- 06 5月, 2015 1 次提交
-
-
由 Andrew Morton 提交于
Revert commit c72c6160 It was intended to be a cosmetic change that w/o any functional change and was part of a bigger change: http://lkml.iu.edu/hypermail/linux/kernel/1503.1/01818.html Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Nitin Gupta <ngupta@vflare.org> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
-
- 16 4月, 2015 8 次提交
-
-
由 Julia Lawall 提交于
Return a negative error code on failure. A simplified version of the semantic match that finds this problem is as follows: (http://coccinelle.lip6.fr/) // <smpl> @@ identifier ret; expression e1,e2; @@ ( if (\(ret < 0\|ret != 0\)) { ... return ret; } | ret = 0 ) ... when != ret = e1 when != &ret *if(...) { ... when != ret = e2 when forall return ret; } // </smpl> Signed-off-by: NJulia Lawall <Julia.Lawall@lip6.fr> Cc: Minchan Kim <minchan@kernel.org> Cc: Nitin Gupta <ngupta@vflare.org> Acked-by: NSergey Senozhatsky <sergey.senozhatsky.work@gmail.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
-
由 Sergey Senozhatsky 提交于
Add Documentation/ABI/obsolete/sysfs-block-zram file and list obsolete and deprecated attributes there. The patch also adds additional information to zram documentation and describes the basic strategy: - the existing RW nodes will be downgraded to WO nodes (in 4.11) - deprecated RO sysfs nodes will eventually be removed (in 4.11) Users will be additionally notified about deprecated attr usage by pr_warn_once() (added to every deprecated attr _show()), as suggested by Minchan Kim. User space is advised to use zram<id>/stat, zram<id>/io_stat and zram<id>/mm_stat files. Signed-off-by: NSergey Senozhatsky <sergey.senozhatsky@gmail.com> Reported-by: NMinchan Kim <minchan@kernel.org> Cc: Nitin Gupta <ngupta@vflare.org> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
-
由 Sergey Senozhatsky 提交于
Per-device `zram<id>/mm_stat' file provides mm statistics of a particular zram device in a format similar to block layer statistics. The file consists of a single line and represents the following stats (separated by whitespace): orig_data_size compr_data_size mem_used_total mem_limit mem_used_max zero_pages num_migrated Signed-off-by: NSergey Senozhatsky <sergey.senozhatsky@gmail.com> Acked-by: NMinchan Kim <minchan@kernel.org> Cc: Nitin Gupta <ngupta@vflare.org> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
-
由 Sergey Senozhatsky 提交于
Per-device `zram<id>/io_stat' file provides accumulated I/O statistics of particular zram device in a format similar to block layer statistics. The file consists of a single line and represents the following stats (separated by whitespace): failed_reads failed_writes invalid_io notify_free Signed-off-by: NSergey Senozhatsky <sergey.senozhatsky@gmail.com> Acked-by: NMinchan Kim <minchan@kernel.org> Cc: Nitin Gupta <ngupta@vflare.org> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
-
由 Sergey Senozhatsky 提交于
Use bio generic_start_io_acct() and generic_end_io_acct() to account device's block layer statistics. This will let users to monitor zram activities using sysstat and similar packages/tools. Apart from the usual per-stat sysfs attr, zram IO stats are now also available in '/sys/block/zram<id>/stat' and '/proc/diskstats' files. We will slowly get rid of per-stat sysfs files. Signed-off-by: NSergey Senozhatsky <sergey.senozhatsky@gmail.com> Acked-by: NMinchan Kim <minchan@kernel.org> Cc: Nitin Gupta <ngupta@vflare.org> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
-
由 Sergey Senozhatsky 提交于
A cosmetic change. We have a new code layout and keep zram per-device sysfs store and show functions in one place. Move compact_store() to that handlers block to conform to current layout. Signed-off-by: NSergey Senozhatsky <sergey.senozhatsky@gmail.com> Acked-by: NMinchan Kim <minchan@kernel.org> Cc: Nitin Gupta <ngupta@vflare.org> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
-
由 Sergey Senozhatsky 提交于
