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2014-12-22Revert "mm/memory.c: share the i_mmap_rwsem"Kirill A. Shutemov1-2/+2
This reverts commit c8475d144abb1e62958cc5ec281d2a9e161c1946. There are several[1][2] of bug reports which points to this commit as potential cause[3]. Let's revert it until we figure out what's going on. [1] https://lkml.org/lkml/2014/11/14/342 [2] https://lkml.org/lkml/2014/12/22/213 [3] https://lkml.org/lkml/2014/12/9/741 Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Reported-by: Sasha Levin <sasha.levin@oracle.com> Acked-by: Davidlohr Bueso <dave@stgolabs.net> Cc: Hugh Dickins <hughd@google.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: Mel Gorman <mgorman@suse.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-20Merge tag 'for-linus' of ↵Linus Torvalds3-3/+13
git://git.kernel.org/pub/scm/linux/kernel/git/borntraeger/linux Pull ACCESS_ONCE cleanup preparation from Christian Borntraeger: "kernel: Provide READ_ONCE and ASSIGN_ONCE As discussed on LKML http://marc.info/?i=54611D86.4040306%40de.ibm.com ACCESS_ONCE might fail with specific compilers for non-scalar accesses. Here is a set of patches to tackle that problem. The first patch introduce READ_ONCE and ASSIGN_ONCE. If the data structure is larger than the machine word size memcpy is used and a warning is emitted. The next patches fix up several in-tree users of ACCESS_ONCE on non-scalar types. This does not yet contain a patch that forces ACCESS_ONCE to work only on scalar types. This is targetted for the next merge window as Linux next already contains new offenders regarding ACCESS_ONCE vs. non-scalar types" * tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/borntraeger/linux: s390/kvm: REPLACE barrier fixup with READ_ONCE arm/spinlock: Replace ACCESS_ONCE with READ_ONCE arm64/spinlock: Replace ACCESS_ONCE READ_ONCE mips/gup: Replace ACCESS_ONCE with READ_ONCE x86/gup: Replace ACCESS_ONCE with READ_ONCE x86/spinlock: Replace ACCESS_ONCE with READ_ONCE mm: replace ACCESS_ONCE with READ_ONCE or barriers kernel: Provide READ_ONCE and ASSIGN_ONCE
2014-12-19Merge branch 'for-linus' of ↵Linus Torvalds4-28/+2
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull vfs pile #3 from Al Viro: "Assorted fixes and patches from the last cycle" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: [regression] chunk lost from bd9b51 vfs: make mounts and mountstats honor root dir like mountinfo does vfs: cleanup show_mountinfo init: fix read-write root mount unfuck binfmt_misc.c (broken by commit e6084d4) vm_area_operations: kill ->migrate() new helper: iter_is_iovec() move_extent_per_page(): get rid of unused w_flags lustre: get rid of playing with ->fs btrfs: filp_open() returns ERR_PTR() on failure, not NULL...
2014-12-18mm/zsmalloc: adjust order of functionsGanesh Mahendran1-187/+187
Currently functions in zsmalloc.c does not arranged in a readable and reasonable sequence. With the more and more functions added, we may meet below inconvenience. For example: Current functions: void zs_init() { } static void get_maxobj_per_zspage() { } Then I want to add a func_1() which is called from zs_init(), and this new added function func_1() will used get_maxobj_per_zspage() which is defined below zs_init(). void func_1() { get_maxobj_per_zspage() } void zs_init() { func_1() } static void get_maxobj_per_zspage() { } This will cause compiling issue. So we must add a declaration: static void get_maxobj_per_zspage(); before func_1() if we do not put get_maxobj_per_zspage() before func_1(). In addition, puting module_[init|exit] functions at the bottom of the file conforms to our habit. So, this patch ajusts function sequence as: /* helper functions */ ... obj_location_to_handle() ... /* Some exported functions */ ... zs_map_object() zs_unmap_object() zs_malloc() zs_free() zs_init() zs_exit() Signed-off-by: Ganesh Mahendran <opensource.ganesh@gmail.com> Cc: Nitin Gupta <ngupta@vflare.org> Acked-by: Minchan Kim <minchan@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-18mm/memory.c:do_shared_fault(): add commentAndrew Morton1-0/+6
Belatedly document the changes in commit f0c6d4d295e4 ("mm: introduce do_shared_fault() and drop do_fault()"). Cc: Andi Kleen <ak@linux.intel.com> Cc: Bob Liu <lliubbo@gmail.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: "Kirill A. Shutemov" <kirill@shutemov.name> Cc: Matthew Wilcox <matthew.r.wilcox@intel.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Rik van Riel <riel@redhat.com> Cc: Sasha Levin <sasha.levin@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-18mm: cma: split cma-reserved in dmesg logPintu Kumar2-2/+5
