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* zswap: runtime enable/disableDan Streetman2015-06-252-9/+21
| | | | | | | | | | | | | | | | Change the "enabled" parameter to be configurable at runtime. Remove the enabled check from init(), and move it to the frontswap store() function; when enabled, pages will be stored, and when disabled, pages won't be stored. This is almost identical to Seth's patch from 2 years ago: http://lkml.iu.edu/hypermail/linux/kernel/1307.2/04289.html [akpm@linux-foundation.org: tweak documentation] Signed-off-by: Dan Streetman <ddstreet@ieee.org> Suggested-by: Seth Jennings <sjennings@variantweb.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* zram: check comp algorithm availability earlierSergey Senozhatsky2015-06-253-0/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | Improvement idea by Marcin Jabrzyk. comp_algorithm_store() silently accepts any supplied algorithm name, because zram performs algorithm availability check later, during the device configuration phase in disksize_store() and emits the following error: "zram: Cannot initialise %s compressing backend" this error line is somewhat generic and, besides, can indicate a failed attempt to allocate compression backend's working buffers. add algorithm availability check to comp_algorithm_store(): echo lzz > /sys/block/zram0/comp_algorithm -bash: echo: write error: Invalid argument Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Reported-by: Marcin Jabrzyk <m.jabrzyk@samsung.com> Acked-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>
* zram: cut trailing newline in algorithm nameSergey Senozhatsky2015-06-252-1/+9
| | | | | | | | | | | | | | | | | | | | | | | | Supplied sysfs values sometimes contain new-line symbols (echo vs. echo -n), which we also copy as a compression algorithm name. it works fine when we lookup for compression algorithm, because we use sysfs_streq() which takes care of new line symbols. however, it doesn't look nice when we print compression algorithm name if zcomp_create() failed: zram: Cannot initialise LXZ compressing backend cut trailing new-line, so the error string will look like zram: Cannot initialise LXZ compressing backend we also now can replace sysfs_streq() in zcomp_available_show() with strcmp(). Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@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>
* zram: cosmetic zram_bvec_write() cleanupSergey Senozhatsky2015-06-251-5/+3
| | | | | | | | | | | | `bool locked' local variable tells us if we should perform zcomp_strm_release() or not (jumped to `out' label before zcomp_strm_find() occurred), which is equivalent to `zstrm' being or not being NULL. remove `locked' and check `zstrm' instead. Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> 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>
* zram: add dynamic device add/remove functionalitySergey Senozhatsky2015-06-253-6/+141
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We currently don't support on-demand device creation. The one and only way to have N zram devices is to specify num_devices module parameter (default value: 1). IOW if, for some reason, at some point, user wants to have N + 1 devies he/she must umount all the existing devices, unload the module, load the module passing num_devices equals to N + 1. And do this again, if needed. This patch introduces zram control sysfs class, which has two sysfs attrs: - hot_add -- add a new zram device - hot_remove -- remove a specific (device_id) zram device hot_add sysfs attr is read-only and has only automatic device id assignment mode (as requested by Minchan Kim). read operation performed on this attr creates a new zram device and returns back its device_id or error status. Usage example: # add a new specific zram device cat /sys/class/zram-control/hot_add 2 # remove a specific zram device echo 4 > /sys/class/zram-control/hot_remove Returning zram_add() error code back to user (-ENOMEM in this case) cat /sys/class/zram-control/hot_add cat: /sys/class/zram-control/hot_add: Cannot allocate memory NOTE, there might be users who already depend on the fact that at least zram0 device gets always created by zram_init(). Preserve this behavior. [minchan@kernel.org: use zram->claim to avoid lockdep splat] Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.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>
* zram: close race by open overridingSergey Senozhatsky2015-06-252-19/+38
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | [ Original patch from Minchan Kim <minchan@kernel.org> ] Commit ba6b17d68c8e ("zram: fix umount-reset_store-mount race condition") introduced bdev->bd_mutex to protect a race between mount and reset. At that time, we don't have dynamic zram-add/remove feature so it was okay. However, as we introduce dynamic device feature, bd_mutex became trouble. CPU 0 echo 1 > /sys/block/zram<id>/reset -> kernfs->s_active(A) -> zram:reset_store->bd_mutex(B) CPU 1 echo <id> > /sys/class/zram/zram-remove ->zram:zram_remove: bd_mutex(B) -> sysfs_remove_group -> kernfs->s_active(A) IOW, AB -> BA deadlock The reason we are holding bd_mutex for zram_remove is to prevent any incoming open /dev/zram[0-9]. Otherwise, we could remove zram others already have opened. But it causes above deadlock problem. To fix the problem, this patch overrides block_device.open and it returns -EBUSY if zram asserts he claims zram to reset so any incoming open will be failed so we don't need to hold bd_mutex for zram_remove ayn more. This patch is to prepare for zram-add/remove feature. [sergey.senozhatsky@gmail.com: simplify reset_store()] Signed-off-by: Minchan Kim <minchan@kernel.org> Acked-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* zram: return zram device_id from zram_add()Sergey Senozhatsky2015-06-251-9/+14
