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* Merge branch 'drm-next' of git://people.freedesktop.org/~airlied/linuxLinus Torvalds2014-12-151-4/+5
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull drm updates from Dave Airlie: "Highlights: - AMD KFD driver merge This is the AMD HSA interface for exposing a lowlevel interface for GPGPU use. They have an open source userspace built on top of this interface, and the code looks as good as it was going to get out of tree. - Initial atomic modesetting work The need for an atomic modesetting interface to allow userspace to try and send a complete set of modesetting state to the driver has arisen, and been suffering from neglect this past year. No more, the start of the common code and changes for msm driver to use it are in this tree. Ongoing work to get the userspace ioctl finished and the code clean will probably wait until next kernel. - DisplayID 1.3 and tiled monitor exposed to userspace. Tiled monitor property is now exposed for userspace to make use of. - Rockchip drm driver merged. - imx gpu driver moved out of staging Other stuff: - core: panel - MIPI DSI + new panels. expose suggested x/y properties for virtual GPUs - i915: Initial Skylake (SKL) support gen3/4 reset work start of dri1/ums removal infoframe tracking fixes for lots of things. - nouveau: tegra k1 voltage support GM204 modesetting support GT21x memory reclocking work - radeon: CI dpm fixes GPUVM improvements Initial DPM fan control - rcar-du: HDMI support added removed some support for old boards slave encoder driver for Analog Devices adv7511 - exynos: Exynos4415 SoC support - msm: a4xx gpu support atomic helper conversion - tegra: iommu support universal plane support ganged-mode DSI support - sti: HDMI i2c improvements - vmwgfx: some late fixes. - qxl: use suggested x/y properties" * 'drm-next' of git://people.freedesktop.org/~airlied/linux: (969 commits) drm: sti: fix module compilation issue drm/i915: save/restore GMBUS freq across suspend/resume on gen4 drm: sti: correctly cleanup CRTC and planes drm: sti: add HQVDP plane drm: sti: add cursor plane drm: sti: enable auxiliary CRTC drm: sti: fix delay in VTG programming drm: sti: prepare sti_tvout to support auxiliary crtc drm: sti: use drm_crtc_vblank_{on/off} instead of drm_vblank_{on/off} drm: sti: fix hdmi avi infoframe drm: sti: remove event lock while disabling vblank drm: sti: simplify gdp code drm: sti: clear all mixer control drm: sti: remove gpio for HDMI hot plug detection drm: sti: allow to change hdmi ddc i2c adapter drm/doc: Document drm_add_modes_noedid() usage drm/i915: Remove '& 0xffff' from the mask given to WA_REG() drm/i915: Invert the mask and val arguments in wa_add() and WA_REG() drm: Zero out DRM object memory upon cleanup drm/i915/bdw: Fix the write setting up the WIZ hashing mode ...
| * mmu_notifier: call mmu_notifier_invalidate_range() from VMMJoerg Roedel2014-11-131-4/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add calls to the new mmu_notifier_invalidate_range() function to all places in the VMM that need it. Signed-off-by: Joerg Roedel <jroedel@suse.de> Reviewed-by: Andrea Arcangeli <aarcange@redhat.com> Reviewed-by: Jérôme Glisse <jglisse@redhat.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Rik van Riel <riel@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Johannes Weiner <jweiner@redhat.com> Cc: Jay Cornwall <Jay.Cornwall@amd.com> Cc: Oded Gabbay <Oded.Gabbay@amd.com> Cc: Suravee Suthikulpanit <Suravee.Suthikulpanit@amd.com> Cc: Jesse Barnes <jbarnes@virtuousgeek.org> Cc: David Woodhouse <dwmw2@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Oded Gabbay <oded.gabbay@amd.com>
* | Merge branch 'for-linus' of ↵Linus Torvalds2014-12-111-2/+3
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux Pull s390 updates from Martin Schwidefsky: "The most notable change for this pull request is the ftrace rework from Heiko. It brings a small performance improvement and the ground work to support a new gcc option to replace the mcount blocks with a single nop. Two new s390 specific system calls are added to emulate user space mmio for PCI, an artifact of the how PCI memory is accessed. Two patches for the memory management with changes to common code. For KVM mm_forbids_zeropage is added which disables the empty zero page for an mm that is used by a KVM process. And an optimization, pmdp_get_and_clear_full is added analog to ptep_get_and_clear_full. Some micro optimization for the cmpxchg and the spinlock code. And as usual bug fixes and cleanups" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (46 commits) s390/cputime: fix 31-bit compile s390/scm_block: make the number of reqs per HW req configurable s390/scm_block: handle multiple requests in one HW request s390/scm_block: allocate aidaw pages only when necessary s390/scm_block: use mempool to manage aidaw requests s390/eadm: change timeout value s390/mm: fix memory leak of ptlock in pmd_free_tlb s390: use local symbol names in entry[64].S s390/ptrace: always include vector registers in core files s390/simd: clear vector register pointer on fork/clone s390: translate cputime magic constants to macros s390/idle: convert open coded idle time seqcount s390/idle: add missing irq off lockdep annotation s390/debug: avoid function call for debug_sprintf_* s390/kprobes: fix instruction copy for out of line execution s390: remove diag 44 calls from cpu_relax() s390/dasd: retry partition detection s390/dasd: fix list corruption for sleep_on requests s390/dasd: fix infinite term I/O loop s390/dasd: remove unused code ...