When the system boots up, in the dmesg logs we can see the memory statistics along with total reserved as below. Memory: 458840k/458840k available, 65448k reserved, 0K highmem When CMA is enabled, still the total reserved memory remains the same. However, the CMA memory is not considered as reserved. But, when we see /proc/meminfo, the CMA memory is part of free memory. This creates confusion. This patch corrects the problem by properly subtracting the CMA reserved memory from the total reserved memory in dmesg logs. Below is the dmesg snapshot from an arm based device with 512MB RAM and 12MB single CMA region. Before this change: Memory: 458840k/458840k available, 65448k reserved, 0K highmem After this change: Memory: 458840k/458840k available, 53160k reserved, 12288k cma-reserved, 0K highmem Signed-off-by: Pintu Kumar <pintu.k@samsung.com> Signed-off-by: Vishnu Pratap Singh <vishnu.ps@samsung.com> Acked-by: Michal Nazarewicz <mina86@mina86.com> Cc: Rafael Aquini <aquini@redhat.com> Cc: Jerome Marchand <jmarchan@redhat.com> Cc: Marek Szyprowski <m.szyprowski@samsung.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-18mm/mempolicy.c: remove unnecessary is_valid_nodemask()Zhihui Zhang1-8/+2
When nodes is true, nsc->mask2 has already been filtered by nsc->mask1, which has already factored in node_states[N_MEMORY]. Signed-off-by: Zhihui Zhang <zzhsuny@gmail.com> Cc: Mel Gorman <mel@csn.ul.ie> Cc: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-18mm: replace ACCESS_ONCE with READ_ONCE or barriersChristian Borntraeger3-3/+13
ACCESS_ONCE does not work reliably on non-scalar types. For example gcc 4.6 and 4.7 might remove the volatile tag for such accesses during the SRA (scalar replacement of aggregates) step (https://gcc.gnu.org/bugzilla/show_bug.cgi?id=58145) Let's change the code to access the page table elements with READ_ONCE that does implicit scalar accesses for the gup code. mm_find_pmd is tricky, because m68k and sparc(32bit) define pmd_t as array of longs. This code requires just that the pmd_present and pmd_trans_huge check are done on the same value, so a barrier is sufficent. A similar case is in handle_pte_fault. On ppc44x the word size is 32 bit, but a pte is 64 bit. A barrier is ok as well. Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Cc: linux-mm@kvack.org Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2014-12-17mmu_gather: fix over-eager tlb_flush_mmu_free() callingLinus Torvalds1-3/+3
Dave Hansen reports that commit fb7332a9fedf ("mmu_gather: move minimal range calculations into generic code") caused a performance problem: "tlb_finish_mmu() goes up about 9x in the profiles (~0.4%->3.6%) and tlb_flush_mmu_free() takes about 3.1% of CPU time with the patch applied, but does not show up at all on the commit before" and the reason is that Will moved the test for whether we need to flush from tlb_flush_mmu() into tlb_flush_mmu_tlbonly(). But that meant that tlb_flush_mmu_free() basically lost that check. Move it back into tlb_flush_mmu() where it belongs, so that it covers both tlb_flush_mmu_tlbonly() _and_ tlb_flush_mmu_free(). Reported-and-tested-by: Dave Hansen <dave@sr71.net> Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-17vm_area_operations: kill ->migrate()Al Viro2-26/+0
the only instance this method has ever grown was one in kernfs - one that call ->migrate() of another vm_ops if it exists. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-12-17new helper: iter_is_iovec()Al Viro2-2/+2
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-12-16Merge branch 'for-3.19' of git://linux-nfs.org/~bfields/linuxLinus Torvalds1-1/+1
Pull nfsd updates from Bruce Fields: "A comparatively quieter cycle for nfsd this time, but still with two larger changes: - RPC server scalability improvements from Jeff Layton (using RCU instead of a spinlock to find idle threads). - server-side NFSv4.2 ALLOCATE/DEALLOCATE support from Anna Schumaker, enabling fallocate on new clients" * 'for-3.19' of git://linux-nfs.org/~bfields/linux: (32 commits) nfsd4: fix xdr4 count of server in fs_location4 nfsd4: fix xdr4 inclusion of escaped char sunrpc/cache: convert to use string_escape_str() sunrpc: only call test_bit once in svc_xprt_received fs: nfsd: Fix signedness bug in compare_blob sunrpc: add some tracepoints around enqueue and dequeue of svc_xprt sunrpc: convert to lockless lookup of queued server threads sunrpc: fix potential races in pool_stats collection sunrpc: add a rcu_head to svc_rqst and use kfree_rcu to free it sunrpc: require svc_create callers to pass in meaningful shutdown routine sunrpc: have svc_wake_up only deal with pool 0 sunrpc: convert sp_task_pending flag to use atomic bitops sunrpc: move rq_cachetype field to better optimize space sunrpc: move rq_splice_ok flag into rq_flags sunrpc: move rq_dropme flag into rq_flags sunrpc: move rq_usedeferral flag to rq_flags sunrpc: move rq_local field to rq_flags sunrpc: add a generic rq_flags field to svc_rqst and move rq_secure to it nfsd: minor off by one checks in __write_versions() sunrpc: release svc_pool_map reference when serv allocation fails ...
2014-12-15Merge branch 'drm-next' of git://people.freedesktop.org/~airlied/linuxLinus Torvalds8-11/+44
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 ...