| | | | | | | | | | | This patch prepares zram to enable on-demand device creation. zram_add() performs automatic device_id assignment and returns new device id (>= 0) or error code (< 0). Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> 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>
* zram: trivial: correct flag operations commentSergey Senozhatsky2015-06-251-1/+1
| | | | | | | | | | We don't have meta->tb_lock anymore and use meta table entry bit_spin_lock instead. update corresponding comment. Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> 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>
* zram: report every added and removed deviceSergey Senozhatsky2015-06-251-2/+3
| | | | | | | | | | | | | | | | | | | | | With dynamic device creation/removal (which will be introduced later in the series) printing num_devices in zram_init() will not make a lot of sense, as well as printing the number of destroyed devices in destroy_devices(). Print per-device action (added/removed) in zram_add() and zram_remove() instead. Example: [ 3645.259652] zram: Added device: zram5 [ 3646.152074] zram: Added device: zram6 [ 3650.585012] zram: Removed device: zram5 [ 3655.845584] zram: Added device: zram8 [ 3660.975223] zram: Removed device: zram6 Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> 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>
* zram: remove max_num_devices limitationSergey Senozhatsky2015-06-253-14/+4
| | | | | | | | | | | Limiting the number of zram devices to 32 (default max_num_devices value) is confusing, let's drop it. A user with 2TB or 4TB of RAM, for example, can request as many devices as he can handle. Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> 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>
* zram: reorganize code layoutSergey Senozhatsky2015-06-251-363/+362
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch looks big, but basically it just moves code blocks. No functional changes. Our current code layout looks like a sandwitch. For example, a) between read/write handlers, we have update_used_max() helper function: static int zram_decompress_page static int zram_bvec_read static inline void update_used_max static int zram_bvec_write static int zram_bvec_rw b) RW request handlers __zram_make_request/zram_bio_discard are divided by sysfs attr reset_store() function and corresponding zram_reset_device() handler: static void zram_bio_discard static void zram_reset_device static ssize_t disksize_store static ssize_t reset_store static void __zram_make_request c) we first a bunch of sysfs read/store functions. then a number of one-liners, then helper functions, RW functions, sysfs functions, helper functions again, and so on. Reorganize layout to be more logically grouped (a brief description, `cat zram_drv.c | grep static` gives a bigger picture): -- one-liners: zram_test_flag/etc. -- helpers: is_partial_io/update_position/etc -- sysfs attr show/store functions + ZRAM_ATTR_RO() generated stats show() functions exception: reset and disksize store functions are required to be after meta() functions. because we do device create/destroy actions in these sysfs handlers. -- "mm" functions: meta get/put, meta alloc/free, page free static inline bool zram_meta_get static inline void zram_meta_put static void zram_meta_free static struct zram_meta *zram_meta_alloc static void zram_free_page -- a block of I/O functions static int zram_decompress_page static int zram_bvec_read static int zram_bvec_write static void zram_bio_discard static int zram_bvec_rw static void __zram_make_request static void zram_make_request static void zram_slot_free_notify static int zram_rw_page -- device contol: add/remove/init/reset functions (+zram-control class will sit here) static int zram_reset_device static ssize_t reset_store static ssize_t disksize_store static int zram_add static void zram_remove static int __init zram_init static void __exit zram_exit Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> 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>
* zram: use idr instead of `zram_devices' arraySergey Senozhatsky2015-06-251-37/+49
| | | | | | | | | | | | | | | | | | This patch makes some preparations for on-demand device add/remove functionality. Remove `zram_devices' array and switch to id-to-pointer translation (idr). idr doesn't bloat zram struct with additional members, f.e. list_head, yet still provides ability to match the device_id with the device pointer. No user-space visible changes. [Julia.Lawall@lip6.fr: return -ENOMEM when `queue' alloc fails] Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Reported-by: Julia Lawall <Julia.Lawall@lip6.fr> 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>
* zram: cosmetic ZRAM_ATTR_RO code formatting tweakSergey Senozhatsky2015-06-251-1/+1
| | | | | | | | | Fix a misplaced backslash. Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> 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>
