summaryrefslogtreecommitdiff
path: root/drivers/block/zram
AgeCommit message (Collapse)AuthorFilesLines
2020-03-27block: simplify queue allocationChristoph Hellwig1-3/+1
Current make_request based drivers use either blk_alloc_queue_node or blk_alloc_queue to allocate a queue, and then set up the make_request_fn function pointer and a few parameters using the blk_queue_make_request helper. Simplify this by passing the make_request pointer to blk_alloc_queue, and while at it merge the _node variant into the main helper by always passing a node_id, and remove the superfluous gfp_mask parameter. A lower-level __blk_alloc_queue is kept for the blk-mq case. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-03-25block: move the part_stat* helpers from genhd.h to a new headerChristoph Hellwig1-0/+1
These macros are just used by a few files. Move them out of genhd.h, which is included everywhere into a new standalone header. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-01-31drivers/block/zram/zram_drv.c: fix error return codes not being returned in ↵Colin Ian King1-2/+1
writeback_store Currently when an error code -EIO or -ENOSPC in the for-loop of writeback_store the error code is being overwritten by a ret = len assignment at the end of the function and the error codes are being lost. Fix this by assigning ret = len at the start of the function and remove the assignment from the end, hence allowing ret to be preserved when error codes are assigned to it. Addresses Coverity ("Unused value") Link: http://lkml.kernel.org/r/20191128122958.178290-1-colin.king@canonical.com Fixes: a939888ec38b ("zram: support idle/huge page writeback") Signed-off-by: Colin Ian King <colin.king@canonical.com> Acked-by: Minchan Kim <minchan@kernel.org> Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: Jens Axboe <axboe@kernel.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-01-31zram: try to avoid worst-case scenario on same element pagesTaejoon Song1-2/+5
The worst-case scenario on finding same element pages is that almost all elements are same at the first glance but only last few elements are different. Since the same element tends to be grouped from the beginning of the pages, if we check the first element with the last element before looping through all elements, we might have some chances to quickly detect non-same element pages. 1. Test is done under LG webOS TV (64-bit arch) 2. Dump the swap-out pages (~819200 pages) 3. Analyze the pages with simple test script which counts the iteration number and measures the speed at off-line Under 64-bit arch, the worst iteration count is PAGE_SIZE / 8 bytes = 512. The speed is based on the time to consume page_same_filled() function only. The result, on average, is listed as below: Num of Iter Speed(MB/s) Looping-Forward (Orig) 38 99265 Looping-Backward 36 102725 Last-element-check (This Patch) 33 125072 The result shows that the average iteration count decreases by 13% and the speed increases by 25% with this patch. This patch does not increase the overall time complexity, though. I also ran simpler version which uses backward loop. Just looping backward also makes some improvement, but less than this patch. [taejoon.song@lge.com: fix off-by-one] Link: http://lkml.kernel.org/r/1578642001-11765-1-git-send-email-taejoon.song@lge.com Link: http://lkml.kernel.org/r/1575424418-16119-1-git-send-email-taejoon.song@lge.com Signed-off-by: Taejoon Song <taejoon.song@lge.com> Acked-by: Minchan Kim <minchan@kernel.org> Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com> Cc: Jens Axboe <axboe@kernel.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-10-19zram: fix race between backing_dev_show and backing_dev_storeChenwandun1-2/+3
CPU0: CPU1: backing_dev_show backing_dev_store ...... ...... file = zram->backing_dev; down_read(&zram->init_lock); down_read(&zram->init_init_lock) file_path(file, ...); zram->backing_dev = backing_dev; up_read(&zram->init_lock); up_read(&zram->init_lock); gets the value of zram->backing_dev too early in backing_dev_show, which resultin the value being NULL at the beginning, and not NULL later. backtrace: d_path+0xcc/0x174 file_path+0x10/0x18 backing_dev_show+0x40/0xb4 dev_attr_show+0x20/0x54 sysfs_kf_seq_show+0x9c/0x10c kernfs_seq_show+0x28/0x30 seq_read+0x184/0x488 kernfs_fop_read+0x5c/0x1a4 __vfs_read+0x44/0x128 vfs_read+0xa0/0x138 SyS_read+0x54/0xb4 Link: http://lkml.kernel.org/r/1571046839-16814-1-git-send-email-chenwandun@huawei.com Signed-off-by: Chenwandun <chenwandun@huawei.com> Acked-by: Minchan Kim <minchan@kernel.org> Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: <stable@vger.kernel.org> [4.14+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-07-15docs: blockdev: add it to the admin-guideMauro Carvalho Chehab1-3/+3
The blockdev book basically contains user-faced documentation. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
2019-07-15docs: blockdev: convert to ReSTMauro Carvalho Chehab1-3/+3
Rename the blockdev documentation files to ReST, add an index for them and adjust in order to produce a nice html output via the Sphinx build system. The drbd sub-directory contains some graphs and data flows. Add those too to the documentation. At its new index.rst, let's add a :orphan: while this is not linked to the main index.rst file, in order to avoid build warnings. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
2019-05-30treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152Thomas Gleixner2-10/+2
Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation either version 2 of the license or at your option any later version extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 3029 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Allison Randal <allison@lohutok.net> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-21treewide: Add SPDX license identifier - Makefile/KconfigThomas Gleixner1-0/+1
Add SPDX license identifiers to all Make/Kconfig files which: - Have no license information of any form These files fall under the project license, GPL v2 only. The resulting SPDX license identifier is: GPL-2.0-only Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-04-26zram: pass down the bvec we need to read into in the work structJérôme Glisse1-2/+3
When scheduling work item to read page we need to pass down the proper bvec struct which points to the page to read into. Before this patch it uses a randomly initialized bvec (only if PAGE_SIZE != 4096) which is wrong. Note that without this patch on arch/kernel where PAGE_SIZE != 4096 userspace could read random memory through a zram block device (thought userspace probably would have no control on the address being read). Link: http://lkml.kernel.org/r/20190408183219.26377-1-jglisse@redhat.com Signed-off-by: Jérôme Glisse <jglisse@redhat.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Acked-by: Minchan Kim <minchan@kernel.org> Cc: Nitin Gupta <ngupta@vflare.org> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-03-29drivers/block/zram/zram_drv.c: fix idle/writeback string compareMinchan Kim1-26/+6
Makoto report a below KASAN error: zram does out-of-bounds read. Because strscpy copies from source up to count bytes unconditionally. It could cause out-of-bounds read on next object in slab. To prevent it, use strlcpy which checks source's length automatically. BUG: KASAN: slab-out-of-bounds in strscpy+0x68/0x154 Read of size 8 at addr ffffffc0c3495a00 by task system_server/1314 .. Call trace: strscpy+0x68/0x154 idle_store+0xc4/0x34c dev_attr_store+0x50/0x6c sysfs_kf_write+0x98/0xb4 kernfs_fop_write+0x198/0x260 __vfs_write+0x10c/0x338 vfs_write+0x114/0x238 SyS_write+0xc8/0x168 __sys_trace_return+0x0/0x4 Allocated by task 1314: __kmalloc+0x280/0x318 kernfs_fop_write+0xac/0x260 __vfs_write+0x10c/0x338 vfs_write+0x114/0x238 SyS_write+0xc8/0x168 __sys_trace_return+0x0/0x4 Freed by task 2855: kfree+0x138/0x630 kernfs_put_open_node+0x10c/0x124 kernfs_fop_release+0xd8/0x114 __fput+0x130/0x2a4 ____fput+0x1c/0x28 task_work_run+0x16c/0x1c8 do_notify_resume+0x2bc/0x107c work_pending+0x8/0x10 The buggy address belongs to the object at ffffffc0c3495a00 which belongs to the cache kmalloc-128 of size 128 The buggy address is located 0 bytes inside of 128-byte region [ffffffc0c3495a00, ffffffc0c3495a80) The buggy address belongs to the page: page:ffffffbf030d2500 count:1 mapcount:0 mapping: (null) index:0x0 compound_mapcount: 0 flags: 0x4000000000010200(slab|head) page dumped because: kasan: bad access detected Memory state around the buggy address: ffffffc0c3495900: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffffffc0c3495980: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffffffc0c3495a00: 04 fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ^ ffffffc0c3495a80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffffffc0c3495b00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 Link: http://lkml.kernel.org/r/20190319231911.145968-1-minchan@kernel.org Cc: <stable@vger.kernel.org> [5.0] Signed-off-by: Minchan Kim <minchan@kernel.org> Reported-by: Makoto Wu <makotowu@google.com> Reviewed-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>
2019-03-15zram: default to lzo-rle instead of lzoDave Rodgman1-1/+1
lzo-rle gives higher performance and similar compression ratios to lzo. Link: http://lkml.kernel.org/r/20190205155944.16007-4-dave.rodgman@arm.com Signed-off-by: Dave Rodgman <dave.rodgman@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-03-08lib/lzo: separate lzo-rle from lzoDave Rodgman1-0/+1