| * | s390/mm: pmdp_get_and_clear_full optimizationMartin Schwidefsky2014-10-271-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | Analog to ptep_get_and_clear_full define a variant of the pmpd_get_and_clear primitive which gets the full hint from the mmu_gather struct. This allows s390 to avoid a costly instruction when destroying an address space. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
| * | mm: introduce mm_forbids_zeropage functionDominik Dingel2014-10-271-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add a new function stub to allow architectures to disable for an mm_structthe backing of non-present, anonymous pages with read-only empty zero pages. Signed-off-by: Dominik Dingel <dingel@linux.vnet.ibm.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* | | thp: do not mark zero-page pmd write-protected explicitlyKirill A. Shutemov2014-12-101-1/+0
| |/ |/| | | | | | | | | | | | | | | | | | | | | | | Zero pages can be used only in anonymous mappings, which never have writable vma->vm_page_prot: see protection_map in mm/mmap.c and __PX1X definitions. Let's drop redundant pmd_wrprotect() in set_huge_zero_page(). Signed-off-by: "Kirill A. Shutemov" <kirill@shutemov.name> Cc: Andrea Arcangeli <aarcange@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | mm, thp: fix collapsing of hugepages on madviseDavid Rientjes2014-10-291-5/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If an anonymous mapping is not allowed to fault thp memory and then madvise(MADV_HUGEPAGE) is used after fault, khugepaged will never collapse this memory into thp memory. This occurs because the madvise(2) handler for thp, hugepage_madvise(), clears VM_NOHUGEPAGE on the stack and it isn't stored in vma->vm_flags until the final action of madvise_behavior(). This causes the khugepaged_enter_vma_merge() to be a no-op in hugepage_madvise() when the vma had previously had VM_NOHUGEPAGE set. Fix this by passing the correct vma flags to the khugepaged mm slot handler. There's no chance khugepaged can run on this vma until after madvise_behavior() returns since we hold mm->mmap_sem. It would be possible to clear VM_NOHUGEPAGE directly from vma->vm_flags in hugepage_advise(), but I didn't want to introduce special case behavior into madvise_behavior(). I think it's best to just let it always set vma->vm_flags itself. Signed-off-by: David Rientjes <rientjes@google.com> Reported-by: Suleiman Souhlal <suleiman@google.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | mm: free compound page with correct orderYu Zhao2014-10-291-2/+2
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Compound page should be freed by put_page() or free_pages() with correct order. Not doing so will cause tail pages leaked. The compound order can be obtained by compound_order() or use HPAGE_PMD_ORDER in our case. Some people would argue the latter is faster but I prefer the former which is more general. This bug was observed not just on our servers (the worst case we saw is 11G leaked on a 48G machine) but also on our workstations running Ubuntu based distro. $ cat /proc/vmstat | grep thp_zero_page_alloc thp_zero_page_alloc 55 thp_zero_page_alloc_failed 0 This means there is (thp_zero_page_alloc - 1) * (2M - 4K) memory leaked. Fixes: 97ae17497e99 ("thp: implement refcounting for huge zero page") Signed-off-by: Yu Zhao <yuzhao@google.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Mel Gorman <mel@csn.ul.ie> Cc: David Rientjes <rientjes@google.com> Cc: Bob Liu <lliubbo@gmail.com> Cc: <stable@vger.kernel.org> [3.8+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: use VM_BUG_ON_MM where possibleSasha Levin2014-10-091-1/+1
| | | | | | | | Dump the contents of the relevant struct_mm when we hit the bug condition. Signed-off-by: Sasha Levin <sasha.levin@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: convert a few VM_BUG_ON callers to VM_BUG_ON_VMASasha Levin2014-10-091-3/+3
| | | | | | | | | | | | | | | | | | | | Trivially convert a few VM_BUG_ON calls to VM_BUG_ON_VMA to extract more information when they trigger. [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Sasha Levin <sasha.levin@oracle.com> Reviewed-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Konstantin Khlebnikov <khlebnikov@openvz.org> Cc: Rik van Riel <riel@redhat.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Michal Hocko <mhocko@suse.cz> Cc: Hugh Dickins <hughd@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Michel Lespinasse <walken@google.com> Cc: Minchan Kim <minchan@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm, THP: don't hold mmap_sem in khugepaged when allocating THPVlastimil Babka2014-10-091-13/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | When allocating huge page for collapsing, khugepaged currently holds mmap_sem for reading on the mm where collapsing occurs. Afterwards the read lock is dropped before write lock is taken on the same mmap_sem. Holding mmap_sem during whole huge page allocation is therefore useless, the vma needs to be rechecked after taking the write lock anyway. Furthemore, huge page allocation might involve a rather long sync compaction, and thus block any mmap_sem writers and i.e. affect workloads that perform frequent m(un)map or mprotect oterations. This patch simply releases the read lock before allocating a huge page. It also deletes an outdated comment that assumed vma must be stable, as it was using alloc_hugepage_vma(). This is no longer true since commit 9f1b868a13ac ("mm: thp: khugepaged: add policy for finding target node"). Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Cc: Minchan Kim <minchan@kernel.org> Acked-by: Mel Gorman <mgorman@suse.de> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Michal Nazarewicz <mina86@mina86.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Christoph Lameter <cl@linux.com> Cc: Rik van Riel <riel@redhat.com> Acked-by: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: numa: Do not mark PTEs pte_numa when splitting huge pagesMel Gorman2014-10-021-2/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch reverts 1ba6e0b50b ("mm: numa: split_huge_page: transfer the NUMA type from the pmd to the pte"). If a huge page is being split due a protection change and the tail will be in a PROT_NONE vma then NUMA hinting PTEs are temporarily created in the protected VMA. VM_RW|VM_PROTNONE |-----------------| ^ split here In the specific case above, it should get fixed up by change_pte_range() but there is a window of opportunity for weirdness to happen. Similarly, if a huge page is shrunk and split during a protection update but before pmd_numa is cleared then a pte_numa can be left behind. Instead of adding complexity trying to deal with the case, this patch will not mark PTEs NUMA when splitting a huge page. NUMA hinting faults will not be triggered which is marginal in comparison to the complexity in dealing with the corner cases during THP split. Cc: stable@vger.kernel.org Signed-off-by: Mel Gorman <mgorman@suse.de> Acked-by: Rik van Riel <riel@redhat.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: memcontrol: rewrite charge APIJohannes Weiner2014-08-081-20/+37