* zram: add `compact` sysfs entry to documentationSergey Senozhatsky2015-06-251-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We currently don't support zram on-demand device creation. The only way to have N zram devices is to specify num_devices module parameter (default value 1). That means that if, for some reason, at some point, user wants to have N + 1 devies he/she must umount all the existing devices, unload the module, load the module passing num_devices equals to N + 1. This patchset introduces zram-control sysfs class, which has two sysfs attrs: - hot_add -- add a new zram device - hot_remove -- remove a specific (device_id) zram device Usage example: # add a new specific zram device cat /sys/class/zram-control/hot_add 1 # remove a specific zram device echo 4 > /sys/class/zram-control/hot_remove This patch (of 10): Briefly describe missing `compact` sysfs entry. Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> 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>
* zsmalloc: remove obsolete ZSMALLOC_DEBUGMarcin Jabrzyk2015-06-251-4/+0
| | | | | | | | | | | The DEBUG define in zsmalloc is useless, there is no usage of it at all. Signed-off-by: Marcin Jabrzyk <m.jabrzyk@samsung.com> Acked-by: Sergey Senozhatsky <sergey.senozhatsky.work@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>
* zram: remove obsolete ZRAM_DEBUG optionMarcin Jabrzyk2015-06-252-13/+1
| | | | | | | | | | | This config option doesn't provide any usage for zram. Signed-off-by: Marcin Jabrzyk <m.jabrzyk@samsung.com> Acked-by: Sergey Senozhatsky <sergey.senozhatsky.work@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>
* s390/mm: change HPAGE_SHIFT type to intDominik Dingel2015-06-252-2/+2
| | | | | | | | | | | | | | With making HPAGE_SHIFT an unsigned integer we also accidentally changed pageblock_order. In order to avoid compiler warnings we make HPAGE_SHFIT an int again. Signed-off-by: Dominik Dingel <dingel@linux.vnet.ibm.com> Suggested-by: Andrew Morton <akpm@linux-foundation.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* s390/mm: forward check for huge pmds to pmd_large()Dominik Dingel2015-06-251-4/+1
| | | | | | | | | | | We already do the check in pmd_large, so we can just forward the call. Signed-off-by: Dominik Dingel <dingel@linux.vnet.ibm.com> Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* s390/hugetlb: remove dead code for sw emulated huge pagesDominik Dingel2015-06-252-60/+3
| | | | | | | | | | | | | We now support only hugepages on hardware with EDAT1 support. So we remove the prepare/release_hugepage hooks and simplify set_huge_pte_at and huge_ptep_get. Signed-off-by: Dominik Dingel <dingel@linux.vnet.ibm.com> Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm/hugetlb: remove arch_prepare/release_hugepage from arch headersDominik Dingel2015-06-2510-90/+0
| | | | | | | | | | | | | Nobody used these hooks so they were removed from common code, and can now be removed from the architectures. Signed-off-by: Dominik Dingel <dingel@linux.vnet.ibm.com> Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Acked-by: Ralf Baechle <ralf@linux-mips.org> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm/hugetlb: remove unused arch hook prepare/release_hugepageDominik Dingel2015-06-251-10/+0
| | | | | | | | | | | | With s390 dropping support for emulated hugepages, the last user of arch_prepare_hugepage and arch_release_hugepage is gone. Signed-off-by: Dominik Dingel <dingel@linux.vnet.ibm.com> Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* s390/mm: make hugepages_supported a boot time decisionDominik Dingel2015-06-253-4/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | There is a potential bug with KVM and hugetlbfs if the hardware does not support hugepages (EDAT1). We fix this by making EDAT1 a hard requirement for hugepages and therefore removing and simplifying code. As s390, with the sw-emulated hugepages, was the only user of arch_prepare/release_hugepage I also removed theses calls from common and other architecture code. This patch (of 5): By dropping support for hugepages on machines which do not have the hardware feature EDAT1, we fix a potential s390 KVM bug. The bug would happen if a guest is backed by hugetlbfs (not supported currently), but does not get pagetables with PGSTE. This would lead to random memory overwrites. Signed-off-by: Dominik Dingel <dingel@linux.vnet.ibm.com> Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge branch 'akpm' (patches from Andrew)Linus Torvalds2015-06-24151-1321/+2277
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Merge first patchbomb from Andrew Morton: - a few misc things - ocfs2 udpates - kernel/watchdog.c feature work (took ages to get right) - most of MM. A few tricky bits are held up and probably won't make 4.2. * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (91 commits) mm: kmemleak_alloc_percpu() should follow the gfp from per_alloc() mm, thp: respect MPOL_PREFERRED policy with non-local node tmpfs: truncate prealloc blocks past i_size mm/memory hotplug: print the last vmemmap region at the end of hot add memory mm/mmap.c: optimization of do_mmap_pgoff function mm: kmemleak: optimise kmemleak_lock acquiring during kmemleak_scan mm: kmemleak: avoid deadlock on the kmemleak object insertion error path mm: kmemleak: do not acquire scan_mutex in kmemleak_do_cleanup() mm: kmemleak: fix delete_object_*() race when called on the same memory block mm: kmemleak: allow safe memory scanning during kmemleak disabling memcg: convert mem_cgroup->under_oom from atomic_t to int memcg: remove unused mem_cgroup->oom_wakeups frontswap: allow multiple backends x86, mirror: x86 enabling - find mirrored memory ranges mm/memblock: allocate boot time data structures from mirrored memory mm/memblock: add extra "flags" to memblock to allow selection of memory based on attribute mm: do not ignore mapping_gfp_mask in page cache allocation paths mm/cma.c: fix typos in comments mm/oom_kill.c: print points as unsigned int mm/hugetlb: handle races in alloc_huge_page and hugetlb_reserve_pages ...