To prevent any issues with persistent data, separate lzo-rle from lzo so that it is treated as a separate algorithm, and lzo is still available. Link: http://lkml.kernel.org/r/20190205155944.16007-3-dave.rodgman@arm.com Signed-off-by: Dave Rodgman <dave.rodgman@arm.com> Cc: David S. Miller <davem@davemloft.net> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Herbert Xu <herbert@gondor.apana.org.au> Cc: Markus F.X.J. Oberhumer <markus@oberhumer.com> Cc: Matt Sealey <matt.sealey@arm.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Nitin Gupta <nitingupta910@gmail.com> Cc: Richard Purdie <rpurdie@openedhand.com> Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com> Cc: Sonny Rao <sonnyrao@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-01-09zram: idle writeback fixes and cleanupMinchan Kim2-26/+69
This patch includes some fixes and cleanup for idle-page writeback. 1. writeback_limit interface Now writeback_limit interface is rather conusing. For example, once writeback limit budget is exausted, admin can see 0 from /sys/block/zramX/writeback_limit which is same semantic with disable writeback_limit at this moment. IOW, admin cannot tell that zero came from disable writeback limit or exausted writeback limit. To make the interface clear, let's sepatate enable of writeback limit to another knob - /sys/block/zram0/writeback_limit_enable * before: while true : # to re-enable writeback limit once previous one is used up echo 0 > /sys/block/zram0/writeback_limit echo $((200<<20)) > /sys/block/zram0/writeback_limit .. .. # used up the writeback limit budget * new # To enable writeback limit, from the beginning, admin should # enable it. echo $((200<<20)) > /sys/block/zram0/writeback_limit echo 1 > /sys/block/zram/0/writeback_limit_enable while true : echo $((200<<20)) > /sys/block/zram0/writeback_limit .. .. # used up the writeback limit budget It's much strightforward. 2. fix condition check idle/huge writeback mode check The mode in writeback_store is not bit opeartion any more so no need to use bit operations. Furthermore, current condition check is broken in that it does writeback every pages regardless of huge/idle. 3. clean up idle_store No need to use goto. [minchan@kernel.org: missed spin_lock_init] Link: http://lkml.kernel.org/r/20190103001601.GA255139@google.com Link: http://lkml.kernel.org/r/20181224033529.19450-1-minchan@kernel.org Signed-off-by: Minchan Kim <minchan@kernel.org> Suggested-by: John Dias <joaodias@google.com> Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com> Cc: John Dias <joaodias@google.com> Cc: Srinivas Paladugu <srnvs@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-12-28zram: writeback throttleMinchan Kim2-3/+51
If there are lots of write IO with flash device, it could have a wearout problem of storage. To overcome the problem, admin needs to design write limitation to guarantee flash health for entire product life. This patch creates a new knob "writeback_limit" for zram. writeback_limit's default value is 0 so that it doesn't limit any writeback. If admin want to measure writeback count in a certain period, he could know it via /sys/block/zram0/bd_stat's 3rd column. If admin want to limit writeback as per-day 400M, he could do it like below. MB_SHIFT=20 4K_SHIFT=12 echo $((400<<MB_SHIFT>>4K_SHIFT)) > \ /sys/block/zram0/writeback_limit. If admin want to allow further write again, he could do it like below echo 0 > /sys/block/zram0/writeback_limit If admin want to see remaining writeback budget, cat /sys/block/zram0/writeback_limit The writeback_limit count will reset whenever you reset zram (e.g., system reboot, echo 1 > /sys/block/zramX/reset) so keeping how many of writeback happened until you reset the zram to allocate extra writeback budget in next setting is user's job. [minchan@kernel.org: v4] Link: http://lkml.kernel.org/r/20181203024045.153534-8-minchan@kernel.org Link: http://lkml.kernel.org/r/20181127055429.251614-8-minchan@kernel.org Signed-off-by: Minchan Kim <minchan@kernel.org> Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: Joey Pabalinas <joeypabalinas@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-12-28zram: add bd_stat statisticsMinchan Kim2-0/+34
bd_stat represents things that happened in the backing device. Currently it supports bd_counts, bd_reads and bd_writes which are helpful to understand wearout of flash and memory saving. [minchan@kernel.org: v4] Link: http://lkml.kernel.org/r/20181203024045.153534-7-minchan@kernel.org Link: http://lkml.kernel.org/r/20181127055429.251614-7-minchan@kernel.org Signed-off-by: Minchan Kim <minchan@kernel.org> Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: Joey Pabalinas <joeypabalinas@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-12-28zram: support idle/huge page writebackMinchan Kim3-75/+178
Add a new feature "zram idle/huge page writeback". In the zram-swap use case, zram usually has many idle/huge swap pages. It's pointless to keep them in memory (ie, zram). To solve this problem, this feature introduces idle/huge page writeback to the backing device so the goal is to save more memory space on embedded systems. Normal sequence to use idle/huge page writeback feature is as follows, while (1) { # mark allocated zram slot to idle echo all > /sys/block/zram0/idle # leave system working for several hours # Unless there is no access for some blocks on zram, # they are still IDLE marked pages. echo "idle" > /sys/block/zram0/writeback or/and echo "huge" > /sys/block/zram0/writeback # write the IDLE or/and huge marked slot into backing device # and free the memory. } Per the discussion at https://lore.kernel.org/lkml/20181122065926.GG3441@jagdpanzerIV/T/#u, This patch removes direct incommpressibe page writeback feature (d2afd25114f4 ("zram: write incompressible pages to backing device")). Below concerns from Sergey: == &< == "IDLE writeback" is superior to "incompressible writeback". "incompressible writeback" is completely unpredictable and uncontrollable; it depens on data patterns and compression algorithms. While "IDLE writeback" is predictable. I even suspect, that, *ideally*, we can remove "incompressible writeback". "IDLE pages" is a super set which also includes "incompressible" pages. So, technically, we still can do "incompressible writeback" from "IDLE writeback" path; but a much more reasonable one, based on a page idling period. I understand that you want to keep "direct incompressible writeback" around. ZRAM is especially popular on devices which do suffer from flash wearout, so I can see "incompressible writeback" path becoming a dead code, long term. == &< == Below concerns from Minchan: == &< == My concern is if we enable CONFIG_ZRAM_WRITEBACK in this implementation, both hugepage/idlepage writeck will turn on. However someuser want to enable only idlepage writeback so we need to introduce turn on/off knob for hugepage or new CONFIG_ZRAM_IDLEPAGE_WRITEBACK for those usecase. I don't want to make it complicated *if possible*. Long term, I imagine we need to make VM aware of new swap hierarchy a little bit different with as-is. For example, first high priority swap can return -EIO or -ENOCOMP, swap try to fallback to next lower priority swap device. With that, hugepage writeback will work tranparently. So we could regard it as regression because incompressible pages doesn't go to backing storage automatically. Instead, user should do it via "echo huge" > /sys/block/zram/writeback" manually. == &< == Link: http://lkml.kernel.org/r/20181127055429.251614-6-minchan@kernel.org Signed-off-by: Minchan Kim <minchan@kernel.org> Reviewed-by: Joey Pabalinas <joeypabalinas@gmail.com> Reviewed-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>
2018-12-28zram: introduce ZRAM_IDLE flagMinchan Kim2-3/+55
To support idle page writeback with upcoming patches, this patch introduces a new ZRAM_IDLE flag. Userspace can mark zram slots as "idle" via "echo all > /sys/block/zramX/idle" which marks every allocated zram slot as ZRAM_IDLE. User could see it by /sys/kernel/debug/zram/zram0/block_state. 300 75.033841 ...i 301 63.806904 s..i 302 63.806919 ..hi Once there is IO for the slot, the mark will be disappeared. 300 75.033841 ... 301 63.806904 s..i 302 63.806919 ..hi Therefore, 300th block is idle zpage. With this feature, user can how many zram has idle pages which are waste of memory. Link: http://lkml.kernel.org/r/20181127055429.251614-5-minchan@kernel.org Signed-off-by: Minchan Kim <minchan@kernel.org> Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Reviewed-by: Joey Pabalinas <joeypabalinas@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-12-28zram: refactor flags and writeback stuffMinchan Kim2-69/+44
Rename some variables and restructure some code for better readability in writeback and zs_free_page. Link: http://lkml.kernel.org/r/20181127055429.251614-4-minchan@kernel.org Signed-off-by: Minchan Kim <minchan@kernel.org> Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Reviewed-by: Joey Pabalinas <joeypabalinas@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-12-28zram: fix double free backing deviceMinchan Kim1-1/+3