2014-12-14Merge git://git.kvack.org/~bcrl/aio-nextLinus Torvalds1-1/+2
Pull aio updates from Benjamin LaHaise. * git://git.kvack.org/~bcrl/aio-next: aio: Skip timer for io_getevents if timeout=0 aio: Make it possible to remap aio ring
2014-12-13aio: Make it possible to remap aio ringPavel Emelyanov1-1/+2
There are actually two issues this patch addresses. Let me start with the one I tried to solve in the beginning. So, in the checkpoint-restore project (criu) we try to dump tasks' state and restore one back exactly as it was. One of the tasks' state bits is rings set up with io_setup() call. There's (almost) no problems in dumping them, there's a problem restoring them -- if I dump a task with aio ring originally mapped at address A, I want to restore one back at exactly the same address A. Unfortunately, the io_setup() does not allow for that -- it mmaps the ring at whatever place mm finds appropriate (it calls do_mmap_pgoff() with zero address and without the MAP_FIXED flag). To make restore possible I'm going to mremap() the freshly created ring into the address A (under which it was seen before dump). The problem is that the ring's virtual address is passed back to the user-space as the context ID and this ID is then used as search key by all the other io_foo() calls. Reworking this ID to be just some integer doesn't seem to work, as this value is already used by libaio as a pointer using which this library accesses memory for aio meta-data. So, to make restore work we need to make sure that a) ring is mapped at desired virtual address b) kioctx->user_id matches this value Having said that, the patch makes mremap() on aio region update the kioctx's user_id and mmap_base values. Here appears the 2nd issue I mentioned in the beginning of this mail. If (regardless of the C/R dances I do) someone creates an io context with io_setup(), then mremap()-s the ring and then destroys the context, the kill_ioctx() routine will call munmap() on wrong (old) address. This will result in a) aio ring remaining in memory and b) some other vma get unexpectedly unmapped. What do you think? Signed-off-by: Pavel Emelyanov <xemul@parallels.com> Acked-by: Dmitry Monakhov <dmonakhov@openvz.org> Signed-off-by: Benjamin LaHaise <bcrl@kvack.org>
2014-12-13mm/cma: make kmemleak ignore CMA regionsThierry Reding1-0/+6
kmemleak will add allocations as objects to a pool. The memory allocated for each object in this pool is periodically searched for pointers to other allocated objects. This only works for memory that is mapped into the kernel's virtual address space, which happens not to be the case for most CMA regions. Furthermore, CMA regions are typically used to store data transferred to or from a device and therefore don't contain pointers to other objects. Without this, the kernel crashes on the first execution of the scan_gray_list() because it tries to access highmem. Perhaps a more appropriate fix would be to reject any object that can't map to a kernel virtual address? [akpm@linux-foundation.org: add comment] [akpm@linux-foundation.org: fix comment, per Catalin] [sfr@canb.auug.org.au: include linux/io.h for phys_to_virt()] Signed-off-by: Thierry Reding <treding@nvidia.com> Cc: Michal Nazarewicz <mina86@mina86.com> Cc: Marek Szyprowski <m.szyprowski@samsung.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-13slub: fix cpuset check in get_any_partialVladimir Davydov1-2/+1
If we fail to allocate from the current node's stock, we look for free objects on other nodes before calling the page allocator (see get_any_partial). While checking other nodes we respect cpuset constraints by calling cpuset_zone_allowed. We enforce hardwall check. As a result, we will fallback to the page allocator even if there are some pages cached on other nodes, but the current cpuset doesn't have them set. However, the page allocator uses softwall check for kernel allocations, so it may allocate from one of the other nodes in this case. Therefore we should use softwall cpuset check in get_any_partial to conform with the cpuset check in the page allocator. Signed-off-by: Vladimir Davydov <vdavydov@parallels.com> Acked-by: Zefan Li <lizefan@huawei.com> Acked-by: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Tejun Heo <tj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-13slab: fix cpuset check in fallback_allocVladimir Davydov1-1/+1
fallback_alloc is called on kmalloc if the preferred node doesn't have free or partial slabs and there's no pages on the node's free list (GFP_THISNODE allocations fail). Before invoking the reclaimer it tries to locate a free or partial slab on other allowed nodes' lists. While iterating over the preferred node's zonelist it skips those zones which hardwall cpuset check returns false for. That means that for a task bound to a specific node using cpusets fallback_alloc will always ignore free slabs on other nodes and go directly to the reclaimer, which, however, may allocate from other nodes if cpuset.mem_hardwall is unset (default). As a result, we may get lists of free slabs grow without bounds on other nodes, which is bad, because inactive slabs are only evicted by cache_reap at a very slow rate and cannot be dropped forcefully. To reproduce the issue, run a process that will walk over a directory tree with lots of files inside a cpuset bound to a node that constantly experiences memory pressure. Look at num_slabs vs active_slabs growth as reported by /proc/slabinfo. To avoid this we should use softwall cpuset check in fallback_alloc. Signed-off-by: Vladimir Davydov <vdavydov@parallels.com> Acked-by: Zefan Li <lizefan@huawei.com> Acked-by: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Tejun Heo <tj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-13mm/zbud: init user ops only when it is neededHeesub Shin1-1/+1
When zbud is initialized through the zpool wrapper, pool->ops which points to user-defined operations is always set regardless of whether it is specified from the upper layer. This causes zbud_reclaim_page() to iterate its loop for evicting pool pages out without any gain. This patch sets the user-defined ops only when it is needed, so that zbud_reclaim_page() can bail out the reclamation loop earlier if there is no user-defined operations specified. Signed-off-by: Heesub Shin <heesub.shin@samsung.com> Acked-by: Dan Streetman <ddstreet@ieee.org> Cc: Seth Jennings <sjennings@variantweb.net> Cc: Sunae Seo <sunae.seo@samsung.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-13mm/zswap: delete unnecessary check before calling free_percpu()Markus Elfring1-2/+1