| * mm: kmemleak_alloc_percpu() should follow the gfp from per_alloc()Larry Finger2015-06-243-7/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Beginning at commit d52d3997f843 ("ipv6: Create percpu rt6_info"), the following INFO splat is logged: =============================== [ INFO: suspicious RCU usage. ] 4.1.0-rc7-next-20150612 #1 Not tainted ------------------------------- kernel/sched/core.c:7318 Illegal context switch in RCU-bh read-side critical section! other info that might help us debug this: rcu_scheduler_active = 1, debug_locks = 0 3 locks held by systemd/1: #0: (rtnl_mutex){+.+.+.}, at: [<ffffffff815f0c8f>] rtnetlink_rcv+0x1f/0x40 #1: (rcu_read_lock_bh){......}, at: [<ffffffff816a34e2>] ipv6_add_addr+0x62/0x540 #2: (addrconf_hash_lock){+...+.}, at: [<ffffffff816a3604>] ipv6_add_addr+0x184/0x540 stack backtrace: CPU: 0 PID: 1 Comm: systemd Not tainted 4.1.0-rc7-next-20150612 #1 Hardware name: TOSHIBA TECRA A50-A/TECRA A50-A, BIOS Version 4.20 04/17/2014 Call Trace: dump_stack+0x4c/0x6e lockdep_rcu_suspicious+0xe7/0x120 ___might_sleep+0x1d5/0x1f0 __might_sleep+0x4d/0x90 kmem_cache_alloc+0x47/0x250 create_object+0x39/0x2e0 kmemleak_alloc_percpu+0x61/0xe0 pcpu_alloc+0x370/0x630 Additional backtrace lines are truncated. In addition, the above splat is followed by several "BUG: sleeping function called from invalid context at mm/slub.c:1268" outputs. As suggested by Martin KaFai Lau, these are the clue to the fix. Routine kmemleak_alloc_percpu() always uses GFP_KERNEL for its allocations, whereas it should follow the gfp from its callers. Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Reviewed-by: Kamalesh Babulal <kamalesh@linux.vnet.ibm.com> Acked-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net> Cc: Martin KaFai Lau <kafai@fb.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Tejun Heo <tj@kernel.org> Cc: Christoph Lameter <cl@linux-foundation.org> Cc: <stable@vger.kernel.org> [3.18+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * mm, thp: respect MPOL_PREFERRED policy with non-local nodeVlastimil Babka2015-06-241-16/+22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Since commit 077fcf116c8c ("mm/thp: allocate transparent hugepages on local node"), we handle THP allocations on page fault in a special way - for non-interleave memory policies, the allocation is only attempted on the node local to the current CPU, if the policy's nodemask allows the node. This is motivated by the assumption that THP benefits cannot offset the cost of remote accesses, so it's better to fallback to base pages on the local node (which might still be available, while huge pages are not due to fragmentation) than to allocate huge pages on a remote node. The nodemask check prevents us from violating e.g. MPOL_BIND policies where the local node is not among the allowed nodes. However, the current implementation can still give surprising results for the MPOL_PREFERRED policy when the preferred node is different than the current CPU's local node. In such case we should honor the preferred node and not use the local node, which is what this patch does. If hugepage allocation on the preferred node fails, we fall back to base pages and don't try other nodes, with the same motivation as is done for the local node hugepage allocations. The patch also moves the MPOL_INTERLEAVE check around to simplify the hugepage specific test. The difference can be demonstrated using in-tree transhuge-stress test on the following 2-node machine where half memory on one node was occupied to show the difference. > numactl --hardware available: 2 nodes (0-1) node 0 cpus: 0 1 2 3 4 5 6 7 8 9 10 11 24 25 26 27 28 29 30 31 32 33 34 35 node 0 size: 7878 MB node 0 free: 3623 MB node 1 cpus: 12 13 14 15 16 17 18 19 20 21 22 23 36 37 38 39 40 41 42 43 44 45 46 47 node 1 size: 8045 MB node 1 free: 7818 MB node distances: node 0 1 0: 10 21 1: 21 10 Before the patch: > numactl -p0 -C0 ./transhuge-stress transhuge-stress: 2.197 s/loop, 0.276 ms/page, 7249.168 MiB/s 7962 succeed, 0 failed, 1786 different pages > numactl -p0 -C12 ./transhuge-stress transhuge-stress: 2.962 s/loop, 0.372 ms/page, 5376.172 MiB/s 7962 succeed, 0 failed, 3873 different pages Number of successful THP allocations corresponds to free memory on node 0 in the first case and node 1 in the second case, i.e. -p parameter is ignored and cpu binding "wins". After the patch: > numactl -p0 -C0 ./transhuge-stress transhuge-stress: 2.183 s/loop, 0.274 ms/page, 7295.516 MiB/s 7962 succeed, 0 failed, 1760 different pages > numactl -p0 -C12 ./transhuge-stress transhuge-stress: 2.878 s/loop, 0.361 ms/page, 5533.638 MiB/s 7962 succeed, 0 failed, 1750 different pages > numactl -p1 -C0 ./transhuge-stress transhuge-stress: 4.628 s/loop, 0.581 ms/page, 3440.893 MiB/s 7962 succeed, 0 failed, 3918 different pages The -p parameter is respected regardless of cpu binding. > numactl -C0 ./transhuge-stress transhuge-stress: 2.202 s/loop, 0.277 ms/page, 7230.003 MiB/s 7962 succeed, 0 failed, 1750 different pages > numactl -C12 ./transhuge-stress transhuge-stress: 3.020 s/loop, 0.379 ms/page, 5273.324 MiB/s 7962 succeed, 0 failed, 3916 different pages Without -p parameter, hugepage restriction to CPU-local node works as before. Fixes: 077fcf116c8c ("mm/thp: allocate transparent hugepages on local node") Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Acked-by: David Rientjes <rientjes@google.