If blkdev_get fails, we shouldn't do blkdev_put. Otherwise, kernel emits below log. This patch fixes it. WARNING: CPU: 0 PID: 1893 at fs/block_dev.c:1828 blkdev_put+0x105/0x120 Modules linked in: CPU: 0 PID: 1893 Comm: swapoff Not tainted 4.19.0+ #453 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1 04/01/2014 RIP: 0010:blkdev_put+0x105/0x120 Call Trace: __x64_sys_swapoff+0x46d/0x490 do_syscall_64+0x5a/0x190 entry_SYSCALL_64_after_hwframe+0x49/0xbe irq event stamp: 4466 hardirqs last enabled at (4465): __free_pages_ok+0x1e3/0x490 hardirqs last disabled at (4466): trace_hardirqs_off_thunk+0x1a/0x1c softirqs last enabled at (3420): __do_softirq+0x333/0x446 softirqs last disabled at (3407): irq_exit+0xd1/0xe0 Link: http://lkml.kernel.org/r/20181127055429.251614-3-minchan@kernel.org Signed-off-by: Minchan Kim <minchan@kernel.org> Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Reviewed-by: Joey Pabalinas <joeypabalinas@gmail.com> Cc: <stable@vger.kernel.org> [4.14+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-12-28zram: fix lockdep warning of free block handlingMinchan Kim2-18/+22
Patch series "zram idle page writeback", v3. Inherently, swap device has many idle pages which are rare touched since it was allocated. It is never problem if we use storage device as swap. However, it's just waste for zram-swap. This patchset supports zram idle page writeback feature. * Admin can define what is idle page "no access since X time ago" * Admin can define when zram should writeback them * Admin can define when zram should stop writeback to prevent wearout Details are in each patch's description. This patch (of 7): ================================ WARNING: inconsistent lock state 4.19.0+ #390 Not tainted -------------------------------- inconsistent {SOFTIRQ-ON-W} -> {IN-SOFTIRQ-W} usage. zram_verify/2095 [HC0[0]:SC1[1]:HE1:SE0] takes: 00000000b1828693 (&(&zram->bitmap_lock)->rlock){+.?.}, at: put_entry_bdev+0x1e/0x50 {SOFTIRQ-ON-W} state was registered at: _raw_spin_lock+0x2c/0x40 zram_make_request+0x755/0xdc9 generic_make_request+0x373/0x6a0 submit_bio+0x6c/0x140 __swap_writepage+0x3a8/0x480 shrink_page_list+0x1102/0x1a60 shrink_inactive_list+0x21b/0x3f0 shrink_node_memcg.constprop.99+0x4f8/0x7e0 shrink_node+0x7d/0x2f0 do_try_to_free_pages+0xe0/0x300 try_to_free_pages+0x116/0x2b0 __alloc_pages_slowpath+0x3f4/0xf80 __alloc_pages_nodemask+0x2a2/0x2f0 __handle_mm_fault+0x42e/0xb50 handle_mm_fault+0x55/0xb0 __do_page_fault+0x235/0x4b0 page_fault+0x1e/0x30 irq event stamp: 228412 hardirqs last enabled at (228412): [<ffffffff98245846>] __slab_free+0x3e6/0x600 hardirqs last disabled at (228411): [<ffffffff98245625>] __slab_free+0x1c5/0x600 softirqs last enabled at (228396): [<ffffffff98e0031e>] __do_softirq+0x31e/0x427 softirqs last disabled at (228403): [<ffffffff98072051>] irq_exit+0xd1/0xe0 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&(&zram->bitmap_lock)->rlock); <Interrupt> lock(&(&zram->bitmap_lock)->rlock); *** DEADLOCK *** no locks held by zram_verify/2095. stack backtrace: CPU: 5 PID: 2095 Comm: zram_verify Not tainted 4.19.0+ #390 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1 04/01/2014 Call Trace: <IRQ> dump_stack+0x67/0x9b print_usage_bug+0x1bd/0x1d3 mark_lock+0x4aa/0x540 __lock_acquire+0x51d/0x1300 lock_acquire+0x90/0x180 _raw_spin_lock+0x2c/0x40 put_entry_bdev+0x1e/0x50 zram_free_page+0xf6/0x110 zram_slot_free_notify+0x42/0xa0 end_swap_bio_read+0x5b/0x170 blk_update_request+0x8f/0x340 scsi_end_request+0x2c/0x1e0 scsi_io_completion+0x98/0x650 blk_done_softirq+0x9e/0xd0 __do_softirq+0xcc/0x427 irq_exit+0xd1/0xe0 do_IRQ+0x93/0x120 common_interrupt+0xf/0xf </IRQ> With writeback feature, zram_slot_free_notify could be called in softirq context by end_swap_bio_read. However, bitmap_lock is not aware of that so lockdep yell out: get_entry_bdev spin_lock(bitmap->lock); irq softirq end_swap_bio_read zram_slot_free_notify zram_slot_lock <-- deadlock prone zram_free_page put_entry_bdev spin_lock(bitmap->lock); <-- deadlock prone With akpm's suggestion (i.e. bitmap operation is already atomic), we could remove bitmap lock. It might fail to find a empty slot if serious contention happens. However, it's not severe problem because huge page writeback has already possiblity to fail if there is severe memory pressure. Worst case is just keeping the incompressible in memory, not storage. The other problem is zram_slot_lock in zram_slot_slot_free_notify. To make it safe is this patch introduces zram_slot_trylock where zram_slot_free_notify uses it. Although it's rare to be contented, this patch adds new debug stat "miss_free" to keep monitoring how often it happens. Link: http://lkml.kernel.org/r/20181127055429.251614-2-minchan@kernel.org Signed-off-by: Minchan Kim <minchan@kernel.org> Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Reviewed-by: Joey Pabalinas <joeypabalinas@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-10-10drivers/block: remove redundant 'default n' from Kconfig-sBartlomiej Zolnierkiewicz1-2/+0
'default n' is the default value for any bool or tristate Kconfig setting so there is no need to write it explicitly. Also since commit f467c5640c29 ("kconfig: only write '# CONFIG_FOO is not set' for visible symbols") the Kconfig behavior is the same regardless of 'default n' being present or not: ... One side effect of (and the main motivation for) this change is making the following two definitions behave exactly the same: config FOO bool config FOO bool default n With this change, neither of these will generate a '# CONFIG_FOO is not set' line (assuming FOO isn't selected/implied). That might make it clearer to people that a bare 'default n' is redundant. ... Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-09-28zram: register default groups with device_add_disk()Hannes Reinecke1-21/+7
Register default sysfs groups during device_add_disk() to avoid a race condition with udev during startup. Signed-off-by: Hannes Reinecke <hare@suse.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Nitin Gupta <ngupta@vflare.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Bart Van Assche <bart.vanassche@wdc.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-08-22drivers/block/zram/zram_drv.c: fix bug storing backing_devPeter Kalauskas1-1/+6
The call to strlcpy in backing_dev_store is incorrect. It should take the size of the destination buffer instead of the size of the source buffer. Additionally, ignore the newline character (\n) when reading the new file_name buffer. This makes it possible to set the backing_dev as follows: echo /dev/sdX > /sys/block/zram0/backing_dev The reason it worked before was the fact that strlcpy() copies 'len - 1' bytes, which is strlen(buf) - 1 in our case, so it accidentally didn't copy the trailing new line symbol. Which also means that "echo -n /dev/sdX" most likely was broken. Signed-off-by: Peter Kalauskas <peskal@google.com> Link: http://lkml.kernel.org/r/20180813061623.GC64836@rodete-desktop-imager.corp.google.com Acked-by: Minchan Kim <minchan@kernel.org> Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: <stable@vger.kernel.org> [4.14+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-14Merge tag 'for-4.19/block-20180812' of git://git.kernel.dk/linux-blockLinus Torvalds1-10/+9
Pull block updates from Jens Axboe: "First pull request for this merge window, there will also be a followup request with some stragglers. This pull request contains: - Fix for a thundering heard issue in the wbt block code (Anchal Agarwal) - A few NVMe pull requests: * Improved tracepoints (Keith) * Larger inline data support for RDMA (Steve Wise) * RDMA setup/teardown fixes (Sagi) * Effects log suppor for NVMe target (Chaitanya Kulkarni) * Buffered IO suppor for NVMe target (Chaitanya Kulkarni) * TP4004 (ANA) support (Christoph) * Various NVMe fixes - Block io-latency controller support. Much needed support for properly containing block devices. (Josef) - Series improving how we handle sense information on the stack (Kees) - Lightnvm fixes and updates/improvements (Mathias/Javier et al) - Zoned device support for null_blk (Matias) - AIX partition fixes (Mauricio Faria de Oliveira) - DIF checksum code made generic (Max Gurtovoy) - Add support for discard in iostats (Michael Callahan / Tejun) - Set of updates for BFQ (Paolo) - Removal of async write support for bsg (Christoph) - Bio page dirtying and clone fixups (Christoph) - Set of bcache fix/changes (via Coly) - Series improving blk-mq queue setup/teardown speed (Ming) - Series improving merging performance on blk-mq (Ming) - Lots of other fixes and cleanups from a slew of folks" * tag 'for-4.19/block-20180812' of git://git.kernel.dk/linux-block: (190 commits) blkcg: Make blkg_root_lookup() work for queues in bypass mode bcache: fix error setting writeback_rate through sysfs interface null_blk: add lock drop/acquire annotation Blk-throttle: reduce tail io latency when iops limit is enforced block: paride: pd: mark expected switch fall-throughs block: Ensure that a request queue is dissociated from the cgroup controller block: Introduce blk_exit_queue() blkcg: Introduce blkg_root_lookup() block: Remove two superfluous #include directives blk-mq: count the hctx as active before allocating tag block: bvec_nr_vecs() returns value for wrong slab bcache: trivial - remove tailing backslash in macro BTREE_FLAG bcache: make the pr_err statement used for ENOENT only in sysfs_attatch section bcache: set max writeback rate when I/O request is idle bcache: add code comments for bset.c bcache: fix mistaken comments in request.c bcache: fix mistaken code comments in bcache.h bcache: add a comment in super.c bcache: avoid unncessary cache prefetch bch_btree_node_get() bcache: display rate debug parameters to 0 when writeback is not running ...