free_percpu() tests whether its argument is NULL and then returns immediately. Thus the test around the call is not needed. This issue was detected by using the Coccinelle software. Signed-off-by: Markus Elfring <elfring@users.sourceforge.net> Cc: Seth Jennings <sjennings@variantweb.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-13mm/zswap: add __init to some functions in zswapMahendran Ganesh1-3/+3
zswap_cpu_init/zswap_comp_exit/zswap_entry_cache_create is only called by __init init_zswap() Signed-off-by: Mahendran Ganesh <opensource.ganesh@gmail.com> Cc: Seth Jennings <sjennings@variantweb.net> Cc: Dan Streetman <ddstreet@ieee.org> Cc: Minchan Kim <minchan@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-13mm/zsmalloc: allocate exactly size of struct zs_poolGanesh Mahendran1-3/+2
In zs_create_pool(), we allocate memory more then sizeof(struct zs_pool) ovhd_size = roundup(sizeof(*pool), PAGE_SIZE); This patch allocate memory of exactly needed size. Signed-off-by: Ganesh Mahendran <opensource.ganesh@gmail.com> Acked-by: Minchan Kim <minchan@kernel.org> Cc: Nitin Gupta <ngupta@vflare.org> Cc: Dan Streetman <ddstreet@ieee.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-13mm/zsmalloc: avoid duplicate assignment of prev_classGanesh Mahendran1-5/+4
In zs_create_pool(), prev_class is assigned (ZS_SIZE_CLASSES - 1) times. And the prev_class only references to the previous size_class. So we do not need unnecessary assignement. This patch assigns *prev_class* when a new size_class structure is allocated and uses prev_class to check whether the first class has been allocated. [akpm@linux-foundation.org: remove now-unused ZS_SIZE_CLASSES] Signed-off-by: Ganesh Mahendran <opensource.ganesh@gmail.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Nitin Gupta <ngupta@vflare.org> Reviewed-by: Dan Streetman <ddstreet@ieee.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-13mm/zsmalloc: support allocating obj with size of ZS_MAX_ALLOC_SIZEMahendran Ganesh1-6/+32
I sent a patch [1] for unnecessary check in zsmalloc. And Minchan Kim found zsmalloc even does not support allocating an obj with the size of ZS_MAX_ALLOC_SIZE in some situations. For example: In system with 64KB PAGE_SIZE and 32 bit of physical addr. Then: ZS_MIN_ALLOC_SIZE is 32 bytes which is calculated by: MAX(32, (ZS_MAX_PAGES_PER_ZSPAGE << PAGE_SHIFT >> OBJ_INDEX_BITS)) ZS_MAX_ALLOC_SIZE is 64KB(in current code, is PAGE_SIZE) ZS_SIZE_CLASS_DELTA is 256 bytes So, ZS_SIZE_CLASSES = (ZS_MAX_ALLOC_SIZE - ZS_MIN_ALLOC_SIZE) / ZS_SIZE_CLASS_DELTA + 1 = 256 In zs_create_pool(), the max size obj which can be allocated will be: ZS_MIN_ALLOC_SIZE + i * ZS_SIZE_CLASS_DELTA = 32 + 255*256 = 65312 We can see that 65312 < 65536 (ZS_MAX_ALLOC_SIZE). So we can NOT allocate objs with size ZS_MAX_ALLOC_SIZE(65536) which we promise upper users we can do. [1] http://lkml.iu.edu/hypermail/linux/kernel/1411.2/03835.html [2] http://lkml.iu.edu/hypermail/linux/kernel/1411.2/04534.html This patch fixes this issue by dynamiclly calculating zs_size_classes when module is loaded, allocates buffer with size ZS_MAX_ALLOC_SIZE. Then the max obj(size is ZS_MAX_ALLOC_SIZE) can be stored in it. [akpm@linux-foundation.org: restore ZS_SIZE_CLASSES to fix bisectability] Signed-off-by: Mahendran Ganesh <opensource.ganesh@gmail.com> Suggested-by: Minchan Kim <minchan@kernel.org> Cc: Nitin Gupta <ngupta@vflare.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-13zsmalloc: correct fragile [kmap|kunmap]_atomic useMinchan Kim1-9/+12
The kunmap_atomic should use virtual address getting by kmap_atomic. However, some pieces of code in zsmalloc uses modified address, not the one got by kmap_atomic for kunmap_atomic. It's okay for working because zsmalloc modifies the address inner PAGE_SIZE bounday so it works with current kmap_atomic's implementation. But it's still fragile with potential changing of kmap_atomic so let's correct it. I got a subtle bug when I implemented a new feature of zsmalloc (compaction) due to a link's mishandling (the link was over page boundary). Although it was totally my mistake, it took a while to find the cause because an unpredictable kmapped address was unmapped causing an almost random crash. Signed-off-by: Minchan Kim <minchan@kernel.org> Cc: Nitin Gupta <ngupta@vflare.org> Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: Dan Streetman <ddstreet@ieee.org> Cc: Seth Jennings <sjennings@variantweb.net> Cc: Jerome Marchand <jmarchan@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-13zsmalloc: fix zs_init cpu notifier error handlingSergey Senozhatsky1-15/+24
Mahendran Ganesh reported that zpool-enabled zsmalloc should not call zpool_unregister_driver() from zs_init() if cpu notifier registration has failed, because error handling is performed before we register the driver via zpool_register_driver() call. Factor out cpu notifier registration and unregistration code and fix zs_init() error handling. link: http://lkml.iu.edu//hypermail/linux/kernel/1411.1/04156.html [akpm@linux-foundation.org: squash bogus gcc warning] [akpm@linux-foundation.org: use __init and __exit] Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Reported-by: Mahendran Ganesh <opensource.ganesh@gmail.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Nitin Gupta <ngupta@vflare.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-13zsmalloc: merge size_class to reduce fragmentationJoonsoo Kim1-14/+66