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Michal Hocko <mhocko@suse.cz> Cc: <stable@vger.kernel.org> [4.0+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * tmpfs: truncate prealloc blocks past i_sizeJosef Bacik2015-06-241-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | One of the rocksdb people noticed that when you do something like this fallocate(fd, FALLOC_FL_KEEP_SIZE, 0, 10M) pwrite(fd, buf, 5M, 0) ftruncate(5M) on tmpfs, the file would still take up 10M: which led to super fun issues because we were getting ENOSPC before we thought we should be getting ENOSPC. This patch fixes the problem, and mirrors what all the other fs'es do (and was agreed to be the correct behaviour at LSF). I tested it locally to make sure it worked properly with the following xfs_io -f -c "falloc -k 0 10M" -c "pwrite 0 5M" -c "truncate 5M" file Without the patch we have "Blocks: 20480", with the patch we have the correct value of "Blocks: 10240". Signed-off-by: Josef Bacik <jbacik@fb.com> Signed-off-by: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * mm/memory hotplug: print the last vmemmap region at the end of hot add memoryZhu Guihua2015-06-241-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When hot add two nodes continuously, we found the vmemmap region info is a bit messed. The last region of node 2 is printed when node 3 hot added, like the following: Initmem setup node 2 [mem 0x0000000000000000-0xffffffffffffffff] On node 2 totalpages: 0 Built 2 zonelists in Node order, mobility grouping on. Total pages: 16090539 Policy zone: Normal init_memory_mapping: [mem 0x40000000000-0x407ffffffff] [mem 0x40000000000-0x407ffffffff] page 1G [ffffea1000000000-ffffea10001fffff] PMD -> [ffff8a077d800000-ffff8a077d9fffff] on node 2 [ffffea1000200000-ffffea10003fffff] PMD -> [ffff8a077de00000-ffff8a077dffffff] on node 2 ... [ffffea101f600000-ffffea101f9fffff] PMD -> [ffff8a074ac00000-ffff8a074affffff] on node 2 [ffffea101fa00000-ffffea101fdfffff] PMD -> [ffff8a074a800000-ffff8a074abfffff] on node 2 Initmem setup node 3 [mem 0x0000000000000000-0xffffffffffffffff] On node 3 totalpages: 0 Built 3 zonelists in Node order, mobility grouping on. Total pages: 16090539 Policy zone: Normal init_memory_mapping: [mem 0x60000000000-0x607ffffffff] [mem 0x60000000000-0x607ffffffff] page 1G [ffffea101fe00000-ffffea101fffffff] PMD -> [ffff8a074a400000-ffff8a074a5fffff] on node 2 <=== node 2 ??? [ffffea1800000000-ffffea18001fffff] PMD -> [ffff8a074a600000-ffff8a074a7fffff] on node 3 [ffffea1800200000-ffffea18005fffff] PMD -> [ffff8a074a000000-ffff8a074a3fffff] on node 3 [ffffea1800600000-ffffea18009fffff] PMD -> [ffff8a0749c00000-ffff8a0749ffffff] on node 3 ... The cause is the last region was missed at the and of hot add memory, and p_start, p_end, node_start were not reset, so when hot add memory to a new node, it will consider they are not contiguous blocks and print the previous one. So we print the last vmemmap region at the end of hot add memory to avoid the confusion. Signed-off-by: Zhu Guihua <zhugh.fnst@cn.fujitsu.com> 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/mmap.c: optimization of do_mmap_pgoff functionPiotr Kwapulinski2015-06-241-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | The simple check for zero length memory mapping may be performed earlier. So that in case of zero length memory mapping some unnecessary code is not executed at all. It does not make the code less readable and saves some CPU cycles. Signed-off-by: Piotr Kwapulinski <kwapulinski.piotr@gmail.com> Acked-by: Michal Hocko <mhocko@suse.cz> Acked-by: 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: kmemleak: optimise kmemleak_lock acquiring during kmemleak_scanCatalin Marinas2015-06-241-34/+56
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The kmemleak memory scanning uses finer grained object->lock spinlocks primarily to avoid races with the memory block freeing. However, the pointer lookup in the rb tree requires the kmemleak_lock to be held. This is currently done in the find_and_get_object() function for each pointer-like location read during scanning. While this allows a low latency on kmemleak_*() callbacks on other CPUs, the memory scanning is slower. This patch moves the kmemleak_lock outside the scan_block() loop, acquiring/releasing it only once per scanned memory block. The allow_resched logic is moved outside scan_block() and a new scan_large_block() function is implemented which splits large blocks in MAX_SCAN_SIZE chunks with cond_resched() calls in-between. A redundant (object->flags & OBJECT_NO_SCAN) check is also removed from scan_object(). With this patch, the kmemleak scanning performance is significantly improved: at least 50% with lock debugging disabled and over an order of magnitude with lock proving enabled (on an arm64 system). Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * mm: kmemleak: avoid deadlock on the kmemleak object insertion error pathCatalin Marinas2015-06-241-4/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | While very unlikely (usually kmemleak or sl*b bug), the create_object() function in mm/kmemleak.c may fail to insert a newly allocated object into the rb tree. When this happens, kmemleak disables itself and prints additional information about the object already found in the rb tree. Such printing is done with the parent->lock acquired, however the kmemleak_lock is already held. This is a potential race with the scanning thread which acquires object->lock and kmemleak_lock in a This patch removes the locking around the 'parent' object information printing. Such object cannot be freed or removed from object_tree_root and object_list since kmemleak_lock is already held. There is a very small risk that some of the object data is being modified on another CPU but the only downside is inconsistent information printing. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * mm: kmemleak: do not acquire scan_mutex in kmemleak_do_cleanup()Catalin Marinas2015-06-241-2/+0
| | | | | | | | | | | | | | | | | | | | | | The kmemleak_do_cleanup() work thread already waits for the kmemleak_scan thread to finish via kthread_stop(). Waiting in kthread_stop() while scan_mutex is held may lead to deadlock if kmemleak_scan_thread() also waits to acquire for scan_mutex. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * mm: kmemleak: fix delete_object_*() race when called on the same memory blockCatalin Marinas2015-06-241-13/+26