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | These patches rework memcg charge lifetime to integrate more naturally with the lifetime of user pages. This drastically simplifies the code and reduces charging and uncharging overhead. The most expensive part of charging and uncharging is the page_cgroup bit spinlock, which is removed entirely after this series. Here are the top-10 profile entries of a stress test that reads a 128G sparse file on a freshly booted box, without even a dedicated cgroup (i.e. executing in the root memcg). Before: 15.36% cat [kernel.kallsyms] [k] copy_user_generic_string 13.31% cat [kernel.kallsyms] [k] memset 11.48% cat [kernel.kallsyms] [k] do_mpage_readpage 4.23% cat [kernel.kallsyms] [k] get_page_from_freelist 2.38% cat [kernel.kallsyms] [k] put_page 2.32% cat [kernel.kallsyms] [k] __mem_cgroup_commit_charge 2.18% kswapd0 [kernel.kallsyms] [k] __mem_cgroup_uncharge_common 1.92% kswapd0 [kernel.kallsyms] [k] shrink_page_list 1.86% cat [kernel.kallsyms] [k] __radix_tree_lookup 1.62% cat [kernel.kallsyms] [k] __pagevec_lru_add_fn After: 15.67% cat [kernel.kallsyms] [k] copy_user_generic_string 13.48% cat [kernel.kallsyms] [k] memset 11.42% cat [kernel.kallsyms] [k] do_mpage_readpage 3.98% cat [kernel.kallsyms] [k] get_page_from_freelist 2.46% cat [kernel.kallsyms] [k] put_page 2.13% kswapd0 [kernel.kallsyms] [k] shrink_page_list 1.88% cat [kernel.kallsyms] [k] __radix_tree_lookup 1.67% cat [kernel.kallsyms] [k] __pagevec_lru_add_fn 1.39% kswapd0 [kernel.kallsyms] [k] free_pcppages_bulk 1.30% cat [kernel.kallsyms] [k] kfree As you can see, the memcg footprint has shrunk quite a bit. text data bss dec hex filename 37970 9892 400 48262 bc86 mm/memcontrol.o.old 35239 9892 400 45531 b1db mm/memcontrol.o This patch (of 4): The memcg charge API charges pages before they are rmapped - i.e. have an actual "type" - and so every callsite needs its own set of charge and uncharge functions to know what type is being operated on. Worse, uncharge has to happen from a context that is still type-specific, rather than at the end of the page's lifetime with exclusive access, and so requires a lot of synchronization. Rewrite the charge API to provide a generic set of try_charge(), commit_charge() and cancel_charge() transaction operations, much like what's currently done for swap-in: mem_cgroup_try_charge() attempts to reserve a charge, reclaiming pages from the memcg if necessary. mem_cgroup_commit_charge() commits the page to the charge once it has a valid page->mapping and PageAnon() reliably tells the type. mem_cgroup_cancel_charge() aborts the transaction. This reduces the charge API and enables subsequent patches to drastically simplify uncharging. As pages need to be committed after rmap is established but before they are added to the LRU, page_add_new_anon_rmap() must stop doing LRU additions again. Revive lru_cache_add_active_or_unevictable(). [hughd@google.com: fix shmem_unuse] [hughd@google.com: Add comments on the private use of -EAGAIN] Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Michal Hocko <mhocko@suse.cz> Cc: Tejun Heo <tj@kernel.org> Cc: Vladimir Davydov <vdavydov@parallels.com> Signed-off-by: Hugh Dickins <hughd@google.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm, thp: only collapse hugepages to nodes with affinity for zone_reclaim_modeDavid Rientjes2014-08-061-0/+26
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 9f1b868a13ac ("mm: thp: khugepaged: add policy for finding target node") improved the previous khugepaged logic which allocated a transparent hugepages from the node of the first page being collapsed. However, it is still possible to collapse pages to remote memory which may suffer from additional access latency. With the current policy, it is possible that 255 pages (with PAGE_SHIFT == 12) will be collapsed remotely if the majority are allocated from that node. When zone_reclaim_mode is enabled, it means the VM should make every attempt to allocate locally to prevent NUMA performance degradation. In this case, we do not want to collapse hugepages to remote nodes that would suffer from increased access latency. Thus, when zone_reclaim_mode is enabled, only allow collapsing to nodes with RECLAIM_DISTANCE or less. There is no functional change for systems that disable zone_reclaim_mode. Signed-off-by: David Rientjes <rientjes@google.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Mel Gorman <mgorman@suse.de> Cc: Rik van Riel <riel@redhat.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Bob Liu <bob.liu@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: huge_memory: use GFP_TRANSHUGE when charging huge pagesJohannes Weiner2014-08-061-3/+3
| | | | | | | | | | | | | | | | | | | | | Transparent huge page charges prefer falling back to regular pages rather than spending a lot of time in direct reclaim. Desired reclaim behavior is usually declared in the gfp mask, but THP charges use GFP_KERNEL and then rely on the fact that OOM is disabled for THP charges, and that OOM-disabled charges don't retry reclaim. Needless to say, this is anything but obvious and quite error prone. Convert THP charges to use GFP_TRANSHUGE instead, which implies __GFP_NORETRY, to indicate the low-latency requirement. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Michal Hocko <mhocko@suse.cz> Cc: Hugh Dickins <hughd@google.com> Cc: Tejun Heo <tj@kernel.org> Cc: Vladimir Davydov <vdavydov@parallels.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm, thp: replace smp_mb after atomic_add by smp_mb__after_atomicWaiman Long2014-08-061-1/+1
| | | | | | | | | | | | | | | | | | | | | | In some architectures like x86, atomic_add() is a full memory barrier. In that case, an additional smp_mb() is just a waste of time. This patch replaces that smp_mb() by smp_mb__after_atomic() which will avoid the redundant memory barrier in some architectures. With a 3.16-rc1 based kernel, this patch reduced the execution time of breaking 1000 transparent huge pages from 38,245us to 30,964us. A reduction of 19% which is quite sizeable. It also reduces the %cpu time of the __split_huge_page_refcount function in the perf profile from 2.18% to 1.15%. Signed-off-by: Waiman Long <Waiman.Long@hp.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Rik van Riel <riel@redhat.com> Cc: Scott J Norton <scott.norton@hp.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm, thp: move invariant bug check out of loop in __split_huge_page_mapWaiman Long2014-08-061-2/+2
| | | | | | | | | | | | | | | | | | | | | | In __split_huge_page_map(), the check for page_mapcount(page) is invariant within the for loop. Because of the fact that the macro is implemented using atomic_read(), the redundant check cannot be optimized away by the compiler leading to unnecessary read to the page structure. This patch moves the invariant bug check out of the loop so that it will be done only once. On a 3.16-rc1 based kernel, the execution time of a microbenchmark that broke up 1000 transparent huge pages using munmap() had an execution time of 38,245us and 38,548us with and without the patch respectively. The performance gain is about 1%. Signed-off-by: Waiman Long <Waiman.Long@hp.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Rik van Riel <riel@redhat.com> Cc: Scott J Norton <scott.norton@hp.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: let mm_find_pmd fix buggy race with THP faultHugh Dickins2014-06-231-6/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Trinity has reported: BUG: unable to handle kernel NULL pointer dereference at 0000000000000018 IP: __lock_acquire (kernel/locking/lockdep.c:3070 (discriminator 1)) CPU: 6 PID: 16173 Comm: trinity-c364 Tainted: G W 3.15.0-rc1-next-20140415-sasha-00020-gaa90d09 #398 lock_acquire (arch/x86/include/asm/current.h:14 kernel/locking/lockdep.c:3602) _raw_spin_lock (include/linux/spinlock_api_smp.h:143 kernel/locking/spinlock.c:151) remove_migration_pte (mm/migrate.c:137) rmap_walk (mm/rmap.c:1628 mm/rmap.c:1699) remove_migration_ptes (mm/migrate.c:224) migrate_pages (mm/migrate.c:922 mm/migrate.c:960 mm/migrate.c:1126) migrate_misplaced_page (mm/migrate.c:1733) __handle_mm_fault (mm/memory.c:3762 mm/memory.c:3812 mm/memory.c:3925) handle_mm_fault (mm/memory.c:3948) __get_user_pages (mm/memory.c:1851) __mlock_vma_pages_range (mm/mlock.c:255) __mm_populate (mm/mlock.c:711) SyS_mlockall (include/linux/mm.h:1799 mm/mlock.c:817 mm/mlock.c:791) I believe this comes about because, whereas collapsing and splitting THP functions take anon_vma lock in write mode (which excludes concurrent rmap walks), faulting THP functions (write protection and misplaced NUMA) do not - and mostly they do not need to. But they do use a pmdp_clear_flush(), set_pmd_at() sequence which, for an instant (indeed, for a long instant, given the inter-CPU TLB flush in there), leaves *pmd neither present not trans_huge. Which can confuse a concurrent rmap walk, as when removing migration ptes, seen in the dumped trace. Although that rmap walk has a 4k page to insert, anon_vmas containing THPs are in no way segregated from 4k-page anon_vmas, so the 4k-intent mm_find_pmd() does need to cope with that instant when a trans_huge pmd is temporarily absent. I don't think we need strengthen the locking at the THP end: it's easily handled with an ACCESS_ONCE() before testing both conditions. And since mm_find_pmd() had only one caller who wanted a THP rather than a pmd, let's slightly repurpose it to fail when it hits a THP or non-present pmd, and open code split_huge_page_address() again. Signed-off-by: Hugh Dickins <hughd@google.com> Reported-by: Sasha Levin <sasha.levin@oracle.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Konstantin Khlebnikov <koct9i@gmail.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Bob Liu <bob.liu@oracle.com> Cc: Christoph Lameter <cl@gentwo.org> Cc: Dave Jones <davej@redhat.com> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: thp: fix DEBUG_PAGEALLOC oops in copy_page_rep()Hugh Dickins2014-06-231-4/+35