zsmalloc has many size_classes to reduce fragmentation and they are in 16 bytes unit, for example, 16, 32, 48, etc., if PAGE_SIZE is 4096. And, zsmalloc has constraint that each zspage has 4 pages at maximum. In this situation, we can see interesting aspect. Let's think about size_class for 1488, 1472, ..., 1376. To prevent external fragmentation, they uses 4 pages per zspage and so all they can contain 11 objects at maximum. 16384 (4096 * 4) = 1488 * 11 + remains 16384 (4096 * 4) = 1472 * 11 + remains 16384 (4096 * 4) = ... 16384 (4096 * 4) = 1376 * 11 + remains It means that they have same characteristics and classification between them isn't needed. If we use one size_class for them, we can reduce fragementation and save some memory since both the 1488 and 1472 sized classes can only fit 11 objects into 4 pages, and an object that's 1472 bytes can fit into an object that's 1488 bytes, merging these classes to always use objects that are 1488 bytes will reduce the total number of size classes. And reducing the total number of size classes reduces overall fragmentation, because a wider range of compressed pages can fit into a single size class, leaving less unused objects in each size class. For this purpose, this patch implement size_class merging. If there is size_class that have same pages_per_zspage and same number of objects per zspage with previous size_class, we don't create new size_class. Instead, we use previous, same characteristic size_class. With this way, above example sizes (1488, 1472, ..., 1376) use just one size_class so we can get much more memory utilization. Below is result of my simple test. TEST ENV: EXT4 on zram, mount with discard option WORKLOAD: untar kernel source code, remove directory in descending order in size. (drivers arch fs sound include net Documentation firmware kernel tools) Each line represents orig_data_size, compr_data_size, mem_used_total, fragmentation overhead (mem_used - compr_data_size) and overhead ratio (overhead to compr_data_size), respectively, after untar and remove operation is executed. * untar-nomerge.out orig_size compr_size used_size overhead overhead_ratio 525.88MB 199.16MB 210.23MB 11.08MB 5.56% 288.32MB 97.43MB 105.63MB 8.20MB 8.41% 177.32MB 61.12MB 69.40MB 8.28MB 13.55% 146.47MB 47.32MB 56.10MB 8.78MB 18.55% 124.16MB 38.85MB 48.41MB 9.55MB 24.58% 103.93MB 31.68MB 40.93MB 9.25MB 29.21% 84.34MB 22.86MB 32.72MB 9.86MB 43.13% 66.87MB 14.83MB 23.83MB 9.00MB 60.70% 60.67MB 11.11MB 18.60MB 7.49MB 67.48% 55.86MB 8.83MB 16.61MB 7.77MB 88.03% 53.32MB 8.01MB 15.32MB 7.31MB 91.24% * untar-merge.out orig_size compr_size used_size overhead overhead_ratio 526.23MB 199.18MB 209.81MB 10.64MB 5.34% 288.68MB 97.45MB 104.08MB 6.63MB 6.80% 177.68MB 61.14MB 66.93MB 5.79MB 9.47% 146.83MB 47.34MB 52.79MB 5.45MB 11.51% 124.52MB 38.87MB 44.30MB 5.43MB 13.96% 104.29MB 31.70MB 36.83MB 5.13MB 16.19% 84.70MB 22.88MB 27.92MB 5.04MB 22.04% 67.11MB 14.83MB 19.26MB 4.43MB 29.86% 60.82MB 11.10MB 14.90MB 3.79MB 34.17% 55.90MB 8.82MB 12.61MB 3.79MB 42.97% 53.32MB 8.01MB 11.73MB 3.73MB 46.53% As you can see above result, merged one has better utilization (overhead ratio, 5th column) and uses less memory (mem_used_total, 3rd column). Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Nitin Gupta <ngupta@vflare.org> Cc: Jerome Marchand <jmarchan@redhat.com> Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Reviewed-by: Dan Streetman <ddstreet@ieee.org> Cc: Luigi Semenzato <semenzato@google.com> Cc: <juno.choi@lge.com> Cc: "seungho1.park" <seungho1.park@lge.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-13mm/memcontrol.c: remove unused mem_cgroup_lru_names_not_uptodate()Rickard Strandqvist1-5/+2
Remove unused mem_cgroup_lru_names_not_uptodate() and move BUILD_BUG_ON() to the beginning of memcg_stat_show(). This was partially found by using a static code analysis program called cppcheck. Signed-off-by: Rickard Strandqvist <rickard_strandqvist@spectrumdigital.se> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-13memcg: fix possible use-after-free in memcg_kmem_get_cache()Vladimir Davydov3-40/+27
Suppose task @t that belongs to a memory cgroup @memcg is going to allocate an object from a kmem cache @c. The copy of @c corresponding to @memcg, @mc, is empty. Then if kmem_cache_alloc races with the memory cgroup destruction we can access the memory cgroup's copy of the cache after it was destroyed: CPU0 CPU1 ---- ---- [ current=@t @mc->memcg_params->nr_pages=0 ] kmem_cache_alloc(@c): call memcg_kmem_get_cache(@c); proceed to allocation from @mc: alloc a page for @mc: ... move @t from @memcg destroy @memcg: mem_cgroup_css_offline(@memcg): memcg_unregister_all_caches(@memcg): kmem_cache_destroy(@mc) add page to @mc We could fix this issue by taking a reference to a per-memcg cache, but that would require adding a per-cpu reference counter to per-memcg caches, which would look cumbersome. Instead, let's take a reference to a memory cgroup, which already has a per-cpu reference counter, in the beginning of kmem_cache_alloc to be dropped in the end, and move per memcg caches destruction from css offline to css free. As a side effect, per-memcg caches will be destroyed not one by one, but all at once when the last page accounted to the memory cgroup is freed. This doesn't sound as a high price for code readability though. Note, this patch does add some overhead to the kmem_cache_alloc hot path, but it is pretty negligible - it's just a function call plus a per cpu counter decrement, which is comparable to what we already have in memcg_kmem_get_cache. Besides, it's only relevant if there are memory cgroups with kmem accounting enabled. I don't think we can find a way to handle this race w/o it, because alloc_page called from kmem_cache_alloc may sleep so we can't flush all pending kmallocs w/o reference counting. Signed-off-by: Vladimir Davydov <vdavydov@parallels.com> Acked-by: Christoph Lameter <cl@linux.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.cz> Cc: Pekka Enberg <penberg@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-13mm/memcontrol.c: fix defined but not used compiler warningMichele Curti1-1/+2
test_mem_cgroup_node_reclaimable() is used only when MAX_NUMNODES > 1, so move it into the compiler if statement [akpm@linux-foundation.org: clean up layout] Signed-off-by: Michele Curti <michele.curti@gmail.com> Acked-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>
2014-12-13mm: fadvise: document the fadvise(FADV_DONTNEED) behaviour for partial pagesMel Gorman1-1/+5
A random seek IO benchmark appeared to regress because of a change to readahead but the real problem was the benchmark. To ensure the IO request accesssed disk, it used fadvise(FADV_DONTNEED) on a block boundary (512K) but the hint is ignored by the kernel. This is correct but not necessarily obvious behaviour. As much as I dislike comment patches, the explanation for this behaviour predates current git history. Clarify why it behaves like this in case someone "fixes" fadvise or readahead for the wrong reasons. Signed-off-by: Mel Gorman <mgorman@suse.de> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-13mm/vmalloc.c: fix memory ordering bugDmitry Vyukov1-2/+2