2018-08-11zram: remove BD_CAP_SYNCHRONOUS_IO with writeback featureMinchan Kim1-1/+14
If zram supports writeback feature, it's no longer a BD_CAP_SYNCHRONOUS_IO device beause zram does asynchronous IO operations for incompressible pages. Do not pretend to be synchronous IO device. It makes the system very sluggish due to waiting for IO completion from upper layers. Furthermore, it causes a user-after-free problem because swap thinks the opearion is done when the IO functions returns so it can free the page (e.g., lock_page_or_retry and goto out_release in do_swap_page) but in fact, IO is asynchronous so the driver could access a just freed page afterward. This patch fixes the problem. BUG: Bad page state in process qemu-system-x86 pfn:3dfab21 page:ffffdfb137eac840 count:0 mapcount:0 mapping:0000000000000000 index:0x1 flags: 0x17fffc000000008(uptodate) raw: 017fffc000000008 dead000000000100 dead000000000200 0000000000000000 raw: 0000000000000001 0000000000000000 00000000ffffffff 0000000000000000 page dumped because: PAGE_FLAGS_CHECK_AT_PREP flag set bad because of flags: 0x8(uptodate) CPU: 4 PID: 1039 Comm: qemu-system-x86 Tainted: G B 4.18.0-rc5+ #1 Hardware name: Supermicro Super Server/X10SRL-F, BIOS 2.0b 05/02/2017 Call Trace: dump_stack+0x5c/0x7b bad_page+0xba/0x120 get_page_from_freelist+0x1016/0x1250 __alloc_pages_nodemask+0xfa/0x250 alloc_pages_vma+0x7c/0x1c0 do_swap_page+0x347/0x920 __handle_mm_fault+0x7b4/0x1110 handle_mm_fault+0xfc/0x1f0 __get_user_pages+0x12f/0x690 get_user_pages_unlocked+0x148/0x1f0 __gfn_to_pfn_memslot+0xff/0x3c0 [kvm] try_async_pf+0x87/0x230 [kvm] tdp_page_fault+0x132/0x290 [kvm] kvm_mmu_page_fault+0x74/0x570 [kvm] kvm_arch_vcpu_ioctl_run+0x9b3/0x1990 [kvm] kvm_vcpu_ioctl+0x388/0x5d0 [kvm] do_vfs_ioctl+0xa2/0x630 ksys_ioctl+0x70/0x80 __x64_sys_ioctl+0x16/0x20 do_syscall_64+0x55/0x100 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Link: https://lore.kernel.org/lkml/0516ae2d-b0fd-92c5-aa92-112ba7bd32fc@contabo.de/ Link: http://lkml.kernel.org/r/20180802051112.86174-1-minchan@kernel.org [minchan@kernel.org: fix changelog, add comment] Link: https://lore.kernel.org/lkml/0516ae2d-b0fd-92c5-aa92-112ba7bd32fc@contabo.de/ Link: http://lkml.kernel.org/r/20180802051112.86174-1-minchan@kernel.org Link: http://lkml.kernel.org/r/20180805233722.217347-1-minchan@kernel.org [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Minchan Kim <minchan@kernel.org> Reported-by: Tino Lehnig <tino.lehnig@contabo.de> Tested-by: Tino Lehnig <tino.lehnig@contabo.de> Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: <stable@vger.kernel.org> [4.15+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-07-18block: Add and use op_stat_group() for indexing disk_stat fields.Michael Callahan1-3/+2
Add and use a new op_stat_group() function for indexing partition stat fields rather than indexing them by rq_data_dir() or bio_data_dir(). This function works similarly to op_is_sync() in that it takes the request::cmd_flags or bio::bi_opf flags and determines which stats should et updated. In addition, the second parameter to generic_start_io_acct() and generic_end_io_acct() is now a REQ_OP rather than simply a read or write bit and it uses op_stat_group() on the parameter to determine the stat group. Note that the partition in_flight counts are not part of the per-cpu statistics and as such are not indexed via this function. It's now indexed by op_is_write(). tj: Refreshed on top of v4.17. Updated to pass around REQ_OP. Signed-off-by: Michael Callahan <michaelcallahan@fb.com> Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Joshua Morris <josh.h.morris@us.ibm.com> Cc: Philipp Reisner <philipp.reisner@linbit.com> Cc: Matias Bjorling <mb@lightnvm.io> Cc: Kent Overstreet <kent.overstreet@gmail.com> Cc: Alasdair Kergon <agk@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-07-18block: make bdev_ops->rw_page() take a REQ_OP instead of boolTejun Heo1-8/+8
c11f0c0b5bb9 ("block/mm: make bdev_ops->rw_page() take a bool for read/write") replaced @op with boolean @is_write, which limited the amount of information going into ->rw_page() and more importantly page_endio(), which removed the need to expose block internals to mm. Unfortunately, we want to track discards separately and @is_write isn't enough information. This patch updates bdev_ops->rw_page() to take REQ_OP instead but leaves page_endio() to take bool @is_write. This allows the block part of operations to have enough information while not leaking it to mm. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Mike Christie <mchristi@redhat.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-06-13treewide: Use array_size() in vzalloc()Kees Cook1-1/+1
The vzalloc() function has no 2-factor argument form, so multiplication factors need to be wrapped in array_size(). This patch replaces cases of: vzalloc(a * b) with: vzalloc(array_size(a, b)) as well as handling cases of: vzalloc(a * b * c) with: vzalloc(array3_size(a, b, c)) This does, however, attempt to ignore constant size factors like: vzalloc(4 * 1024) though any constants defined via macros get caught up in the conversion. Any factors with a sizeof() of "unsigned char", "char", and "u8" were dropped, since they're redundant. The Coccinelle script used for this was: // Fix redundant parens around sizeof(). @@ type TYPE; expression THING, E; @@ ( vzalloc( - (sizeof(TYPE)) * E + sizeof(TYPE) * E , ...) | vzalloc( - (sizeof(THING)) * E + sizeof(THING) * E , ...) ) // Drop single-byte sizes and redundant parens. @@ expression COUNT; typedef u8; typedef __u8; @@ ( vzalloc( - sizeof(u8) * (COUNT) + COUNT , ...) | vzalloc( - sizeof(__u8) * (COUNT) + COUNT , ...) | vzalloc( - sizeof(char) * (COUNT) + COUNT , ...) | vzalloc( - sizeof(unsigned char) * (COUNT) + COUNT , ...) | vzalloc( - sizeof(u8) * COUNT + COUNT , ...) | vzalloc( - sizeof(__u8) * COUNT + COUNT , ...) | vzalloc( - sizeof(char) * COUNT + COUNT , ...) | vzalloc( - sizeof(unsigned char) * COUNT + COUNT , ...) ) // 2-factor product with sizeof(type/expression) and identifier or constant. @@ type TYPE; expression THING; identifier COUNT_ID; constant COUNT_CONST; @@ ( vzalloc( - sizeof(TYPE) * (COUNT_ID) + array_size(COUNT_ID, sizeof(TYPE)) , ...) | vzalloc( - sizeof(TYPE) * COUNT_ID + array_size(COUNT_ID, sizeof(TYPE)) , ...) | vzalloc( - sizeof(TYPE) * (COUNT_CONST) + array_size(COUNT_CONST, sizeof(TYPE)) , ...) | vzalloc( - sizeof(TYPE) * COUNT_CONST + array_size(COUNT_CONST, sizeof(TYPE)) , ...) | vzalloc( - sizeof(THING) * (COUNT_ID) + array_size(COUNT_ID, sizeof(THING)) , ...) | vzalloc( - sizeof(THING) * COUNT_ID + array_size(COUNT_ID, sizeof(THING)) , ...) | vzalloc( - sizeof(THING) * (COUNT_CONST) + array_size(COUNT_CONST, sizeof(THING)) , ...) | vzalloc( - sizeof(THING) * COUNT_CONST + array_size(COUNT_CONST, sizeof(THING)) , ...) ) // 2-factor product, only identifiers. @@ identifier SIZE, COUNT; @@ vzalloc( - SIZE * COUNT + array_size(COUNT, SIZE) , ...) // 3-factor product with 1 sizeof(type) or sizeof(expression), with // redundant parens removed. @@ expression THING; identifier STRIDE, COUNT; type TYPE; @@ ( vzalloc( - sizeof(TYPE) * (COUNT) * (STRIDE) + array3_size(COUNT, STRIDE, sizeof(TYPE)) , ...) | vzalloc( - sizeof(TYPE) * (COUNT) * STRIDE + array3_size(COUNT, STRIDE, sizeof(TYPE)) , ...) | vzalloc( - sizeof(TYPE) * COUNT * (STRIDE) + array3_size(COUNT, STRIDE, sizeof(TYPE)) , ...) | vzalloc( - sizeof(TYPE) * COUNT * STRIDE + array3_size(COUNT, STRIDE, sizeof(TYPE)) , ...) | vzalloc( - sizeof(THING) * (COUNT) * (STRIDE) + array3_size(COUNT, STRIDE, sizeof(THING)) , ...) | vzalloc( - sizeof(THING) * (COUNT) * STRIDE + array3_size(COUNT, STRIDE, sizeof(THING)) , ...) | vzalloc( - sizeof(THING) * COUNT * (STRIDE) + array3_size(COUNT, STRIDE, sizeof(THING)) , ...) | vzalloc( - sizeof(THING) * COUNT * STRIDE + array3_size(COUNT, STRIDE, sizeof(THING)) , ...) ) // 3-factor product with 2 sizeof(variable), with redundant parens removed. @@ expression THING1, THING2; identifier COUNT; type TYPE1, TYPE2; @@ ( vzalloc( - sizeof(TYPE1) * sizeof(TYPE2) * COUNT + array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2)) , ...) | vzalloc( - sizeof(TYPE1) * sizeof(THING2) * (COUNT) + array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2)) , ...) | vzalloc( - sizeof(THING1) * sizeof(THING2) * COUNT + array3_size(COUNT, sizeof(THING1), sizeof(THING2)) , ...) | vzalloc( - sizeof(THING1) * sizeof(THING2) * (COUNT) + array3_size(COUNT, sizeof(THING1), sizeof(THING2)) , ...) | vzalloc( - sizeof(TYPE1) * sizeof(THING2) * COUNT + array3_size(COUNT, sizeof(TYPE1), sizeof(THING2)) , ...) | vzalloc( - sizeof(TYPE1) * sizeof(THING2) * (COUNT) + array3_size(COUNT, sizeof(TYPE1), sizeof(THING2)) , ...) ) // 3-factor product, only identifiers, with redundant parens removed. @@ identifier STRIDE, SIZE, COUNT; @@ ( vzalloc( - (COUNT) * STRIDE * SIZE + array3_size(COUNT, STRIDE, SIZE) , ...) | vzalloc( - COUNT * (STRIDE) * SIZE + array3_size(COUNT, STRIDE, SIZE) , ...) | vzalloc( - COUNT * STRIDE * (SIZE) + array3_size(COUNT, STRIDE, SIZE) , ...) | vzalloc( - (COUNT) * (STRIDE) * SIZE + array3_size(COUNT, STRIDE, SIZE) , ...) | vzalloc( - COUNT * (STRIDE) * (SIZE) + array3_size(COUNT, STRIDE, SIZE) , ...) | vzalloc( - (COUNT) * STRIDE * (SIZE) + array3_size(COUNT, STRIDE, SIZE) , ...) | vzalloc( - (COUNT) * (STRIDE) * (SIZE) + array3_size(COUNT, STRIDE, SIZE) , ...) | vzalloc( - COUNT * STRIDE * SIZE + array3_size(COUNT, STRIDE, SIZE) , ...) ) // Any remaining multi-factor products, first at least 3-factor products // when they're not all constants... @@ expression E1, E2, E3; constant C1, C2, C3; @@ ( vzalloc(C1 * C2 * C3, ...) | vzalloc( - E1 * E2 * E3 + array3_size(E1, E2, E3) , ...) ) // And then all remaining 2 factors products when they're not all constants. @@ expression E1, E2; constant C1, C2; @@ ( vzalloc(C1 * C2, ...) | vzalloc( - E1 * E2 + array_size(E1, E2) , ...) ) Signed-off-by: Kees Cook <keescook@chromium.org>
2018-06-08zram: introduce zram memory trackingMinchan Kim3-14/+139
zRam as swap is useful for small memory device. However, swap means those pages on zram are mostly cold pages due to VM's LRU algorithm. Especially, once init data for application are touched for launching, they tend to be not accessed any more and finally swapped out. zRAM can store such cold pages as compressed form but it's pointless to keep in memory. Better idea is app developers free them directly rather than remaining them on heap. This patch tell us last access time of each block of zram via "cat /sys/kernel/debug/zram/zram0/block_state". The output is as follows, 300 75.033841 .wh 301 63.806904 s.. 302 63.806919 ..h First column is zram's block index and 3rh one represents symbol (s: same page w: written page to backing store h: huge page) of the block state. Second column represents usec time unit of the block was last accessed. So above example means the 300th block is accessed at 75.033851 second and it was huge so it was written to the backing store. Admin can leverage this information to catch cold|incompressible pages of process with *pagemap* once part of heaps are swapped out. I used the feature a few years ago to find memory hoggers in userspace to notify them what memory they have wasted without touch for a long time. With it, they could reduce unnecessary memory space. However, at that time, I hacked up zram for the feature but now I need the feature again so I decided it would be better to upstream rather than keeping it alone. I hope I submit the userspace tool to use the feature soon. [akpm@linux-foundation.org: fix i386 printk warning] [minchan@kernel.org: use ktime_get_boottime() instead of sched_clock()] Link: http://lkml.kernel.org/r/20180420063525.GA253739@rodete-desktop-imager.corp.google.com [akpm@linux-foundation.org: documentation tweak] [akpm@linux-foundation.org: fix i386 printk warning] [minchan@kernel.org: fix compile warning] Link: http://lkml.kernel.org/r/20180508104849.GA8209@rodete-desktop-imager.corp.google.com [rdunlap@infradead.org: fix printk formats] Link: http://lkml.kernel.org/r/3652ccb1-96ef-0b0b-05d1-f661d7733dcc@infradead.org Link: http://lkml.kernel.org/r/20180416090946.63057-5-minchan@kernel.org Signed-off-by: Minchan Kim <minchan@kernel.org> Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-06-08zram: record accessed secondMinchan Kim2-0/+17
zRam as swap is useful for small memory device. However, swap means those pages on zram are mostly cold pages due to VM's LRU algorithm. Especially, once init data for application are touched for launching, they tend to be not accessed any more and finally swapped out. zRAM can store such cold pages as compressed form but it's pointless to keep in memory. Better idea is app developers free them directly rather than remaining them on heap. This patch records last access time of each block of zram so that With upcoming zram memory tracking, it could help userspace developers to reduce memory footprint. Link: http://lkml.kernel.org/r/20180416090946.63057-4-minchan@kernel.org Signed-off-by: Minchan Kim <minchan@kernel.org> Reviewed-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>
2018-06-08zram: mark incompressible page as ZRAM_HUGEMinchan Kim2-3/+16
Mark incompressible pages so that we could investigate who is the owner of the incompressible pages once the page is swapped out via using upcoming zram memory tracker feature. With it, we could prevent such pages to be swapped out by using mlock. Otherwise we might remove them. This patch exposes new stat for huge pages via mm_stat. Link: http://lkml.kernel.org/r/20180416090946.63057-3-minchan@kernel.org Signed-off-by: Minchan Kim <minchan@kernel.org> Reviewed-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>
2018-06-08zram: correct flag name of ZRAM_ACCESSMinchan Kim2-13/+13
Patch series "zram memory tracking", v5. zRam as swap is useful for small memory device. However, swap means those pages on zram are mostly cold pages due to VM's LRU algorithm. Especially, once init data for application are touched for launching, they tend to be not accessed any more and finally swapped out. zRAM can store such cold pages as compressed form but it's pointless to keep in memory. As well, it's pointless to store incompressible pages to zram so better idea is app developers manages them directly like free or mlock rather than remaining them on heap. This patch provides a debugfs /sys/kernel/debug/zram/zram0/block_state to represent each block's state so admin can investigate what memory is cold|incompressible|same page with using pagemap once the pages are swapped out. The output is as follows: 300 75.033841 .wh 301 63.806904 s.. 302 63.806919 ..h First column is zram's block index and 3rh one represents symbol (s: same page w: written page to backing store h: huge page) of the block state. Second column represents usec time unit of the block was last accessed. So above example means the 300th block is accessed at 75.033851 second and it was huge so it was written to the backing store. This patch (of 4): ZRAM_ACCESS is used for locking a slot of zram so correct the name. It is also not a common flag to indicate status of the block so move the declare position on top of the flag. Lastly, let's move the function to the top of source code to be able to use it easily without forward declaration. Link: http://lkml.kernel.org/r/20180416090946.63057-2-minchan@kernel.org Signed-off-by: Minchan Kim <minchan@kernel.org> Reviewed-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>
2018-04-07Merge branch 'akpm' (patches from Andrew)Linus Torvalds2-17/+8
Merge updates from Andrew Morton: - a few misc things - ocfs2 updates - the v9fs maintainers have been missing for a long time. I've taken over v9fs patch slinging. - most of MM * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (116 commits) mm,oom_reaper: check for MMF_OOM_SKIP before complaining mm/ksm: fix interaction with THP mm/memblock.c: cast constant ULLONG_MAX to phys_addr_t headers: untangle kmemleak.h from mm.h include/linux/mmdebug.h: make VM_WARN* non-rvals mm/page_isolation.c: make start_isolate_page_range() fail if already isolated mm: change return type to vm_fault_t mm, oom: remove 3% bonus for CAP_SYS_ADMIN processes mm, page_alloc: wakeup kcompactd even if kswapd cannot free more memory kernel/fork.c: detect early free of a live mm mm: make counting of list_lru_one::nr_items lockless mm/swap_state.c: make bool enable_vma_readahead and swap_vma_readahead() static block_invalidatepage(): only release page if the full page was invalidated mm: kernel-doc: add missing parameter descriptions mm/swap.c: remove @cold parameter description for release_pages() mm/nommu: remove description of alloc_vm_area zram: drop max_zpage_size and use zs_huge_class_size() zsmalloc: introduce zs_huge_class_size() mm: fix races between swapoff and flush dcache fs/direct-io.c: minor cleanups in do_blockdev_direct_IO ...