| | | | | | | | | | | | | | | | | | | | | | | | | | | Trinity has for over a year been reporting a CONFIG_DEBUG_PAGEALLOC oops in copy_page_rep() called from copy_user_huge_page() called from do_huge_pmd_wp_page(). I believe this is a DEBUG_PAGEALLOC false positive, due to the source page being split, and a tail page freed, while copy is in progress; and not a problem without DEBUG_PAGEALLOC, since the pmd_same() check will prevent a miscopy from being made visible. Fix by adding get_user_huge_page() and put_user_huge_page(): reducing to the usual get_page() and put_page() on head page in the usual config; but get and put references to all of the tail pages when DEBUG_PAGEALLOC. [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Hugh Dickins <hughd@google.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Reported-by: Sasha Levin <sasha.levin@oracle.com> Tested-by: Sasha Levin <sasha.levin@oracle.com> Cc: Dave Jones <davej@redhat.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm/huge_memory.c: complete conversion to pr_foo()Andrew Morton2014-06-041-11/+11
| | | | | | | | | | It was using a mix of pr_foo() and printk(KERN_ERR ...). Cc: Rik van Riel <riel@redhat.com> Cc: Mel Gorman <mgorman@suse.de> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* thp: consolidate assert checks in __split_huge_page()Kirill A. Shutemov2014-06-041-4/+6
| | | | | | | | | | | | It doesn't make sense to have two assert checks for each invariant: one for printing and one for BUG(). Let's trigger BUG() if we print error message. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge branch 'sched/urgent' into sched/core, to avoid conflictsIngo Molnar2014-05-071-88/+25
|\ | | | | | | Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * thp: close race between split and zap huge pagesKirill A. Shutemov2014-04-181-3/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Sasha Levin has reported two THP BUGs[1][2]. I believe both of them have the same root cause. Let's look to them one by one. The first bug[1] is "kernel BUG at mm/huge_memory.c:1829!". It's BUG_ON(mapcount != page_mapcount(page)) in __split_huge_page(). From my testing I see that page_mapcount() is higher than mapcount here. I think it happens due to race between zap_huge_pmd() and page_check_address_pmd(). page_check_address_pmd() misses PMD which is under zap: CPU0 CPU1 zap_huge_pmd() pmdp_get_and_clear() __split_huge_page() anon_vma_interval_tree_foreach() __split_huge_page_splitting() page_check_address_pmd() mm_find_pmd() /* * We check if PMD present without taking ptl: no * serialization against zap_huge_pmd(). We miss this PMD, * it's not accounted to 'mapcount' in __split_huge_page(). */ pmd_present(pmd) == 0 BUG_ON(mapcount != page_mapcount(page)) // CRASH!!! page_remove_rmap(page) atomic_add_negative(-1, &page->_mapcount) The second bug[2] is "kernel BUG at mm/huge_memory.c:1371!". It's VM_BUG_ON_PAGE(!PageHead(page), page) in zap_huge_pmd(). This happens in similar way: CPU0 CPU1 zap_huge_pmd() pmdp_get_and_clear() page_remove_rmap(page) atomic_add_negative(-1, &page->_mapcount) __split_huge_page() anon_vma_interval_tree_foreach() __split_huge_page_splitting() page_check_address_pmd() mm_find_pmd() pmd_present(pmd) == 0 /* The same comment as above */ /* * No crash this time since we already decremented page->_mapcount in * zap_huge_pmd(). */ BUG_ON(mapcount != page_mapcount(page)) /* * We split the compound page here into small pages without * serialization against zap_huge_pmd() */ __split_huge_page_refcount() VM_BUG_ON_PAGE(!PageHead(page), page); // CRASH!!! So my understanding the problem is pmd_present() check in mm_find_pmd() without taking page table lock. The bug was introduced by me commit with commit 117b0791ac42. Sorry for that. :( Let's open code mm_find_pmd() in page_check_address_pmd() and do the check under page table lock. Note that __page_check_address() does the same for PTE entires if sync != 0. I've stress tested split and zap code paths for 36+ hours by now and don't see crashes with the patch applied. Before it took <20 min to trigger the first bug and few hours for second one (if we ignore first). [1] https://lkml.kernel.org/g/<53440991.9090001@oracle.com> [2] https://lkml.kernel.org/g/<5310C56C.60709@oracle.com> Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Reported-by: Sasha Levin <sasha.levin@oracle.com> Tested-by: Sasha Levin <sasha.levin@oracle.com> Cc: Bob Liu <lliubbo@gmail.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Rik van Riel <riel@redhat.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Michel Lespinasse <walken@google.com> Cc: Dave Jones <davej@redhat.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: <stable@vger.kernel.org> [3.13+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * memcg: rename high level charging functionsMichal Hocko2014-04-071-4/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | mem_cgroup_newpage_charge is used only for charging anonymous memory so it is better to rename it to mem_cgroup_charge_anon. mem_cgroup_cache_charge is used for file backed memory so rename it to mem_cgroup_charge_file. Signed-off-by: Michal Hocko <mhocko@suse.cz> Cc: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * mm: revert "thp: make MADV_HUGEPAGE check for mm->def_flags"Alex Thorlton2014-04-071-4/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The main motivation behind this patch is to provide a way to disable THP for jobs where the code cannot be modified, and using a malloc hook with madvise is not an option (i.e. statically allocated data). This patch allows us to do just that, without affecting other jobs running on the system. We need to do this sort of thing for jobs where THP hurts performance, due to the possibility of increased remote memory accesses that can be created by situations such as the following: When you touch 1 byte of an untouched, contiguous 2MB chunk, a THP will be handed out, and the THP will be stuck on whatever node the chunk was originally referenced from. If many remote nodes need to do work on that same chunk, they'll be making remote accesses. With THP disabled, 4K pages can be handed out to separate nodes as they're needed, greatly reducing the amount of remote accesses to memory. This patch is based on some of my work combined with some suggestions/patches given by Oleg Nesterov. The main goal here is to add a prctl switch to allow us to disable to THP on a per mm_struct basis. Here's a bit of test data with the new patch in place... First with the flag unset: # perf stat -a ./prctl_wrapper_mmv3 0 ./thp_pthread -C 0 -m 0 -c 512 -b 256g Setting thp_disabled for this task... thp_disable: 0 Set thp_disabled state to 0 Process pid = 18027 PF/ MAX MIN TOTCPU/ TOT_PF/ TOT_PF/ WSEC/ TYPE: CPUS WALL WALL SYS USER TOTCPU CPU WALL_SEC SYS_SEC CPU NODES 512 1.120 0.060 0.000 0.110 0.110 0.000 28571428864 -9223372036854775808 55803572 23 Performance counter stats for './prctl_wrapper_mmv3_hack 0 ./thp_pthread -C 0 -m 0 -c 512 -b 256g': 273719072.841402 task-clock # 641.026 CPUs utilized [100.00%] 1,008,986 context-switches # 0.000 M/sec [100.00%] 7,717 CPU-migrations # 0.000 M/sec [100.00%] 1,698,932 page-faults # 0.000 M/sec 355,222,544,890,379 cycles # 1.298 GHz [100.00%] 536,445,412,234,588 stalled-cycles-frontend # 151.02% frontend cycles idle [100.00%] 409,110,531,310,223 stalled-cycles-backend # 115.17% backend cycles idle [100.00%] 148,286,797,266,411 instructions # 0.42 insns per cycle # 3.62 stalled cycles per insn [100.00%] 27,061,793,159,503 branches # 98.867 M/sec [100.00%] 1,188,655,196 branch-misses # 0.00% of all branches 427.001706337 seconds time elapsed Now with the flag set: # perf stat -a ./prctl_wrapper_mmv3 1 ./thp_pthread -C 0 -m 0 -c 512 -b 256g Setting thp_disabled for this task... thp_disable: 1 Set thp_disabled state to 1 Process pid = 144957 PF/ MAX MIN TOTCPU/ TOT_PF/ TOT_PF/ WSEC/ TYPE: CPUS WALL WALL SYS USER TOTCPU CPU WALL_SEC SYS_SEC CPU NODES 512 0.620 0.260 0.250 0.320 0.570 0.001 51612901376 128000000000 100806448 23 Performance counter stats for './prctl_wrapper_mmv3_hack 1 ./thp_pthread -C 0 -m 0 -c 512 -b 256g': 138789390.540183 task-clock # 641.959 CPUs utilized [100.00%] 534,205 context-switches # 0.000 M/sec [100.00%] 4,595 CPU-migrations # 0.000 M/sec [100.00%] 63,133,119 page-faults # 0.000 M/sec 147,977,747,269,768 cycles # 1.066 GHz [100.00%] 200,524,196,493,108 stalled-cycles-frontend # 135.51% frontend cycles idle [100.00%] 105,175,163,716,388 stalled-cycles-backend # 71.07% backend cycles idle [100.00%] 180,916,213,503,160 instructions # 1.22 insns per cycle # 1.11 stalled cycles per insn [100.00%] 26,999,511,005,868 branches # 194.536 M/sec [100.00%] 714,066,351 branch-misses # 0.00% of all branches 216.196778807 seconds time elapsed As with previous versions of the patch, We're getting about a 2x performance increase here. Here's a link to the test case I used, along with the little wrapper to activate the flag: http://oss.sgi.com/projects/memtests/thp_pthread_mmprctlv3.tar.gz This patch (of 3): Revert commit 8e72033f2a48 and add in code to fix up any issues caused by the revert. The revert is necessary because hugepage_madvise would return -EINVAL when VM_NOHUGEPAGE is set, which will break subsequent chunks of this patch set. Here's a snip of an e-mail from Gerald detailing the original purpose of this code, and providing justification for the revert: "The intent of commit 8e72033f2a48 was to guard against any future programming errors that may result in an madvice(MADV_HUGEPAGE) on guest mappings, which would crash the kernel. Martin suggested adding the bit to arch/s390/mm/pgtable.c, if 8e72033f2a48 was to be reverted, because that check will also prevent a kernel crash in the case described above, it will now send a SIGSEGV instead. This would now also allow to do the madvise on other parts, if needed, so it is a more flexible approach. One could also say that it would have been better to do it this way right from the beginning..." Signed-off-by: Alex Thorlton <athorlton@sgi.com> Suggested-by: Oleg Nesterov <oleg@redhat.com> Tested-by: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Gerald Schaefer <gerald.schaefer@de.ibm.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Rik van Riel <riel@redhat.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * mm, thp: drop do_huge_pmd_wp_zero_page_fallback()Kirill A. Shutemov2014-04-031-77/+2
| | | | | | | | | | | | | | | | | | | | | | | | I've realized that there's no need for do_huge_pmd_wp_zero_page_fallback(). We can just split zero page with split_huge_page_pmd() and return VM_FAULT_FALLBACK. handle_pte_fault() will handle write-protection fault for us. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | sched, treewide: Replace hardcoded nice values with MIN_NICE/MAX_NICEDongsheng Yang2014-04-181-1/+1
|/ | | | | | | | | | | | | | | | | | | | | | | | Replace various -20/+19 hardcoded nice values with MIN_NICE/MAX_NICE. Signed-off-by: Dongsheng Yang <yangds.fnst@cn.fujitsu.com> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/ff13819fd09b7a5dba5ab5ae797f2e7019bdfa17.1394532288.git.yangds.fnst@cn.fujitsu.com Cc: devel@driverdev.osuosl.org Cc: devicetree@vger.kernel.org Cc: fcoe-devel@open-fcoe.org Cc: linux390@de.ibm.com Cc: linux-kernel@vger.kernel.org Cc: linux-mm@kvack.org Cc: linux-s390@vger.kernel.org Cc: linux-scsi@vger.kernel.org Cc: nbd-general@lists.sourceforge.net Cc: ocfs2-devel@oss.oracle.com Cc: openipmi-developer@lists.sourceforge.net Cc: qla2xxx-upstream@qlogic.com Cc: linux-arch@vger.kernel.org [ Consolidated the patches, twiddled the changelog. ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
* mm: include VM_MIXEDMAP flag in the VM_SPECIAL list to avoid m(un)lockingVlastimil Babka2014-03-041-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Daniel Borkmann reported a VM_BUG_ON assertion failing: ------------[ cut here ]------------ kernel BUG at mm/mlock.c:528! invalid opcode: 0000 [#1] SMP Modules linked in: ccm arc4 iwldvm [...] video CPU: 3 PID: 2266 Comm: netsniff-ng Not tainted 3.14.0-rc2+ #8 Hardware name: LENOVO 2429BP3/2429BP3, BIOS G4ET37WW (1.12 ) 05/29/2012 task: ffff8801f87f9820 ti: ffff88002cb44000 task.ti: ffff88002cb44000 RIP: 0010:[<ffffffff81171ad0>] [<ffffffff81171ad0>] munlock_vma_pages_range+0x2e0/0x2f0 Call Trace: do_munmap+0x18f/0x3b0 vm_munmap+0x41/0x60 SyS_munmap+0x22/0x30 system_call_fastpath+0x1a/0x1f RIP munlock_vma_pages_range+0x2e0/0x2f0 ---[ end trace a0088dcf07ae10f2 ]--- because munlock_vma_pages_range() thinks it's unexpectedly in the middle of a THP page. This can be reproduced with default config since 3.11 kernels. A reproducer can be found in the kernel's selftest directory for networking by running ./psock_tpacket. The problem is that an order=2 compound page (allocated by alloc_one_pg_vec_page() is part of the munlocked VM_MIXEDMAP vma (mapped by packet_mmap()) and mistaken for a THP page and assumed to be order=9. The checks for THP in munlock came with commit ff6a6da60b89 ("mm: accelerate munlock() treatment of THP pages"), i.e. since 3.9, but did not trigger a bug. It just makes munlock_vma_pages_range() skip such compound pages until the next 512-pages-aligned page, when it encounters a head page. This is however not a problem for vma's where mlocking has no effect anyway, but it can distort the accounting. Since commit 7225522bb429 ("mm: munlock: batch non-THP page isolation and munlock+putback using pagevec") this can trigger a VM_BUG_ON in PageTransHuge() check. This patch fixes the issue by adding VM_MIXEDMAP flag to VM_SPECIAL, a list of flags that make vma's non-mlockable and non-mergeable. The reasoning is that VM_MIXEDMAP vma's are similar to VM_PFNMAP, which is already on the VM_SPECIAL list, and both are intended for non-LRU pages where mlocking makes no sense anyway. Related Lkml discussion can be found in [2]. [1] tools/testing/selftests/net/psock_tpacket [2] https://lkml.org/lkml/2014/1/10/427 Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Daniel Borkmann <dborkman@redhat.com> Reported-by: Daniel Borkmann <dborkman@redhat.com> Tested-by: Daniel Borkmann <dborkman@redhat.com> Cc: Thomas Hellstrom <thellstrom@vmware.com> Cc: John David Anglin <dave.anglin@bell.net> Cc: HATAYAMA Daisuke <d.hatayama@jp.fujitsu.com> Cc: Konstantin Khlebnikov <khlebnikov@openvz.org> Cc: Carsten Otte <cotte@de.ibm.com> Cc: Jared Hulbert <jaredeh@gmail.com> Tested-by: Hannes Frederic Sowa <hannes@stressinduktion.org> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by: Rik van Riel <riel@redhat.