Read memory barriers must follow the read operations. Signed-off-by: Dmitry Vyukov <dvyukov@google.com> Cc: Eric Dumazet <edumazet@google.com> Acked-by: Joonsoo Kim <iamjoonsoo.kim@lge.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-13oom: kill the insufficient and no longer needed PT_TRACE_EXIT checkOleg Nesterov1-8/+3
After the previous patch we can remove the PT_TRACE_EXIT check in oom_scan_process_thread(), it was added to handle the case when the coredumping was "frozen" by ptrace, but it doesn't really work. If nothing else, we would need to check all threads which could share the same ->mm to make it more or less correct. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Cc: Cong Wang <xiyou.wangcong@gmail.com> Cc: David Rientjes <rientjes@google.com> Acked-by: Michal Hocko <mhocko@suse.cz> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> Cc: Tejun Heo <tj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-13oom: don't assume that a coredumping thread will exit soonOleg Nesterov2-4/+4
oom_kill.c assumes that PF_EXITING task should exit and free the memory soon. This is wrong in many ways and one important case is the coredump. A task can sleep in exit_mm() "forever" while the coredumping sub-thread can need more memory. Change the PF_EXITING checks to take SIGNAL_GROUP_COREDUMP into account, we add the new trivial helper for that. Note: this is only the first step, this patch doesn't try to solve other problems. The SIGNAL_GROUP_COREDUMP check is obviously racy, a task can participate in coredump after it was already observed in PF_EXITING state, so TIF_MEMDIE (which also blocks oom-killer) still can be wrongly set. fatal_signal_pending() can be true because of SIGNAL_GROUP_COREDUMP so out_of_memory() and mem_cgroup_out_of_memory() shouldn't blindly trust it. And even the name/usage of the new helper is confusing, an exiting thread can only free its ->mm if it is the only/last task in thread group. [akpm@linux-foundation.org: add comment] Signed-off-by: Oleg Nesterov <oleg@redhat.com> Cc: Cong Wang <xiyou.wangcong@gmail.com> Acked-by: David Rientjes <rientjes@google.com> Acked-by: Michal Hocko <mhocko@suse.cz> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> Cc: Tejun Heo <tj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-13mm: remove the highmem zones' memmap in the highmem zoneZhong Hongbo1-10/+12
Since 01cefaef40c4 ("mm: provide more accurate estimation of pages occupied by memmap") allocate the pages from lowmem for the highmem zones' memmap. So It is not need to reserver the memmap's for the highmem. A 2G DDR3 for the arm platform: On node 0 totalpages: 524288 free_area_init_node: node 0, pgdat 80ccd380, node_mem_map 80d38000 DMA zone: 3568 pages used for memmap DMA zone: 0 pages reserved DMA zone: 456704 pages, LIFO batch:31 HighMem zone: 528 pages used for memmap HighMem zone: 67584 pages, LIFO batch:15 On node 0 totalpages: 524288 free_area_init_node: node 0, pgdat 80cd6f40, node_mem_map 80d42000 DMA zone: 3568 pages used for memmap DMA zone: 0 pages reserved DMA zone: 456704 pages, LIFO batch:31 HighMem zone: 67584 pages, LIFO batch:15 Signed-off-by: Hongbo Zhong <hongbo.zhong@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-13mm: unmapped page migration avoid unmap+remap overheadHugh Dickins1-10/+18
Page migration's __unmap_and_move(), and rmap's try_to_unmap(), were created for use on pages almost certainly mapped into userspace. But nowadays compaction often applies them to unmapped page cache pages: which may exacerbate contention on i_mmap_rwsem quite unnecessarily, since try_to_unmap_file() makes no preliminary page_mapped() check. Now check page_mapped() in __unmap_and_move(); and avoid repeating the same overhead in rmap_walk_file() - don't remove_migration_ptes() when we never inserted any. (The PageAnon(page) comment blocks now look even sillier than before, but clean that up on some other occasion. And note in passing that try_to_unmap_one() does not use a migration entry when PageSwapCache, so remove_migration_ptes() will then not update that swap entry to newpage pte: not a big deal, but something else to clean up later.) Davidlohr remarked in "mm,fs: introduce helpers around the i_mmap_mutex" conversion to i_mmap_rwsem, that "The biggest winner of these changes is migration": a part of the reason might be all of that unnecessary taking of i_mmap_mutex in page migration; and it's rather a shame that I didn't get around to sending this patch in before his - this one is much less useful after Davidlohr's conversion to rwsem, but still good. Signed-off-by: Hugh Dickins <hughd@google.com> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Rik van Riel <riel@redhat.com> Cc: Mel Gorman <mel@csn.ul.ie> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-13mm: vmscan: invoke slab shrinkers from shrink_zone()Johannes Weiner3-137/+96
The slab shrinkers are currently invoked from the zonelist walkers in kswapd, direct reclaim, and zone reclaim, all of which roughly gauge the eligible LRU pages and assemble a nodemask to pass to NUMA-aware shrinkers, which then again have to walk over the nodemask. This is redundant code, extra runtime work, and fairly inaccurate when it comes to the estimation of actually scannable LRU pages. The code duplication will only get worse when making the shrinkers cgroup-aware and requiring them to have out-of-band cgroup hierarchy walks as well. Instead, invoke the shrinkers from shrink_zone(), which is where all reclaimers end up, to avoid this duplication. Take the count for eligible LRU pages out of get_scan_count(), which considers many more factors than just the availability of swap space, like zone_reclaimable_pages() currently does. Accumulate the number over all visited lruvecs to get the per-zone value. Some nodes have multiple zones due to memory addressing restrictions. To avoid putting too much pressure on the shrinkers, only invoke them once for each such node, using the class