2018-04-06zram: drop max_zpage_size and use zs_huge_class_size()Sergey Senozhatsky2-17/+8
Remove ZRAM's enforced "huge object" value and use zsmalloc huge-class watermark instead, which makes more sense. TEST - I used a 1G zram device, LZO compression back-end, original data set size was 444MB. Looking at zsmalloc classes stats the test ended up to be pretty fair. BASE ZRAM/ZSMALLOC ===================== zram mm_stat 498978816 191482495 199831552 0 199831552 15634 0 zsmalloc classes class size almost_full almost_empty obj_allocated obj_used pages_used pages_per_zspage freeable ... 151 2448 0 0 1240 1240 744 3 0 168 2720 0 0 4200 4200 2800 2 0 190 3072 0 0 10100 10100 7575 3 0 202 3264 0 0 380 380 304 4 0 254 4096 0 0 10620 10620 10620 1 0 Total 7 46 106982 106187 48787 0 PATCHED ZRAM/ZSMALLOC ===================== zram mm_stat 498978816 182579184 194248704 0 194248704 15628 0 zsmalloc classes class size almost_full almost_empty obj_allocated obj_used pages_used pages_per_zspage freeable ... 151 2448 0 0 1240 1240 744 3 0 168 2720 0 0 4200 4200 2800 2 0 190 3072 0 0 10100 10100 7575 3 0 202 3264 0 0 7180 7180 5744 4 0 254 4096 0 0 3820 3820 3820 1 0 Total 8 45 106959 106193 47424 0 As we can see, we reduced the number of objects stored in class-4096, because a huge number of objects which we previously forcibly stored in class-4096 now stored in non-huge class-3264. This results in lower memory consumption: - zsmalloc now uses 47424 physical pages, which is less than 48787 pages zsmalloc used before. - objects that we store in class-3264 share zspages. That's why overall the number of pages that both class-4096 and class-3264 consumed went down from 10924 to 9564. [sergey.senozhatsky.work@gmail.com: add pool param to zs_huge_class_size()] Link: http://lkml.kernel.org/r/20180314081833.1096-3-sergey.senozhatsky@gmail.com Link: http://lkml.kernel.org/r/20180306070639.7389-3-sergey.senozhatsky@gmail.com Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Acked-by: Minchan Kim <minchan@kernel.org> Cc: Mike Rapoport <rppt@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-03-17block: Move SECTOR_SIZE and SECTOR_SHIFT definitions into <linux/blkdev.h>Bart Van Assche1-1/+0
It happens often while I'm preparing a patch for a block driver that I'm wondering: is a definition of SECTOR_SIZE and/or SECTOR_SHIFT available for this driver? Do I have to introduce definitions of these constants before I can use these constants? To avoid this confusion, move the existing definitions of SECTOR_SIZE and SECTOR_SHIFT into the <linux/blkdev.h> header file such that these become available for all block drivers. Make the SECTOR_SIZE definition in the uapi msdos_fs.h header file conditional to avoid that including that header file after <linux/blkdev.h> causes the compiler to complain about a SECTOR_SIZE redefinition. Note: the SECTOR_SIZE / SECTOR_SHIFT / SECTOR_BITS definitions have not been removed from uapi header files nor from NAND drivers in which these constants are used for another purpose than converting block layer offsets and sizes into a number of sectors. Cc: David S. Miller <davem@davemloft.net> Cc: Mike Snitzer <snitzer@redhat.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Nitin Gupta <ngupta@vflare.org> Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-03-09block: Use blk_queue_flag_*() in drivers instead of queue_flag_*()Bart Van Assche1-3/+3
This patch has been generated as follows: for verb in set_unlocked clear_unlocked set clear; do replace-in-files queue_flag_${verb} blk_queue_flag_${verb%_unlocked} \ $(git grep -lw queue_flag_${verb} drivers block/bsg*) done Except for protecting all queue flag changes with the queue lock this patch does not change any functionality. Cc: Mike Snitzer <snitzer@redhat.com> Cc: Shaohua Li <shli@fb.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Hannes Reinecke <hare@suse.de> Cc: Ming Lei <ming.lei@redhat.com> Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Acked-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-02-28zram: Delete gendisk before cleaning up the request queueBart Van Assche1-1/+1
Remove the disk, partition and bdi sysfs attributes before cleaning up the request queue associated with the disk. Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.com> Reviewed-by: Ming Lei <ming.lei@redhat.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Nitin Gupta <ngupta@vflare.org> Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-01-06block: convert to bio_first_bvec_all & bio_first_page_allMing Lei1-1/+1
This patch converts to bio_first_bvec_all() & bio_first_page_all() for retrieving the 1st bvec/page, and prepares for supporting multipage bvec. Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-11-16drivers/block/zram/zram_drv.c: make zram_page_end_io() staticColin Ian King1-1/+1
zram_page_end_io() is local to the source and does not need to be in global scope, so make it static. Cleans up sparse warning: symbol 'zram_page_end_io' was not declared. Should it be static? Link: http://lkml.kernel.org/r/20171016173336.20320-1-colin.king@canonical.com Signed-off-by: Colin Ian King <colin.king@canonical.com> Reviewed-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>
2017-11-16zram: remove zlib from the list of recommended algorithmsSergey Senozhatsky1-3/+0
ZSTD tends to outperform deflate/inflate, thus we remove zlib from the list of recommended algorithms and recommend zstd instead. Link: http://lkml.kernel.org/r/20170912050005.3247-2-sergey.senozhatsky@gmail.com Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Suggested-by: Minchan Kim <minchan@kernel.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>
2017-11-16zram: add zstd to the supported algorithms listSergey Senozhatsky1-0/+3
Add ZSTD to the list of supported compression algorithms. ZRAM fio perf test: LZO DEFLATE ZSTD #jobs1 WRITE: (2180MB/s) (77.2MB/s) (1429MB/s) WRITE: (1617MB/s) (77.7MB/s) (1202MB/s) READ: (426MB/s) (595MB/s) (1181MB/s) READ: (422MB/s) (572MB/s) (1020MB/s) READ: (318MB/s) (67.8MB/s) (563MB/s) WRITE: (318MB/s) (67.9MB/s) (564MB/s) READ: (336MB/s) (68.3MB/s) (583MB/s) WRITE: (335MB/s) (68.2MB/s) (582MB/s) #jobs2 WRITE: (3441MB/s) (152MB/s) (2141MB/s) WRITE: (2507MB/s) (147MB/s) (1888MB/s) READ: (801MB/s) (1146MB/s) (1890MB/s) READ: (767MB/s) (1096MB/s) (2073MB/s) READ: (621MB/s) (126MB/s) (1009MB/s) WRITE: (621MB/s) (126MB/s) (1009MB/s) READ: (656MB/s) (125MB/s) (1075MB/s) WRITE: (657MB/s) (126MB/s) (1077MB/s) #jobs3 WRITE: (4772MB/s) (225MB/s) (3394MB/s) WRITE: (3905MB/s) (211MB/s) (2939MB/s) READ: (1216MB/s) (1608MB/s) (3218MB/s) READ: (1159MB/s) (1431MB/s) (2981MB/s) READ: (906MB/s) (156MB/s) (1457MB/s) WRITE: (907MB/s) (156MB/s) (1458MB/s) READ: (953MB/s) (158MB/s) (1595MB/s) WRITE: (952MB/s) (157MB/s) (1593MB/s) #jobs4 WRITE: (6036MB/s) (265MB/s) (4469MB/s) WRITE: (5059MB/s) (263MB/s) (3951MB/s) READ: (1618MB/s) (2066MB/s) (4276MB/s) READ: (1573MB/s) (1942MB/s) (3830MB/s) READ: (1202MB/s) (227MB/s) (1971MB/s) WRITE: (1200MB/s) (227MB/s) (1968MB/s) READ: (1265MB/s) (226MB/s) (2116MB/s) WRITE: (1264MB/s) (226MB/s) (2114MB/s) #jobs5 WRITE: (5339MB/s) (233MB/s) (3781MB/s) WRITE: (4298MB/s) (234MB/s) (3276MB/s) READ: (1626MB/s) (2048MB/s) (4081MB/s) READ: (1567MB/s) (1929MB/s) (3758MB/s) READ: (1174MB/s) (205MB/s) (1747MB/s) WRITE: (1173MB/s) (204MB/s) (1746MB/s) READ: (1214MB/s) (208MB/s) (1890MB/s) WRITE: (1215MB/s) (208MB/s) (1892MB/s) #jobs6 WRITE: (5666MB/s) (270MB/s) (4338MB/s) WRITE: (4828MB/s) (267MB/s) (3772MB/s) READ: (1803MB/s) (2058MB/s) (4946MB/s) READ: (1805MB/s) (2156MB/s) (4711MB/s) READ: (1334MB/s) (235MB/s) (2135MB/s) WRITE: (1335MB/s) (235MB/s) (2137MB/s) READ: (1364MB/s) (236MB/s) (2268MB/s) WRITE: (1365MB/s) (237MB/s) (2270MB/s) #jobs7 WRITE: (5474MB/s) (270MB/s) (4300MB/s) WRITE: (4666MB/s) (266MB/s) (3817MB/s) READ: (2022MB/s) (2319MB/s) (5472MB/s) READ: (1924MB/s) (2260MB/s) (5031MB/s) READ: (1369MB/s) (242MB/s) (2153MB/s) WRITE: (1370MB/s) (242MB/s) (2155MB/s) READ: (1499MB/s) (246MB/s) (2310MB/s) WRITE: (1497MB/s) (246MB/s) (2307MB/s) #jobs8 WRITE: (5558MB/s) (273MB/s) (4439MB/s) WRITE: (4763MB/s) (271MB/s) (3918MB/s) READ: (2201MB/s) (2599MB/s) (6062MB/s) READ: (2105MB/s) (2463MB/s) (5413MB/s) READ: (1490MB/s) (252MB/s) (2238MB/s) WRITE: (1488MB/s) (252MB/s) (2236MB/s) READ: (1566MB/s) (254MB/s) (2434MB/s) WRITE: (1568MB/s) (254MB/s) (2437MB/s) #jobs9 WRITE: (5120MB/s) (264MB/s) (4035MB/s) WRITE: (4531MB/s) (267MB/s) (3740MB/s) READ: (1940MB/s) (2258MB/s) (4986MB/s) READ: (2024MB/s) (2387MB/s) (4871MB/s) READ: (1343MB/s) (246MB/s) (2038MB/s) WRITE: (1342MB/s) (246MB/s) (2037MB/s) READ: (1553MB/s) (238MB/s) (2243MB/s) WRITE: (1552MB/s) (238MB/s) (2242MB/s) #jobs10 WRITE: (5345MB/s) (271MB/s) (3988MB/s) WRITE: (4750MB/s) (254MB/s) (3668MB/s) READ: (1876MB/s) (2363MB/s) (5150MB/s) READ: (1990MB/s) (2256MB/s) (5080MB/s) READ: (1355MB/s) (250MB/s) (2019MB/s) WRITE: (1356MB/s) (251MB/s) (2020MB/s) READ: (1490MB/s) (252MB/s) (2202MB/s) WRITE: (1488MB/s) (252MB/s) (2199MB/s) jobs1 perfstat instructions 52,065,555,710 ( 0.79) 855,731,114,587 ( 2.64) 54,280,709,944 ( 1.40) branches 14,020,427,116 ( 725.847) 101,733,449,582 (1074.521) 11,170,591,067 ( 992.869) branch-misses 22,626,174 ( 0.16%) 274,197,885 ( 0.27%) 25,915,805 ( 0.23%) jobs2 perfstat instructions 103,633,110,402 ( 0.75) 1,710,822,100,914 ( 2.59) 107,879,874,104 ( 1.28) branches 27,931,237,282 ( 679.203) 203,298,267,479 (1037.326) 22,185,350,842 ( 884.427) branch-misses 46,103,811 ( 0.17%) 533,747,204 ( 0.26%) 49,682,483 ( 0.22%) jobs3 perfstat instructions 154,857,283,657 ( 0.76) 2,565,748,974,197 ( 2.57) 161,515,435,813 ( 1.31) branches 41,759,490,355 ( 670.529) 304,905,605,277 ( 978.765) 33,215,805,907 ( 888.003) branch-misses 74,263,293 ( 0.18%) 759,746,240 ( 0.25%) 76,841,196 ( 0.23%) jobs4 perfstat instructions 206,215,849,076 ( 0.75) 3,420,169,460,897 ( 2.60) 215,003,061,664 ( 1.31) branches 55,632,141,739 ( 666.501) 406,394,977,433 ( 927.241) 44,214,322,251 ( 883.532) branch-misses 102,287,788 ( 0.18%) 1,098,617,314 ( 0.27%) 103,891,040 ( 0.23%) jobs5 perfstat instructions 258,711,315,588 ( 0.67) 4,275,657,533,244 ( 2.23) 269,332,235,685 ( 1.08) branches 69,802,821,166 ( 588.823) 507,996,211,252 ( 797.036) 55,450,846,129 ( 735.095) branch-misses 129,217,214 ( 0.19%) 1,243,284,991 ( 0.24%) 173,512,278 ( 0.31%) jobs6 perfstat instructions 312,796,166,008 ( 0.61) 5,133,896,344,660 ( 2.02) 323,658,769,588 ( 1.04) branches 84,372,488,583 ( 520.541) 610,310,494,402 ( 697.642) 66,683,292,992 ( 693.939) branch-misses 159,438,978 ( 0.19%) 1,396,368,563 ( 0.23%) 174,406,934 ( 0.26%) jobs7 perfstat instructions 363,211,372,930 ( 0.56) 5,988,205,600,879 ( 1.75) 377,824,674,156 ( 0.93) branches 98,057,013,765 ( 463.117) 711,841,255,974 ( 598.762) 77,879,009,954 ( 600.443) branch-misses 199,513,153 ( 0.20%) 1,507,651,077 ( 0.21%) 248,203,369 ( 0.32%) jobs8 perfstat instructions 413,960,354,615 ( 0.52) 6,842,918,558,378 ( 1.45) 431,938,486,581 ( 0.83) branches 111,812,574,884 ( 414.224) 813,299,084,518 ( 491.173) 89,062,699,827 ( 517.795) branch-misses 233,584,845 ( 0.21%) 1,531,593,921 ( 0.19%) 286,818,489 ( 0.32%) jobs9 perfstat instructions 465,976,220,300 ( 0.53) 7,698,467,237,372 ( 1.47) 486,352,600,321 ( 0.84) branches 125,931,456,162 ( 424.063) 915,207,005,715 ( 498.192) 100,370,404,090 ( 517.439) branch-misses 256,992,445 ( 0.20%) 1,782,809,816 ( 0.19%) 345,239,380 ( 0.34%) jobs10 perfstat instructions 517,406,372,715 ( 0.53) 8,553,527,312,900 ( 1.48) 540,732,653,094 ( 0.84) branches 139,839,780,676 ( 427.732) 1,016,737,699,389 ( 503.172) 111,696,557,638 ( 516.750) branch-misses 259,595,561 ( 0.19%) 1,952,570,279 ( 0.19%) 357,818,661 ( 0.32%) seconds elapsed 20.630411534 96.084546565 12.743373571 seconds elapsed 22.292627625 100.984155001 14.407413560 seconds elapsed 22.396016966 110.344880848 14.032201392 seconds elapsed 22.517330949 113.351459170 14.243074935 seconds elapsed 28.548305104 156.515193765 19.159286861 seconds elapsed 30.453538116 164.559937678 19.362492717 seconds elapsed 33.467108086 188.486827481 21.492612173 seconds elapsed 35.617727591 209.602677783 23.256422492 seconds elapsed 42.584239509 243.959902566 28.458540338 seconds elapsed 47.683632526 269.635248851 31.542404137 Over all, ZSTD has slower WRITE, but much faster READ (perhaps a static compression buffer used during the test helped ZSTD a lot), which results in faster test results. Memory consumption (zram mm_stat file): zram LZO mm_stat mm_stat (jobs1): 2147483648 23068672 33558528 0 33558528 0 0 mm_stat (jobs2): 2147483648 23068672 33558528 0 33558528 0 0 mm_stat (jobs3): 2147483648 23068672 33558528 0 33562624 0 0 mm_stat (jobs4): 2147483648 23068672 33558528 0 33558528 0 0 mm_stat (jobs5): 2147483648 23068672 33558528 0 33558528 0 0 mm_stat (jobs6): 2147483648 23068672 33558528 0 33562624 0 0 mm_stat (jobs7): 2147483648 23068672 33558528 0 33566720 0 0 mm_stat (jobs8): 2147483648 23068672 33558528 0 33558528 0 0 mm_stat (jobs9): 2147483648 23068672 33558528 0 33558528 0 0 mm_stat (jobs10): 2147483648 23068672 33558528 0 33562624 0 0 zram DEFLATE mm_stat mm_stat (jobs1): 2147483648 16252928 25178112 0 25178112 0 0 mm_stat (jobs2): 2147483648 16252928 25178112 0 25178112 0 0 mm_stat (jobs3): 2147483648 16252928 25178112 0 25178112 0 0 mm_stat (jobs4): 2147483648 16252928 25178112 0 25178112 0 0 mm_stat (jobs5): 2147483648 16252928 25178112 0 25178112 0 0 mm_stat (jobs6): 2147483648 16252928 25178112 0 25178112 0 0 mm_stat (jobs7): 2147483648 16252928 25178112 0 25190400 0 0 mm_stat (jobs8): 2147483648 16252928 25178112 0 25190400 0 0 mm_stat (jobs9): 2147483648 16252928 25178112 0 25178112 0 0 mm_stat (jobs10): 2147483648 16252928 25178112 0 25178112 0 0 zram ZSTD mm_stat mm_stat (jobs1): 2147483648 11010048 16781312 0 16781312 0 0 mm_stat (jobs2): 2147483648 11010048 16781312 0 16781312 0 0 mm_stat (jobs3): 2147483648 11010048 16781312 0 16785408 0 0 mm_stat (jobs4): 2147483648 11010048 16781312 0 16781312 0 0 mm_stat (jobs5): 2147483648 11010048 16781312 0 16781312 0 0 mm_stat (jobs6): 2147483648 11010048 16781312 0 16781312 0 0 mm_stat (jobs7): 2147483648 11010048 16781312 0 16781312 0 0 mm_stat (jobs8): 2147483648 11010048 16781312 0 16781312 0 0 mm_stat (jobs9): 2147483648 11010048 16781312 0 16785408 0 0 mm_stat (jobs10): 2147483648 11010048 16781312 0 16781312 0 0 ================================================================================== Official benchmarks [1]: Compressor name Ratio Compression Decompress. zstd 1.1.3 -1 2.877 430 MB/s 1110 MB/s zlib 1.2.8 -1 2.743 110 MB/s 400 MB/s brotli 0.5.2 -0 2.708 400 MB/s 430 MB/s quicklz 1.5.0 -1 2.238 550 MB/s 710 MB/s lzo1x 2.09 -1 2.108 650 MB/s 830 MB/s lz4 1.7.5 2.101 720 MB/s 3600 MB/s snappy 1.1.3 2.091 500 MB/s 1650 MB/s lzf 3.6 -1 2.077 400 MB/s 860 MB/s Minchan said: : I did test with my sample data and compared zstd with deflate. zstd's : compress ratio is lower a little bit but compression speed is much faster : 3 times more and decompress speed is too 2 times more. With different : data, it is different but overall, zstd would be better for speed at the : cost of a little lower compress ratio(about 5%) so I believe it's worth to : replace deflate. [1] https://github.com/facebook/zstd Link: http://lkml.kernel.org/r/20170912050005.3247-1-sergey.senozhatsky@gmail.com Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Acked-by: Minchan Kim <minchan@kernel.org> Tested-by: Minchan Kim <minchan@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-11-16bdi: introduce BDI_CAP_SYNCHRONOUS_IOMinchan Kim1-1/+1