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: <stable@vger.kernel.org> [3.11.x+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm, thp: fix infinite loop on memcg OOMKirill A. Shutemov2014-02-251-3/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Masayoshi Mizuma reported a bug with the hang of an application under the memcg limit. It happens on write-protection fault to huge zero page If we successfully allocate a huge page to replace zero page but hit the memcg limit we need to split the zero page with split_huge_page_pmd() and fallback to small pages. The other part of the problem is that VM_FAULT_OOM has special meaning in do_huge_pmd_wp_page() context. __handle_mm_fault() expects the page to be split if it sees VM_FAULT_OOM and it will will retry page fault handling. This causes an infinite loop if the page was not split. do_huge_pmd_wp_zero_page_fallback() can return VM_FAULT_OOM if it failed to allocate one small page, so fallback to small pages will not help. The solution for this part is to replace VM_FAULT_OOM with VM_FAULT_FALLBACK is fallback required. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Reported-by: Masayoshi Mizuma <m.mizuma@jp.fujitsu.com> Reviewed-by: Michal Hocko <mhocko@suse.cz> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: David Rientjes <rientjes@google.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: Use ptep/pmdp_set_numa() for updating _PAGE_NUMA bitAneesh Kumar K.V2014-02-171-7/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Archs like ppc64 doesn't do tlb flush in set_pte/pmd functions when using a hash table MMU for various reasons (the flush is handled as part of the PTE modification when necessary). ppc64 thus doesn't implement flush_tlb_range for hash based MMUs. Additionally ppc64 require the tlb flushing to be batched within ptl locks. The reason to do that is to ensure that the hash page table is in sync with linux page table. We track the hpte index in linux pte and if we clear them without flushing hash and drop the ptl lock, we can have another cpu update the pte and can end up with duplicate entry in the hash table, which is fatal. We also want to keep set_pte_at simpler by not requiring them to do hash flush for performance reason. We do that by assuming that set_pte_at() is never *ever* called on a PTE that is already valid. This was the case until the NUMA code went in which broke that assumption. Fix that by introducing a new pair of helpers to set _PAGE_NUMA in a way similar to ptep/pmdp_set_wrprotect(), with a generic implementation using set_pte_at() and a powerpc specific one using the appropriate mechanism needed to keep the hash table in sync. Acked-by: Mel Gorman <mgorman@suse.de> Reviewed-by: Rik van Riel <riel@redhat.com> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* Merge branch 'merge' of ↵Linus Torvalds2014-01-271-9/+5
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc Pull powerpc mremap fix from Ben Herrenschmidt: "This is the patch that I had sent after -rc8 and which we decided to wait before merging. It's based on a different tree than my -next branch (it needs some pre-reqs that were in -rc4 or so while my -next is based on -rc1) so I left it as a separate branch for your to pull. It's identical to the request I did 2 or 3 weeks back. This fixes crashes in mremap with THP on powerpc. The fix however requires a small change in the generic code. It moves a condition into a helper we can override from the arch which is harmless, but it *also* slightly changes the order of the set_pmd and the withdraw & deposit, which should be fine according to Kirill (who wrote that code) but I agree -rc8 is a bit late... It was acked by Kirill and Andrew told me to just merge it via powerpc" * 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc: powerpc/thp: Fix crash on mremap
| * powerpc/thp: Fix crash on mremapAneesh Kumar K.V2014-01-151-9/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch fix the below crash NIP [c00000000004cee4] .__hash_page_thp+0x2a4/0x440 LR [c0000000000439ac] .hash_page+0x18c/0x5e0 ... Call Trace: [c000000736103c40] [00001ffffb000000] 0x1ffffb000000(unreliable) [437908.479693] [c000000736103d50] [c0000000000439ac] .hash_page+0x18c/0x5e0 [437908.479699] [c000000736103e30] [c00000000000924c] .do_hash_page+0x4c/0x58 On ppc64 we use the pgtable for storing the hpte slot information and store address to the pgtable at a constant offset (PTRS_PER_PMD) from pmd. On mremap, when we switch the pmd, we need to withdraw and deposit the pgtable again, so that we find the pgtable at PTRS_PER_PMD offset from new pmd. We also want to move the withdraw and deposit before the set_pmd so that, when page fault find the pmd as trans huge we can be sure that pgtable can be located at the offset. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* | mm: audit/fix non-modular users of module_init in core codePaul Gortmaker2014-01-231-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Code that is obj-y (always built-in) or dependent on a bool Kconfig (built-in or absent) can never be modular. So using module_init as an alias for __initcall can be somewhat misleading. Fix these up now, so that we can relocate module_init from init.h into module.h in the future. If we don't do this, we'd have to add module.h to obviously non-modular code, and that would be a worse thing. The audit targets the following module_init users for change: mm/ksm.c bool KSM mm/mmap.c bool MMU mm/huge_memory.c bool TRANSPARENT_HUGEPAGE mm/mmu_notifier.c bool MMU_NOTIFIER Note that direct use of __initcall is discouraged, vs. one of the priority categorized subgroups. As __initcall gets mapped onto device_initcall, our use of subsys_initcall (which makes sense for these files) will thus change this registration from level 6-device to level 4-subsys (i.e. slightly earlier). However no observable impact of that difference has been observed during testing. One might think that core_initcall (l2) or postcore_initcall (l3) would be more appropriate for anything in mm/ but if we look at some actual init functions themselves, we see things like: mm/huge_memory.c --> hugepage_init --> hugepage_init_sysfs mm/mmap.c --> init_user_reserve --> sysctl_user_reserve_kbytes mm/ksm.c --> ksm_init --> sysfs_create_group and hence the choice of subsys_initcall (l4) seems reasonable, and at the same time minimizes the risk of changing the priority too drastically all at once. We can adjust further in the future. Also, several instances of missing ";" at EOL are fixed. Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | mm: show message when updating min_free_kbytes in thpHan Pingtian2014-01-231-1/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | min_free_kbytes may be raised during THP's initialization. Sometimes, this will change the value which was set by the user. Showing this message will clarify this confusion. Only show this message when changing a value which was set by the user according to Michal Hocko's suggestion. Show the old value of min_free_kbytes according to Dave Hansen's suggestion. This will give user the chance to restore old value of min_free_kbytes. Signed-off-by: Han Pingtian <hanpt@linux.vnet.ibm.com> Reviewed-by: Michal Hocko <mhocko@suse.cz> Cc: David Rientjes <rientjes@google.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Dave Hansen <dave.hansen@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | mm: dump page when hitting a VM_BUG_ON using VM_BUG_ON_PAGESasha Levin2014-01-231-18/+18