zone of the allocation as the pivot zone. For now, this integrates the slab shrinking better into the reclaim logic and gets rid of duplicative invocations from kswapd, direct reclaim, and zone reclaim. It also prepares for cgroup-awareness, allowing memcg-capable shrinkers to be added at the lruvec level without much duplication of both code and runtime work. This changes kswapd behavior, which used to invoke the shrinkers for each zone, but with scan ratios gathered from the entire node, resulting in meaningless pressure quantities on multi-zone nodes. Zone reclaim behavior also changes. It used to shrink slabs until the same amount of pages were shrunk as were reclaimed from the LRUs. Now it merely invokes the shrinkers once with the zone's scan ratio, which makes the shrinkers go easier on caches that implement aging and would prefer feeding back pressure from recently used slab objects to unused LRU pages. [vdavydov@parallels.com: assure class zone is populated] Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Dave Chinner <david@fromorbit.com> Signed-off-by: Vladimir Davydov <vdavydov@parallels.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-13mm,vmacache: count number of system-wide flushesDavidlohr Bueso2-0/+3
These flushes deal with sequence number overflows, such as for long lived threads. These are rare, but interesting from a debugging PoV. As such, display the number of flushes when vmacache debugging is enabled. Signed-off-by: Davidlohr Bueso <dbueso@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-13mm/page_owner: correct owner information for early allocated pagesJoonsoo Kim1-2/+91
Extended memory to store page owner information is initialized some time later than that page allocator starts. Until initialization, many pages can be allocated and they have no owner information. This make debugging using page owner harder, so some fixup will be helpful. This patch fixes up this situation by setting fake owner information immediately after page extension is initialized. Information doesn't tell the right owner, but, at least, it can tell whether page is allocated or not, more correctly. On my testing, this patch catches 13343 early allocated pages, although they are mostly allocated from page extension feature. Anyway, after then, there is no page left that it is allocated and has no page owner flag. Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Dave Hansen <dave@sr71.net> Cc: Michal Nazarewicz <mina86@mina86.com> Cc: Jungsoo Son <jungsoo.son@lge.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-13mm/page_owner: keep track of page ownersJoonsoo Kim5-1/+338
This is the page owner tracking code which is introduced so far ago. It is resident on Andrew's tree, though, nobody tried to upstream so it remain as is. Our company uses this feature actively to debug memory leak or to find a memory hogger so I decide to upstream this feature. This functionality help us to know who allocates the page. When allocating a page, we store some information about allocation in extra memory. Later, if we need to know status of all pages, we can get and analyze it from this stored information. In previous version of this feature, extra memory is statically defined in struct page, but, in this version, extra memory is allocated outside of struct page. It enables us to turn on/off this feature at boottime without considerable memory waste. Although we already have tracepoint for tracing page allocation/free, using it to analyze page owner is rather complex. We need to enlarge the trace buffer for preventing overlapping until userspace program launched. And, launched program continually dump out the trace buffer for later analysis and it would change system behaviour with more possibility rather than just keeping it in memory, so bad for debug. Moreover, we can use page_owner feature further for various purposes. For example, we can use it for fragmentation statistics implemented in this patch. And, I also plan to implement some CMA failure debugging feature using this interface. I'd like to give the credit for all developers contributed this feature, but, it's not easy because I don't know exact history. Sorry about that. Below is people who has "Signed-off-by" in the patches in Andrew's tree. Contributor: Alexander Nyberg <alexn@dsv.su.se> Mel Gorman <mgorman@suse.de> Dave Hansen <dave@linux.vnet.ibm.com> Minchan Kim <minchan@kernel.org> Michal Nazarewicz <mina86@mina86.com> Andrew Morton <akpm@linux-foundation.org> Jungsoo Son <jungsoo.son@lge.com> Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Dave Hansen <dave@sr71.net> Cc: Michal Nazarewicz <mina86@mina86.com> Cc: Jungsoo Son <jungsoo.son@lge.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-13mm/nommu: use alloc_pages_exact() rather than its own implementationJoonsoo Kim1-22/+11
do_mmap_private() in nommu.c try to allocate physically contiguous pages with arbitrary size in some cases and we now have good abstract function to do exactly same thing, alloc_pages_exact(). So, change to use it. There is no functional change. This is the preparation step for support page owner feature accurately. Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Dave Hansen <dave@sr71.net> Cc: Michal Nazarewicz <mina86@mina86.com> Cc: Jungsoo Son <jungsoo.son@lge.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-13mm/debug-pagealloc: make debug-pagealloc boottime configurableJoonsoo Kim2-1/+27
Now, we have prepared to avoid using debug-pagealloc in boottime. So introduce new kernel-parameter to disable debug-pagealloc in boottime, and makes related functions to be disabled in this case. Only non-intuitive part is change of guard page functions. Because guard page is effective only if debug-pagealloc is enabled, turning off according to debug-pagealloc is reasonable thing to do. Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Dave Hansen <dave@sr71.net> Cc: Michal Nazarewicz <mina86@mina86.com> Cc: Jungsoo Son <jungsoo.son@lge.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-13mm/debug-pagealloc: prepare boottime configurable on/offJoonsoo Kim4-7/+73