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Calling delete_object_*() on the same pointer is not a standard use case (unless there is a bug in the code calling kmemleak_free()). However, during kmemleak disabling (error or user triggered via /sys), there is a potential race between kmemleak_free() calls on a CPU and __kmemleak_do_cleanup() on a different CPU. The current delete_object_*() implementation first performs a look-up holding kmemleak_lock, increments the object->use_count and then re-acquires kmemleak_lock to remove the object from object_tree_root and object_list. This patch simplifies the delete_object_*() mechanism to both look up and remove an object from the object_tree_root and object_list atomically (guarded by kmemleak_lock). This allows safe concurrent calls to delete_object_*() on the same pointer without additional locking for synchronising the kmemleak_free_enabled flag. A side effect is a slight improvement in the delete_object_*() performance by avoiding acquiring kmemleak_lock twice and incrementing/decrementing object->use_count. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * mm: kmemleak: allow safe memory scanning during kmemleak disablingCatalin Marinas2015-06-241-3/+16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The kmemleak scanning thread can run for minutes. Callbacks like kmemleak_free() are allowed during this time, the race being taken care of by the object->lock spinlock. Such lock also prevents a memory block from being freed or unmapped while it is being scanned by blocking the kmemleak_free() -> ... -> __delete_object() function until the lock is released in scan_object(). When a kmemleak error occurs (e.g. it fails to allocate its metadata), kmemleak_enabled is set and __delete_object() is no longer called on freed objects. If kmemleak_scan is running at the same time, kmemleak_free() no longer waits for the object scanning to complete, allowing the corresponding memory block to be freed or unmapped (in the case of vfree()). This leads to kmemleak_scan potentially triggering a page fault. This patch separates the kmemleak_free() enabling/disabling from the overall kmemleak_enabled nob so that we can defer the disabling of the object freeing tracking until the scanning thread completed. The kmemleak_free_part() is deliberately ignored by this patch since this is only called during boot before the scanning thread started. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Reported-by: Vignesh Radhakrishnan <vigneshr@codeaurora.org> Tested-by: Vignesh Radhakrishnan <vigneshr@codeaurora.org> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * memcg: convert mem_cgroup->under_oom from atomic_t to intTejun Heo2015-06-241-8/+21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | memcg->under_oom tracks whether the memcg is under OOM conditions and is an atomic_t counter managed with mem_cgroup_[un]mark_under_oom(). While atomic_t appears to be simple synchronization-wise, when used as a synchronization construct like here, it's trickier and more error-prone due to weak memory ordering rules, especially around atomic_read(), and false sense of security. For example, both non-trivial read sites of memcg->under_oom are a bit problematic although not being actually broken. * mem_cgroup_oom_register_event() It isn't explicit what guarantees the memory ordering between event addition and memcg->under_oom check. This isn't broken only because memcg_oom_lock is used for both event list and memcg->oom_lock. * memcg_oom_recover() The lockless test doesn't have any explanation why this would be safe. mem_cgroup_[un]mark_under_oom() are very cold paths and there's no point in avoiding locking memcg_oom_lock there. This patch converts memcg->under_oom from atomic_t to int, puts their modifications under memcg_oom_lock and documents why the lockless test in memcg_oom_recover() is safe. Signed-off-by: Tejun Heo <tj@kernel.org> 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>
| * memcg: remove unused mem_cgroup->oom_wakeupsTejun Heo2015-06-241-9/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Since commit 4942642080ea ("mm: memcg: handle non-error OOM situations more gracefully"), nobody uses mem_cgroup->oom_wakeups. Remove it. While at it, also fold memcg_wakeup_oom() into memcg_oom_recover() which is its only user. This cleanup was suggested by Michal. Signed-off-by: Tejun Heo <tj@kernel.org> 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>
| * frontswap: allow multiple backendsDan Streetman2015-06-243-98/+139
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Change frontswap single pointer to a singly linked list of frontswap implementations. Update Xen tmem implementation as register no longer returns anything. Frontswap only keeps track of a single implementation; any implementation that registers second (or later) will replace the previously registered implementation, and gets a pointer to the previous implementation that the new implementation is expected to pass all frontswap functions to if it can't handle the function itself. However that method doesn't really make much sense, as passing that work on to every implementation adds unnecessary work to implementations; instead, frontswap should simply keep a list of all registered implementations and try each implementation for any function. Most importantly, neither of the two currently existing frontswap implementations in the kernel actually do anything with any previous frontswap implementation that they replace when registering. This allows frontswap to successfully manage multiple implementations by keeping a list of them all. Signed-off-by: Dan Streetman <ddstreet@ieee.org> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: David Vrabel <david.vrabel@citrix.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * x86, mirror: x86 enabling - find mirrored memory rangesTony Luck2015-06-243-0/+27
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | UEFI GetMemoryMap() uses a new attribute bit to mark mirrored memory address ranges. See UEFI 2.5 spec pages 157-158: http://www.uefi.org/sites/default/files/resources/UEFI%202_5.pdf On EFI enabled systems scan the memory map and tell memblock about any mirrored ranges. Signed-off-by: Tony Luck <tony.luck@intel.com> Cc: Xishi Qiu <qiuxishi@huawei.com> Cc: Hanjun Guo <guohanjun@huawei.com> Cc: Xiexiuqi <xiexiuqi@huawei.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Yinghai Lu <yinghai@kernel.org> Cc: Naoya Horiguchi <nao.horiguchi@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * mm/memblock: allocate boot time data structures from mirrored memoryTony Luck2015-06-243-12/+84
