2015-06-03 17:05 ` Kirill A. Shutemov 2015-06-03 17:05 ` [PATCHv6 20/36] powerpc, " Kirill A. Shutemov 2015-06-03 17:05 ` Kirill A. Shutemov 2015-06-03 17:05 ` [PATCHv6 21/36] s390, " Kirill A. Shutemov 2015-06-03 17:05 ` Kirill A. Shutemov 2015-06-03 17:05 ` [PATCHv6 22/36] sparc, " Kirill A. Shutemov 2015-06-03 17:05 ` Kirill A. Shutemov 2015-06-03 17:05 ` [PATCHv6 23/36] tile, " Kirill A. Shutemov 2015-06-03 17:05 ` Kirill A. Shutemov 2015-06-03 17:05 ` [PATCHv6 24/36] x86, " Kirill A. Shutemov 2015-06-03 17:05 ` Kirill A. Shutemov 2015-06-03 17:05 ` [PATCHv6 25/36] mm, " Kirill A. Shutemov 2015-06-03 17:05 ` Kirill A. Shutemov 2015-06-03 17:05 ` [PATCHv6 26/36] mm: rework mapcount accounting to enable 4k mapping of THPs Kirill A. Shutemov 2015-06-03 17:05 ` Kirill A. Shutemov 2015-06-10 13:47 ` Vlastimil Babka 2015-06-10 13:47 ` Vlastimil Babka 2015-06-22 10:22 ` Kirill A. Shutemov 2015-06-22 10:22 ` Kirill A. Shutemov 2015-06-03 17:05 ` [PATCHv6 27/36] mm: differentiate page_mapped() from page_mapcount() for compound pages Kirill A. Shutemov 2015-06-03 17:05 ` Kirill A. Shutemov 2015-06-09 10:58 ` Kirill A. Shutemov 2015-06-09 10:58 ` Kirill A. Shutemov 2015-06-10 14:34 ` Vlastimil Babka 2015-06-10 14:34 ` Vlastimil Babka 2015-06-03 17:05 ` [PATCHv6 28/36] mm, numa: skip PTE-mapped THP on numa fault Kirill A. Shutemov 2015-06-03 17:05 ` Kirill A. Shutemov 2015-06-03 17:06 ` [PATCHv6 29/36] thp: implement split_huge_pmd() Kirill A. Shutemov 2015-06-03 17:06 ` Kirill A. Shutemov 2015-06-11 9:49 ` Vlastimil Babka 2015-06-11 9:49 ` Vlastimil Babka 2015-06-22 11:14 ` Kirill A. Shutemov 2015-06-22 11:14 ` Kirill A. Shutemov 2015-06-22 16:01 ` Vlastimil Babka 2015-06-22 16:01 ` Vlastimil Babka 2015-06-03 17:06 ` [PATCHv6 30/36] thp: add option to setup migration entiries during PMD split Kirill A. Shutemov 2015-06-03 17:06 ` Kirill A. Shutemov 2015-06-03 17:06 ` [PATCHv6 31/36] thp, mm: split_huge_page(): caller need to lock page Kirill A. Shutemov 2015-06-03 17:06 ` Kirill A. Shutemov 2015-06-03 17:06 ` [PATCHv6 32/36] thp: reintroduce split_huge_page() Kirill A. Shutemov 2015-06-03 17:06 ` Kirill A. Shutemov 2015-06-10 15:44 ` Vlastimil Babka 2015-06-10 15:44 ` Vlastimil Babka 2015-06-22 11:28 ` Kirill A. Shutemov 2015-06-22 11:28 ` Kirill A. Shutemov 2015-06-03 17:06 ` [PATCHv6 33/36] migrate_pages: try to split pages on qeueuing Kirill A. Shutemov 2015-06-03 17:06 ` Kirill A. Shutemov 2015-06-11 9:27 ` Vlastimil Babka 2015-06-11 9:27 ` Vlastimil Babka 2015-06-22 11:35 ` Kirill A. Shutemov 2015-06-22 11:35 ` Kirill A. Shutemov 2015-06-03 17:06 ` [PATCHv6 34/36] thp: introduce deferred_split_huge_page() Kirill A. Shutemov 2015-06-03 17:06 ` Kirill A. Shutemov 2015-06-03 17:06 ` [PATCHv6 35/36] mm: re-enable THP Kirill A. Shutemov 2015-06-03 17:06 ` Kirill A. Shutemov 2015-06-03 17:06 ` [PATCHv6 36/36] thp: update documentation Kirill A. Shutemov 2015-06-03 17:06 ` Kirill A. Shutemov 2015-06-11 12:30 ` Vlastimil Babka 2015-06-11 12:30 ` Vlastimil Babka 2015-06-22 13:18 ` Kirill A. Shutemov 2015-06-22 13:18 ` Kirill A. Shutemov 2015-06-22 16:07 ` Vlastimil Babka 2015-06-22 16:07 ` Vlastimil Babka 2015-06-16 13:17 ` [PATCHv6 00/36] THP refcounting redesign Jerome Marchand 2015-06-22 13:21 ` Kirill A. Shutemov 2015-06-22 13:21 ` Kirill A. Shutemov 2015-06-22 13:32 ` Jerome Marchand 2015-06-22 13:39 ` Kirill A. Shutemov 2015-06-22 13:39 ` Kirill A. Shutemov
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