|/ | | | | | | | | | | | | | | | | | | | Most of the VM_BUG_ON assertions are performed on a page. Usually, when one of these assertions fails we'll get a BUG_ON with a call stack and the registers. I've recently noticed based on the requests to add a small piece of code that dumps the page to various VM_BUG_ON sites that the page dump is quite useful to people debugging issues in mm. This patch adds a VM_BUG_ON_PAGE(cond, page) which beyond doing what VM_BUG_ON() does, also dumps the page before executing the actual BUG_ON. [akpm@linux-foundation.org: fix up includes] Signed-off-by: Sasha Levin <sasha.levin@oracle.com> Cc: "Kirill A. Shutemov" <kirill@shutemov.name> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* thp: fix copy_page_rep GPF by testing is_huge_zero_pmd once onlyHugh Dickins2014-01-121-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We see General Protection Fault on RSI in copy_page_rep: that RSI is what you get from a NULL struct page pointer. RIP: 0010:[<ffffffff81154955>] [<ffffffff81154955>] copy_page_rep+0x5/0x10 RSP: 0000:ffff880136e15c00 EFLAGS: 00010286 RAX: ffff880000000000 RBX: ffff880136e14000 RCX: 0000000000000200 RDX: 6db6db6db6db6db7 RSI: db73880000000000 RDI: ffff880dd0c00000 RBP: ffff880136e15c18 R08: 0000000000000200 R09: 000000000005987c R10: 000000000005987c R11: 0000000000000200 R12: 0000000000000001 R13: ffffea00305aa000 R14: 0000000000000000 R15: 0000000000000000 FS: 00007f195752f700(0000) GS:ffff880c7fc20000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000093010000 CR3: 00000001458e1000 CR4: 00000000000027e0 Call Trace: copy_user_huge_page+0x93/0xab do_huge_pmd_wp_page+0x710/0x815 handle_mm_fault+0x15d8/0x1d70 __do_page_fault+0x14d/0x840 do_page_fault+0x2f/0x90 page_fault+0x22/0x30 do_huge_pmd_wp_page() tests is_huge_zero_pmd(orig_pmd) four times: but since shrink_huge_zero_page() can free the huge_zero_page, and we have no hold of our own on it here (except where the fourth test holds page_table_lock and has checked pmd_same), it's possible for it to answer yes the first time, but no to the second or third test. Change all those last three to tests for NULL page. (Note: this is not the same issue as trinity's DEBUG_PAGEALLOC BUG in copy_page_rep with RSI: ffff88009c422000, reported by Sasha Levin in https://lkml.org/lkml/2013/3/29/103. I believe that one is due to the source page being split, and a tail page freed, while copy is in progress; and not a problem without DEBUG_PAGEALLOC, since the pmd_same check will prevent a miscopy from being made visible.) Fixes: 97ae17497e99 ("thp: implement refcounting for huge zero page") Signed-off-by: Hugh Dickins <hughd@google.com> Cc: stable@vger.kernel.org # v3.10 v3.11 v3.12 Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: remove bogus warning in copy_huge_pmd()Mel Gorman2014-01-021-3/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Sasha Levin reported the following warning being triggered WARNING: CPU: 28 PID: 35287 at mm/huge_memory.c:887 copy_huge_pmd+0x145/ 0x3a0() Call Trace: copy_huge_pmd+0x145/0x3a0 copy_page_range+0x3f2/0x560 dup_mmap+0x2c9/0x3d0 dup_mm+0xad/0x150 copy_process+0xa68/0x12e0 do_fork+0x96/0x270 SyS_clone+0x16/0x20 stub_clone+0x69/0x90 This warning was introduced by "mm: numa: Avoid unnecessary disruption of NUMA hinting during migration" for paranoia reasons but the warning is bogus. I was thinking of parallel races between NUMA hinting faults and forks but this warning would also be triggered by a parallel reclaim splitting a THP during a fork. Remote the bogus warning. Signed-off-by: Mel Gorman <mgorman@suse.de> Reported-by: Sasha Levin <sasha.levin@oracle.com> Cc: Alex Thorlton <athorlton@sgi.com> Cc: Rik van Riel <riel@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: numa: defer TLB flush for THP migration as long as possibleMel Gorman2013-12-181-7/+0
| | | | | | | | | | | | THP migration can fail for a variety of reasons. Avoid flushing the TLB to deal with THP migration races until the copy is ready to start. Signed-off-by: Mel Gorman <mgorman@suse.de> Reviewed-by: Rik van Riel <riel@redhat.com> Cc: Alex Thorlton <athorlton@sgi.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: fix TLB flush race between migration, and change_protection_rangeRik van Riel2013-12-181-0/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There are a few subtle races, between change_protection_range (used by mprotect and change_prot_numa) on one side, and NUMA page migration and compaction on the other side. The basic race is that there is a time window between when the PTE gets made non-present (PROT_NONE or NUMA), and the TLB is flushed. During that time, a CPU may continue writing to the page. This is fine most of the time, however compaction or the NUMA migration code may come in, and migrate the page away. When that happens, the CPU may continue writing, through the cached translation, to what is no longer the current memory location of the process. This only affects x86, which has a somewhat optimistic pte_accessible. All other architectures appear to be safe, and will either always flush, or flush whenever there is a valid mapping, even with no permissions (SPARC). The basic race looks like this: CPU A CPU B CPU C load TLB entry make entry PTE/PMD_NUMA fault on entry read/write old page start migrating page change PTE/PMD to new page read/write old page [*] flush TLB reload TLB from new entry read/write new page lose data [*] the old page may belong to a new user at this point! The obvious fix is to flush remote TLB entries, by making sure that pte_accessible aware of the fact that PROT_NONE and PROT_NUMA memory may still be accessible if there is a TLB flush pending for the mm. This should fix both NUMA migration and compaction. [mgorman@suse.de: fix build] Signed-off-by: Rik van Riel <riel@redhat.com> Signed-off-by: Mel Gorman <mgorman@suse.de> Cc: Alex Thorlton <athorlton@sgi.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: numa: avoid unnecessary disruption of NUMA hinting during migrationMel Gorman2013-12-181-6/+16
| | | | | | | | | | | | | | do_huge_pmd_numa_page() handles the case where there is parallel THP migration. However, by the time it is checked the NUMA hinting information has already been disrupted. This patch adds an earlier check with some helpers. Signed-off-by: Mel Gorman <mgorman@suse.de> Reviewed-by: Rik van Riel <riel@redhat.com> Cc: Alex Thorlton <athorlton@sgi.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: numa: clear numa hinting information on mprotectMel Gorman2013-12-181-0/+2
| | | | | | | | | | | | | On a protection change it is no longer clear if the page should be still accessible. This patch clears the NUMA hinting fault bits on a protection change. Signed-off-by: Mel Gorman <mgorman@suse.de> Reviewed-by: Rik van Riel <riel@redhat.com> Cc: Alex Thorlton <athorlton@sgi.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: numa: ensure anon_vma is locked to prevent parallel THP splitsMel Gorman2013-12-181-0/+7
| | | | | | | | | | | | | | The anon_vma lock prevents parallel THP splits and any associated complexity that arises when handling splits during THP migration. This patch checks if the lock was successfully acquired and bails from THP migration if it failed for any reason. Signed-off-by: Mel Gorman <mgorman@suse.de> Reviewed-by: Rik van Riel <riel@redhat.com> Cc: Alex Thorlton <athorlton@sgi.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: numa: do not clear PMD during PTE update scanMel Gorman2013-12-181-1/+1
| | | | | | | | | | | | | | If the PMD is flushed then a parallel fault in handle_mm_fault() will enter the pmd_none and do_huge_pmd_anonymous_page() path where it'll attempt to insert a huge zero page. This is wasteful so the patch avoids clearing the PMD when setting pmd_numa. Signed-off-by: Mel Gorman <mgorman@suse.de> Reviewed-by: Rik van Riel <riel@redhat.com> Cc: Alex Thorlton <athorlton@sgi.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: numa: serialise parallel get_user_page against THP migrationMel Gorman2013-12-181-8/+16