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Try to allocate all boot time kernel data structures from mirrored memory. If we run out of mirrored memory print warnings, but fall back to using non-mirrored memory to make sure that we still boot. By number of bytes, most of what we allocate at boot time is the page structures. 64 bytes per 4K page on x86_64 ... or about 1.5% of total system memory. For workloads where the bulk of memory is allocated to applications this may represent a useful improvement to system availability since 1.5% of total memory might be a third of the memory allocated to the kernel. Signed-off-by: Tony Luck <tony.luck@intel.com> Cc: Xishi Qiu <qiuxishi@huawei.com> Cc: Hanjun Guo <guohanjun@huawei.com> Cc: Xiexiuqi <xiexiuqi@huawei.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Yinghai Lu <yinghai@kernel.org> Cc: Naoya Horiguchi <nao.horiguchi@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * mm/memblock: add extra "flags" to memblock to allow selection of memory ↵Tony Luck2015-06-2410-47/+83
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | based on attribute Some high end Intel Xeon systems report uncorrectable memory errors as a recoverable machine check. Linux has included code for some time to process these and just signal the affected processes (or even recover completely if the error was in a read only page that can be replaced by reading from disk). But we have no recovery path for errors encountered during kernel code execution. Except for some very specific cases were are unlikely to ever be able to recover. Enter memory mirroring. Actually 3rd generation of memory mirroing. Gen1: All memory is mirrored Pro: No s/w enabling - h/w just gets good data from other side of the mirror Con: Halves effective memory capacity available to OS/applications Gen2: Partial memory mirror - just mirror memory begind some memory controllers Pro: Keep more of the capacity Con: Nightmare to enable. Have to choose between allocating from mirrored memory for safety vs. NUMA local memory for performance Gen3: Address range partial memory mirror - some mirror on each memory controller Pro: Can tune the amount of mirror and keep NUMA performance Con: I have to write memory management code to implement The current plan is just to use mirrored memory for kernel allocations. This has been broken into two phases: 1) This patch series - find the mirrored memory, use it for boot time allocations 2) Wade into mm/page_alloc.c and define a ZONE_MIRROR to pick up the unused mirrored memory from mm/memblock.c and only give it out to select kernel allocations (this is still being scoped because page_alloc.c is scary). This patch (of 3): Add extra "flags" to memblock to allow selection of memory based on attribute. No functional changes Signed-off-by: Tony Luck <tony.luck@intel.com> Cc: Xishi Qiu <qiuxishi@huawei.com> Cc: Hanjun Guo <guohanjun@huawei.com> Cc: Xiexiuqi <xiexiuqi@huawei.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Yinghai Lu <yinghai@kernel.org> Cc: Naoya Horiguchi <nao.horiguchi@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * mm: do not ignore mapping_gfp_mask in page cache allocation pathsMichal Hocko2015-06-243-5/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | page_cache_read, do_generic_file_read, __generic_file_splice_read and __ntfs_grab_cache_pages currently ignore mapping_gfp_mask when calling add_to_page_cache_lru which might cause recursion into fs down in the direct reclaim path if the mapping really relies on GFP_NOFS semantic. This doesn't seem to be the case now because page_cache_read (page fault path) doesn't seem to suffer from the reclaim recursion issues and do_generic_file_read and __generic_file_splice_read also shouldn't be called under fs locks which would deadlock in the reclaim path. Anyway it is better to obey mapping gfp mask and prevent from later breakage. [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Michal Hocko <mhocko@suse.cz> Cc: Dave Chinner <david@fromorbit.com> Cc: Neil Brown <neilb@suse.de> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Mel Gorman <mgorman@suse.de> Cc: Rik van Riel <riel@redhat.com> Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Cc: Anton Altaparmakov <anton@tuxera.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * mm/cma.c: fix typos in commentsShailendra Verma2015-06-241-2/+2
| | | | | | | | | | | | | | Signed-off-by: Shailendra Verma <shailendra.capricorn@gmail.com> Acked-by: Michal Nazarewicz <mina86@mina86.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * mm/oom_kill.c: print points as unsigned intWang Long2015-06-241-1/+1
| | | | | | | | | | | | | | | | | | | | In oom_kill_process(), the variable 'points' is unsigned int. Print it as such. Signed-off-by: Wang Long <long.wanglong@huawei.com> Acked-by: Michal Hocko <mhocko@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * mm/hugetlb: handle races in alloc_huge_page and hugetlb_reserve_pagesMike Kravetz2015-06-241-4/+35
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | alloc_huge_page and hugetlb_reserve_pages use region_chg to calculate the number of pages which will be added to the reserve map. Subpool and global reserve counts are adjusted based on the output of region_chg. Before the pages are actually added to the reserve map, these routines could race and add fewer pages than expected. If this happens, the subpool and global reserve counts are not correct. Compare the number of pages actually added (region_add) to those expected to added (region_chg). If fewer pages are actually added, this indicates a race and adjust counters accordingly. Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com> Reviewed-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Reviewed-by: Davidlohr Bueso <dave@stgolabs.net> Cc: David Rientjes <rientjes@google.com> Cc: Luiz Capitulino <lcapitulino@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * mm/hugetlb: compute/return the number of regions added by region_add()Mike Kravetz2015-06-241-24/+48