This patch introduces rework to zram stats. We have per-stat sysfs nodes, and it makes things a bit hard to use in user space: it doesn't give an immediate stats 'snapshot', it requires user space to use more syscalls - open, read, close for every stat file, with appropriate error checks on every step, etc. First, zram now accounts block layer statistics, available in /sys/block/zram<id>/stat and /proc/diskstats files. So some new stats are available (see Documentation/block/stat.txt), besides, zram's activities now can be monitored by sysstat's iostat or similar tools. Example: cat /sys/block/zram0/stat 248 0 1984 0 251029 0 2008232 5120 0 5116 5116 Second, group currently exported on per-stat basis nodes into two categories (files): -- zram<id>/io_stat accumulates device's IO stats, that are not accounted by block layer, and contains: failed_reads failed_writes invalid_io notify_free Example: cat /sys/block/zram0/io_stat 0 0 0 652572 -- zram<id>/mm_stat accumulates zram mm stats and contains: orig_data_size compr_data_size mem_used_total mem_limit mem_used_max zero_pages num_migrated Example: cat /sys/block/zram0/mm_stat 434634752 270288572 279158784 0 579895296 15060 0 per-stat sysfs nodes are now considered to be deprecated and we plan to remove them (and clean up some of the existing stat code) in two years (as of now, there is no warning printed to syslog about deprecated stats being used). User space is advised to use the above mentioned 3 files. This patch (of 7): Remove sysfs `num_migrated' attribute. We are moving away from per-stat device attrs towards 3 stat files that will accumulate io and mm stats in a format similar to block layer statistics in /sys/block/<dev>/stat. That will be easier to use in user space, and reduce the number of syscalls needed to read zram device statistics. `num_migrated' will return back in zram<id>/mm_stat file. Signed-off-by: NSergey Senozhatsky <sergey.senozhatsky@gmail.com> Acked-by: NMinchan Kim <minchan@kernel.org> Cc: Nitin Gupta <ngupta@vflare.org> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
-
由 Minchan Kim 提交于
Now that zsmalloc supports compaction, zram can use it. For the first step, this patch exports compact knob via sysfs so user can do compaction via "echo 1 > /sys/block/zram0/compact". Signed-off-by: NMinchan Kim <minchan@kernel.org> Cc: Juneho Choi <juno.choi@lge.com> Cc: Gunho Lee <gunho.lee@lge.com> Cc: Luigi Semenzato <semenzato@google.com> Cc: Dan Streetman <ddstreet@ieee.org> Cc: Seth Jennings <sjennings@variantweb.net> Cc: Nitin Gupta <ngupta@vflare.org> Cc: Jerome Marchand <jmarchan@redhat.com> Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Mel Gorman <mel@csn.ul.ie> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
-
- 01 3月, 2015 1 次提交
-
-
由 Joonsoo Kim 提交于
max_used_pages is defined as atomic_long_t so we need to use unsigned long to keep temporary value for it rather than int which is smaller than unsigned long in a 64 bit system. Signed-off-by: NJoonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Jerome Marchand <jmarchan@redhat.com> Cc: Nitin Gupta <ngupta@vflare.org> Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
-
- 13 2月, 2015 8 次提交
-
-
由 Ganesh Mahendran 提交于
Currently the underlay of zpool: zsmalloc/zbud, do not know who creates them. There is not a method to let zsmalloc/zbud find which caller they belong to. Now we want to add statistics collection in zsmalloc. We need to name the debugfs dir for each pool created. The way suggested by Minchan Kim is to use a name passed by caller(such as zram) to create the zsmalloc pool. /sys/kernel/debug/zsmalloc/zram0 This patch adds an argument `name' to zs_create_pool() and other related functions. Signed-off-by: NGanesh Mahendran <opensource.ganesh@gmail.com> Acked-by: NMinchan Kim <minchan@kernel.org> Cc: Seth Jennings <sjennings@variantweb.net> Cc: Nitin Gupta <ngupta@vflare.org> Cc: Dan Streetman <ddstreet@ieee.org> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
-
由 Sergey Senozhatsky 提交于
`struct zram' contains both `struct gendisk' and `struct request_queue'. the latter can be deleted, because zram->disk carries ->queue pointer, and ->queue carries zram pointer: create_device() zram->queue->queuedata = zram zram->disk->queue = zram->queue zram->disk->private_data = zram so zram->queue is not needed, we can access all necessary data anyway. Signed-off-by: NSergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Jerome Marchand <jmarchan@redhat.com> Cc: Nitin Gupta <ngupta@vflare.org> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
-
由 Minchan Kim 提交于