As discussed at https://lkml.kernel.org/r/<20170728165604.10455-1-ross.zwisler@linux.intel.com> someday we will remove rw_page(). If so, we need something to detect such super-fast storage on which synchronous IO operations like the current rw_page are always a win. Introduces BDI_CAP_SYNCHRONOUS_IO to indicate such devices. With it, we could use various optimization techniques. Link: http://lkml.kernel.org/r/1505886205-9671-3-git-send-email-minchan@kernel.org Signed-off-by: Minchan Kim <minchan@kernel.org> Cc: Christoph Hellwig <hch@lst.de> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Cc: Hugh Dickins <hughd@google.com> Cc: Ilya Dryomov <idryomov@gmail.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: Huang Ying <ying.huang@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-11-16zram: set BDI_CAP_STABLE_WRITES onceMinchan Kim1-10/+6
With fast swap storage, the platform wants to use swap more aggressively and swap-in is crucial to application latency. The rw_page() based synchronous devices like zram, pmem and btt are such fast storage. When I profile swapin performance with zram lz4 decompress test, S/W overhead is more than 70%. Maybe, it would be bigger in nvdimm. This patchset reduces swap-in latency by skipping swapcache if the swap device is a synchronous device like a rw_page() based device. It enhances by 45% my swapin test (5G sequential swapin, no readahead) from 2.41sec to 1.64sec. This patch (of 4): Commit 19b7ccf8651d ("block: get rid of blk_integrity_revalidate()") fixed a weird thing (i.e., reset BDI_CAP_STABLE_WRITES flag unconditionally whenever revalidat_disk is called) so zram doesn't need to reset the flag any more when revalidating the bdev. Instead, set the flag just once when the zram device is created. It shouldn't change any behavior. Link: http://lkml.kernel.org/r/1505886205-9671-2-git-send-email-minchan@kernel.org Signed-off-by: Minchan Kim <minchan@kernel.org> Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: Ilya Dryomov <idryomov@gmail.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Hugh Dickins <hughd@google.com> Cc: Huang Ying <ying.huang@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-11-02License cleanup: add SPDX GPL-2.0 license identifier to files with no licenseGreg Kroah-Hartman1-0/+1
Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-10-04zram: fix null dereference of handleMinchan Kim1-24/+12
In testing I found handle passed to zs_map_object in __zram_bvec_read is NULL so eh kernel goes oops in pin_object(). The reason is there is no routine to check the slot's freeing after getting the slot's lock. This patch fixes it. [minchan@kernel.org: v2] Link: http://lkml.kernel.org/r/1505887347-10881-1-git-send-email-minchan@kernel.org Link: http://lkml.kernel.org/r/1505788488-26723-1-git-send-email-minchan@kernel.org Fixes: 1f7319c74275 ("zram: partial IO refactoring") Signed-off-by: Minchan Kim <minchan@kernel.org> Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-09-09drivers/block/zram/zram_drv.c: convert to using memset_lMatthew Wilcox1-11/+2
zram was the motivation for creating memset_l(). Minchan Kim sees a 7% performance improvement on x86 with 100MB of non-zero deduplicatable data: perf stat -r 10 dd if=/dev/zram0 of=/dev/null vanilla: 0.232050465 seconds time elapsed ( +- 0.51% ) memset_l: 0.217219387 seconds time elapsed ( +- 0.07% ) Link: http://lkml.kernel.org/r/20170720184539.31609-7-willy@infradead.org Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com> Tested-by: Minchan Kim <minchan@kernel.org> Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: "James E.J. Bottomley" <jejb@linux.vnet.ibm.com> Cc: "Martin K. Petersen" <martin.petersen@oracle.com> Cc: David Miller <davem@davemloft.net> Cc: Ingo Molnar <mingo@elte.hu> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: Matt Turner <mattst88@gmail.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Richard Henderson <rth@twiddle.net> Cc: Russell King <rmk+kernel@armlinux.org.uk> Cc: Sam Ravnborg <sam@ravnborg.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-09-07Merge branch 'for-4.14/block' of git://git.kernel.dk/linux-blockLinus Torvalds1-4/+5
Pull block layer updates from Jens Axboe: "This is the first pull request for 4.14, containing most of the code changes. It's a quiet series this round, which I think we needed after the churn of the last few series. This contains: - Fix for a registration race in loop, from Anton Volkov. - Overflow complaint fix from Arnd for DAC960. - Series of drbd changes from the usual suspects. - Conversion of the stec/skd driver to blk-mq. From Bart. - A few BFQ improvements/fixes from Paolo. - CFQ improvement from Ritesh, allowing idling for group idle. - A few fixes found by Dan's smatch, courtesy of Dan. - A warning fixup for a race between changing the IO scheduler and device remova. From David Jeffery. - A few nbd fixes from Josef. - Support for cgroup info in blktrace, from Shaohua. - Also from Shaohua, new features in the null_blk driver to allow it to actually hold data, among other things. - Various corner cases and error handling fixes from Weiping Zhang. - Improvements to the IO stats tracking for blk-mq from me. Can drastically improve performance for fast devices and/or big machines. - Series from Christoph removing bi_bdev as being needed for IO submission, in preparation for nvme multipathing code. - Series from Bart, including various cleanups and fixes for switch fall through case complaints" * 'for-4.14/block' of git://git.kernel.dk/linux-block: (162 commits) kernfs: checking for IS_ERR() instead of NULL drbd: remove BIOSET_NEED_RESCUER flag from drbd_{md_,}io_bio_set drbd: Fix allyesconfig build, fix recent commit drbd: switch from kmalloc() to kmalloc_array() drbd: abort drbd_start_resync if there is no connection drbd: move global variables to drbd namespace and make some static drbd: rename "usermode_helper" to "drbd_usermode_helper" drbd: fix race between handshake and admin disconnect/down drbd: fix potential deadlock when trying to detach during handshake drbd: A single dot should be put into a sequence. drbd: fix rmmod cleanup, remove _all_ debugfs entries drbd: Use setup_timer() instead of init_timer() to simplify the code. drbd: fix potential get_ldev/put_ldev refcount imbalance during attach drbd: new disk-option disable-write-same drbd: Fix resource role for newly created resources in events2 drbd: mark symbols static where possible drbd: Send P_NEG_ACK upon write error in protocol != C drbd: add explicit plugging when submitting batches drbd: change list_for_each_safe to while(list_first_entry_or_null) drbd: introduce drbd_recv_header_maybe_unplug ...
2017-09-07block, THP: make block_device_operations.rw_page support THPHuang Ying1-0/+2
The .rw_page in struct block_device_operations is used by the swap subsystem to read/write the page contents from/into the corresponding swap slot in the swap device. To support the THP (Transparent Huge Page) swap optimization, the .rw_page is enhanced to support to read/write THP if possible. Link: http://lkml.kernel.org/r/20170724051840.2309-6-ying.huang@intel.com Signed-off-by: "Huang, Ying" <ying.huang@intel.com> Reviewed-by: Ross Zwisler <ross.zwisler@intel.com> [for brd.c, zram_drv.c, pmem.c] Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Vishal L Verma <vishal.l.verma@intel.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Rik van Riel <riel@redhat.com> Cc: Shaohua Li <shli@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-09-07zram: add config and doc file for writeback featureMinchan Kim1-0/+12
This patch adds document and kconfig for using of writeback feature. Link: http://lkml.kernel.org/r/1498459987-24562-10-git-send-email-minchan@kernel.org Signed-off-by: Minchan Kim <minchan@kernel.org> Cc: Juneho Choi <juno.choi@lge.com> Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
generated by cgit v1.2.3 (git 2.39.0) at 2024-12-13 02:46:35 +0300