| | | | | | | | | | | | | | | | | | | | | | | | Base pages are unmapped and flushed from cache and TLB during normal page migration and replaced with a migration entry that causes any parallel NUMA hinting fault or gup to block until migration completes. THP does not unmap pages due to a lack of support for migration entries at a PMD level. This allows races with get_user_pages and get_user_pages_fast which commit 3f926ab945b6 ("mm: Close races between THP migration and PMD numa clearing") made worse by introducing a pmd_clear_flush(). This patch forces get_user_page (fast and normal) on a pmd_numa page to go through the slow get_user_page path where it will serialise against THP migration and properly account for the NUMA hinting fault. On the migration side the page table lock is taken for each PTE update. Signed-off-by: Mel Gorman <mgorman@suse.de> Reviewed-by: Rik van Riel <riel@redhat.com> Cc: Alex Thorlton <athorlton@sgi.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* thp: move preallocated PTE page table on move_huge_pmd()Kirill A. Shutemov2013-12-121-1/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Andrey Wagin reported crash on VM_BUG_ON() in pgtable_pmd_page_dtor() with fallowing backtrace: free_pgd_range+0x2bf/0x410 free_pgtables+0xce/0x120 unmap_region+0xe0/0x120 do_munmap+0x249/0x360 move_vma+0x144/0x270 SyS_mremap+0x3b9/0x510 system_call_fastpath+0x16/0x1b The crash can be reproduce with this test case: #define _GNU_SOURCE #include <sys/mman.h> #include <stdio.h> #include <unistd.h> #define MB (1024 * 1024UL) #define GB (1024 * MB) int main(int argc, char **argv) { char *p; int i; p = mmap((void *) GB, 10 * MB, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS | MAP_FIXED, -1, 0); for (i = 0; i < 10 * MB; i += 4096) p[i] = 1; mremap(p, 10 * MB, 10 * MB, MREMAP_FIXED | MREMAP_MAYMOVE, 2 * GB); return 0; } Due to split PMD lock, we now store preallocated PTE tables for THP pages per-PMD table. It means we need to move them to other PMD table if huge PMD moved there. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Reported-by: Andrey Vagin <avagin@openvz.org> Tested-by: Andrey Vagin <avagin@openvz.org> Reviewed-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: convert the rest to new page table lock apiKirill A. Shutemov2013-11-151-48/+60
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Only trivial cases left. Let's convert them altogether. Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Tested-by: Alex Thorlton <athorlton@sgi.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: "Eric W . Biederman" <ebiederm@xmission.com> Cc: "Paul E . McKenney" <paulmck@linux.vnet.ibm.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Andi Kleen <ak@linux.intel.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Dave Jones <davej@redhat.com> Cc: David Howells <dhowells@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Kees Cook <keescook@chromium.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Robin Holt <robinmholt@gmail.com> Cc: Sedat Dilek <sedat.dilek@gmail.com> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm, thp: move ptl taking inside page_check_address_pmd()Kirill A. Shutemov2013-11-151-16/+27
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | With split page table lock we can't know which lock we need to take before we find the relevant pmd. Let's move lock taking inside the function. Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Tested-by: Alex Thorlton <athorlton@sgi.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: "Eric W . Biederman" <ebiederm@xmission.com> Cc: "Paul E . McKenney" <paulmck@linux.vnet.ibm.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Andi Kleen <ak@linux.intel.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Dave Jones <davej@redhat.com> Cc: David Howells <dhowells@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Kees Cook <keescook@chromium.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Robin Holt <robinmholt@gmail.com> Cc: Sedat Dilek <sedat.dilek@gmail.com> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm, thp: change pmd_trans_huge_lock() to return taken lockKirill A. Shutemov2013-11-151-13/+27
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | With split ptlock it's important to know which lock pmd_trans_huge_lock() took. This patch adds one more parameter to the function to return the lock. In most places migration to new api is trivial. Exception is move_huge_pmd(): we need to take two locks if pmd tables are different. Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Tested-by: Alex Thorlton <athorlton@sgi.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: "Eric W . Biederman" <ebiederm@xmission.com> Cc: "Paul E . McKenney" <paulmck@linux.vnet.ibm.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Andi Kleen <ak@linux.intel.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Dave Jones <davej@redhat.com> Cc: David Howells <dhowells@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Kees Cook <keescook@chromium.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Robin Holt <robinmholt@gmail.com> Cc: Sedat Dilek <sedat.dilek@gmail.com> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: convert mm->nr_ptes to atomic_long_tKirill A. Shutemov2013-11-151-5/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | With split page table lock for PMD level we can't hold mm->page_table_lock while updating nr_ptes. Let's convert it to atomic_long_t to avoid races. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Tested-by: Alex Thorlton <athorlton@sgi.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: "Eric W . Biederman" <ebiederm@xmission.com> Cc: "Paul E . McKenney" <paulmck@linux.vnet.ibm.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Andi Kleen <ak@linux.intel.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Dave Jones <davej@redhat.com> Cc: David Howells <dhowells@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Kees Cook <keescook@chromium.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Robin Holt <robinmholt@gmail.com> Cc: Sedat Dilek <sedat.dilek@gmail.com> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: thp: khugepaged: add policy for finding target nodeBob Liu2013-11-131-9/+44
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Khugepaged will scan/free HPAGE_PMD_NR normal pages and replace with a hugepage which is allocated from the node of the first scanned normal page, but this policy is too rough and may end with unexpected result to upper users. The problem is the original page-balancing among all nodes will be broken after hugepaged started. Thinking about the case if the first scanned normal page is allocated from node A, most of other scanned normal pages are allocated from node B or C.. But hugepaged will always allocate hugepage from node A which will cause extra memory pressure on node A which is not the situation before khugepaged started. This patch try to fix this problem by making khugepaged allocate hugepage from the node which have max record of scaned normal pages hit, so that the effect to original page-balancing can be minimized. The other problem is if normal scanned pages are equally allocated from Node A,B and C, after khugepaged started Node A will still suffer extra memory pressure. Andrew Davidoff reported a related issue several days ago. He wanted his application interleaving among all nodes and "numactl --interleave=all ./test" was used to run the testcase, but the result wasn't not as expected. cat /proc/2814/numa_maps: 7f50bd440000 interleave:0-3 anon=51403 dirty=51403 N0=435 N1=435 N2=435 N3=50098 The end result showed that most pages are from Node3 instead of interleave among node0-3 which was unreasonable. This patch also fix this issue by allocating hugepage round robin from all nodes have the same record, after this patch the result was as expected: 7f78399c0000 interleave:0-3 anon=51403 dirty=51403 N0=12723 N1=12723 N2=13235 N3=12722 The simple testcase is like this: int main() { char *p; int i; int j; for (i=0; i < 200; i++) { p = (char *)malloc(1048576); printf("malloc done\n"); if (p == 0) { printf("Out of memory\n"); return 1; } for (j=0; j < 1048576; j++) { p[j] = 'A'; } printf("touched memory\n"); sleep(1); } printf("enter sleep\n"); while(1) { sleep(100); } } [akpm@linux-foundation.org: make last_khugepaged_target_node local to khugepaged_find_target_node()] Reported-by: Andrew Davidoff <davidoff@qedmf.net> Tested-by: Andrew Davidoff <davidoff@qedmf.net> Signed-off-by: Bob Liu <bob.liu@oracle.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Mel Gorman <mel@csn.ul.ie> Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Cc: Wanpeng Li <liwanp@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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