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Modify region_add() to keep track of regions(pages) added to the reserve map and return this value. The return value can be compared to the return value of region_chg() to determine if the map was modified between calls. Make vma_commit_reservation() also pass along the return value of region_add(). In the normal case, we want vma_commit_reservation to return the same value as the preceding call to vma_needs_reservation. Create a common __vma_reservation_common routine to help keep the special case return values in sync Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: David Rientjes <rientjes@google.com> Cc: Luiz Capitulino <lcapitulino@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * mm/hugetlb: document the reserve map/region tracking routinesMike Kravetz2015-06-241-2/+50
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | While working on hugetlbfs fallocate support, I noticed the following race in the existing code. It is unlikely that this race is hit very often in the current code. However, if more functionality to add and remove pages to hugetlbfs mappings (such as fallocate) is added the likelihood of hitting this race will increase. alloc_huge_page and hugetlb_reserve_pages use information from the reserve map to determine if there are enough available huge pages to complete the operation, as well as adjust global reserve and subpool usage counts. The order of operations is as follows: - call region_chg() to determine the expected change based on reserve map - determine if enough resources are available for this operation - adjust global counts based on the expected change - call region_add() to update the reserve map The issue is that reserve map could change between the call to region_chg and region_add. In this case, the counters which were adjusted based on the output of region_chg will not be correct. In order to hit this race today, there must be an existing shared hugetlb mmap created with the MAP_NORESERVE flag. A page fault to allocate a huge page via this mapping must occur at the same another task is mapping the same region without the MAP_NORESERVE flag. The patch set does not prevent the race from happening. Rather, it adds simple functionality to detect when the race has occurred. If a race is detected, then the incorrect counts are adjusted. Review comments pointed out the need for documentation of the existing region/reserve map routines. This patch set also adds documentation in this area. This patch (of 3): This is a documentation only patch and does not modify any code. Descriptions of the routines used for reserve map/region tracking are added. Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: David Rientjes <rientjes@google.com> Cc: Luiz Capitulino <lcapitulino@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * Documentation/vm/unevictable-lru.txt: clarify MAP_LOCKED behaviorMichal Hocko2015-06-241-1/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | There is a very subtle difference between mmap()+mlock() vs mmap(MAP_LOCKED) semantic. The former one fails if the population of the area fails while the later one doesn't. This basically means that mmap(MAPLOCKED) areas might see major fault after mmap syscall returns which is not the case for mlock. mmap man page has already been altered but Documentation/vm/unevictable-lru.txt deserves a clarification as well. Signed-off-by: Michal Hocko <mhocko@suse.cz> Reported-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: nommu: refactor debug and warning printsLeon Romanovsky2015-06-241-92/+20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | kenter/kleave/kdebug are wrapper macros to print functions flow and debug information. This set was written before pr_devel() was introduced, so it was controlled by "#if 0" construction. It is questionable if anyone is using them [1] now. This patch removes these macros, converts numerous printk(KERN_WARNING, ...) to use general pr_warn(...) and removes debug print line from validate_mmap_request() function. Signed-off-by: Leon Romanovsky <leon@leon.nu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * mm: clarify that the function operates on hugepage pteAneesh Kumar K.V2015-06-2413-61/+65
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We have confusing functions to clear pmd, pmd_clear_* and pmd_clear. Add _huge_ to pmdp_clear functions so that we are clear that they operate on hugepage pte. We don't bother about other functions like pmdp_set_wrprotect, pmdp_clear_flush_young, because they operate on PTE bits and hence indicate they are operating on hugepage ptes Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * powerpc/mm: use generic version of pmdp_clear_flush()Aneesh Kumar K.V2015-06-245-22/+27
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Also move the pmd_trans_huge check to generic code. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * mm/thp: split out pmd collapse flush into separate functionsAneesh Kumar K.V2015-06-244-36/+67
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Architectures like ppc64 [1] need to do special things while clearing pmd before a collapse. For them this operation is largely different from a normal hugepage pte clear. Hence add a separate function to clear pmd before collapse. After this patch pmdp_* functions operate only on hugepage pte, and not on regular pmd_t values pointing to page table. [1] ppc64 needs to invalidate all the normal page pte mappings we already have inserted in the hardware hash page table. But before doing that we need to make sure there are no parallel hash page table insert going on. So we need to do a kick_all_cpus_sync() before flushing the older hash table entries. By moving this to a separate function we capture these details and mention how it is different from a hugepage pte clear. This patch is a cleanup and only does code movement for clarity. There should not be any change in functionality. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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