Until now, debug-pagealloc needs extra flags in struct page, so we need to recompile whole source code when we decide to use it. This is really painful, because it takes some time to recompile and sometimes rebuild is not possible due to third party module depending on struct page. So, we can't use this good feature in many cases. Now, we have the page extension feature that allows us to insert extra flags to outside of struct page. This gets rid of third party module issue mentioned above. And, this allows us to determine if we need extra memory for this page extension in boottime. With these property, we can avoid using debug-pagealloc in boottime with low computational overhead in the kernel built with CONFIG_DEBUG_PAGEALLOC. This will help our development process greatly. This patch is the preparation step to achive above goal. debug-pagealloc originally uses extra field of struct page, but, after this patch, it will use field of struct page_ext. Because memory for page_ext is allocated later than initialization of page allocator in CONFIG_SPARSEMEM, we should disable debug-pagealloc feature temporarily until initialization of page_ext. This patch implements this. Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Dave Hansen <dave@sr71.net> Cc: Michal Nazarewicz <mina86@mina86.com> Cc: Jungsoo Son <jungsoo.son@lge.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-13mm/page_ext: resurrect struct page extending code for debuggingJoonsoo Kim4-0/+407
When we debug something, we'd like to insert some information to every page. For this purpose, we sometimes modify struct page itself. But, this has drawbacks. First, it requires re-compile. This makes us hesitate to use the powerful debug feature so development process is slowed down. And, second, sometimes it is impossible to rebuild the kernel due to third party module dependency. At third, system behaviour would be largely different after re-compile, because it changes size of struct page greatly and this structure is accessed by every part of kernel. Keeping this as it is would be better to reproduce errornous situation. This feature is intended to overcome above mentioned problems. This feature allocates memory for extended data per page in certain place rather than the struct page itself. This memory can be accessed by the accessor functions provided by this code. During the boot process, it checks whether allocation of huge chunk of memory is needed or not. If not, it avoids allocating memory at all. With this advantage, we can include this feature into the kernel in default and can avoid rebuild and solve related problems. Until now, memcg uses this technique. But, now, memcg decides to embed their variable to struct page itself and it's code to extend struct page has been removed. I'd like to use this code to develop debug feature, so this patch resurrect it. To help these things to work well, this patch introduces two callbacks for clients. One is the need callback which is mandatory if user wants to avoid useless memory allocation at boot-time. The other is optional, init callback, which is used to do proper initialization after memory is allocated. Detailed explanation about purpose of these functions is in code comment. Please refer it. Others are completely same with previous extension code in memcg. Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Dave Hansen <dave@sr71.net> Cc: Michal Nazarewicz <mina86@mina86.com> Cc: Jungsoo Son <jungsoo.son@lge.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-13mm/memcontrol.c: remove the unused arg in __memcg_kmem_get_cache()Zhang Zhen1-2/+1
The gfp was passed in but never used in this function. Signed-off-by: Zhang Zhen <zhenzhang.zhang@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-13mm: export find_extend_vma() and handle_mm_fault() for driver useJesse Barnes2-0/+3
This lets drivers like the AMD IOMMUv2 driver handle faults a bit more simply, rather than doing tricks with page refs and get_user_pages(). Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org> Cc: Oded Gabbay <oded.gabbay@amd.com> Cc: Joerg Roedel <jroedel@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-13hugetlb: hugetlb_register_all_nodes(): add __init markerLuiz Capitulino1-1/+1
This function is only called during initialization. Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com> Cc: Andi Kleen <andi@firstfloor.org> Acked-by: David Rientjes <rientjes@google.com> Cc: Rik van Riel <riel@redhat.com> Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Cc: Yinghai Lu <yinghai@kernel.org> Cc: Davidlohr Bueso <dave@stgolabs.net> Acked-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>
2014-12-13hugetlb: alloc_bootmem_huge_page(): use IS_ALIGNED()Luiz Capitulino1-1/+1
No reason to duplicate the code of an existing macro. Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com> Cc: Andi Kleen <andi@firstfloor.org> Acked-by: David Rientjes <rientjes@google.com> Cc: Rik van Riel <riel@redhat.com> Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Cc: Yinghai Lu <yinghai@kernel.org> Cc: Davidlohr Bueso <dave@stgolabs.net> Acked-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>
2014-12-13memcg: turn memcg_kmem_skip_account into a bit fieldVladimir Davydov1-33/+2
It isn't supposed to stack, so turn it into a bit-field to save 4 bytes on the task_struct. Also, remove the memcg_stop/resume_kmem_account helpers - it is clearer to set/clear the flag inline. Regarding the overwhelming comment to the helpers, which is removed by this patch too, we already have a compact yet accurate explanation in memcg_schedule_cache_create, no need in yet another one. Signed-off-by: Vladimir Davydov <vdavydov@parallels.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-13memcg: only check memcg_kmem_skip_account in __memcg_kmem_get_cacheVladimir Davydov1-28/+0
__memcg_kmem_get_cache can recurse if it calls kmalloc (which it does if the cgroup's kmem cache doesn't exist), because kmalloc may call __memcg_kmem_get_cache internally again. To avoid the recursion, we use the task_struct->memcg_kmem_skip_account flag. However, there's no need checking the flag in memcg_kmem_newpage_charge, because there's no way how this function could result in recursion, if called from memcg_kmem_get_cache. So let's remove the redundant code. Signed-off-by: Vladimir Davydov <vdavydov@parallels.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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