Admin could reset zram during I/O operation going on so we have used zram->init_lock as read-side lock in I/O path to prevent sudden zram meta freeing. However, the init_lock is really troublesome. We can't do call zram_meta_alloc under init_lock due to lockdep splat because zram_rw_page is one of the function under reclaim path and hold it as read_lock while other places in process context hold it as write_lock. So, we have used allocation out of the lock to avoid lockdep warn but it's not good for readability and fainally, I met another lockdep splat between init_lock and cpu_hotplug from kmem_cache_destroy during working zsmalloc compaction. :( Yes, the ideal is to remove horrible init_lock of zram in rw path. This patch removes it in rw path and instead, add atomic refcount for meta lifetime management and completion to free meta in process context. It's important to free meta in process context because some of resource destruction needs mutex lock, which could be held if we releases the resource in reclaim context so it's deadlock, again. As a bonus, we could remove init_done check in rw path because zram_meta_get will do a role for it, instead. Signed-off-by: NSergey Senozhatsky <sergey.senozhatsky@gmail.com> Signed-off-by: NMinchan Kim <minchan@kernel.org> Cc: Nitin Gupta <ngupta@vflare.org> Cc: Jerome Marchand <jmarchan@redhat.com> Cc: Ganesh Mahendran <opensource.ganesh@gmail.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
-
由 Minchan Kim 提交于
bd_holders is increased only when user open the device file as FMODE_EXCL so if something opens zram0 as !FMODE_EXCL and request I/O while another user reset zram0, we can see following warning. zram0: detected capacity change from 0 to 64424509440 Buffer I/O error on dev zram0, logical block 180823, lost async page write Buffer I/O error on dev zram0, logical block 180824, lost async page write Buffer I/O error on dev zram0, logical block 180825, lost async page write Buffer I/O error on dev zram0, logical block 180826, lost async page write Buffer I/O error on dev zram0, logical block 180827, lost async page write Buffer I/O error on dev zram0, logical block 180828, lost async page write Buffer I/O error on dev zram0, logical block 180829, lost async page write Buffer I/O error on dev zram0, logical block 180830, lost async page write Buffer I/O error on dev zram0, logical block 180831, lost async page write Buffer I/O error on dev zram0, logical block 180832, lost async page write ------------[ cut here ]------------ WARNING: CPU: 11 PID: 1996 at fs/block_dev.c:57 __blkdev_put+0x1d7/0x210() Modules linked in: CPU: 11 PID: 1996 Comm: dd Not tainted 3.19.0-rc6-next-20150202+ #1125 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 Call Trace: dump_stack+0x45/0x57 warn_slowpath_common+0x8a/0xc0 warn_slowpath_null+0x1a/0x20 __blkdev_put+0x1d7/0x210 blkdev_put+0x50/0x130 blkdev_close+0x25/0x30 __fput+0xdf/0x1e0 ____fput+0xe/0x10 task_work_run+0xa7/0xe0 do_notify_resume+0x49/0x60 int_signal+0x12/0x17 ---[ end trace 274fbbc5664827d2 ]--- The warning comes from bdev_write_node in blkdev_put path. static void bdev_write_inode(struct inode *inode) { spin_lock(&inode->i_lock); while (inode->i_state & I_DIRTY) { spin_unlock(&inode->i_lock); WARN_ON_ONCE(write_inode_now(inode, true)); <========= here. spin_lock(&inode->i_lock); } spin_unlock(&inode->i_lock); } The reason is dd process encounters I/O fails due to sudden block device disappear so in filemap_check_errors in __writeback_single_inode returns -EIO. If we check bd_openers instead of bd_holders, we could address the problem. When I see the brd, it already have used it rather than bd_holders so although I'm not a expert of block layer, it seems to be better. I can make following warning with below simple script. In addition, I added msleep(2000) below set_capacity(zram->disk, 0) after applying your patch to make window huge(Kudos to Ganesh!) script: echo $((60<<30)) > /sys/block/zram0/disksize setsid dd if=/dev/zero of=/dev/zram0 & sleep 1 setsid echo 1 > /sys/block/zram0/reset Signed-off-by: NMinchan Kim <minchan@kernel.org> Acked-by: NSergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: Nitin Gupta <ngupta@vflare.org> Cc: Jerome Marchand <jmarchan@redhat.com> Cc: Ganesh Mahendran <opensource.ganesh@gmail.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
-
由 Sergey Senozhatsky 提交于
We need to return set_capacity(disk, 0) from reset_store() back to zram_reset_device(), a catch by Ganesh Mahendran. Potentially, we can race set_capacity() calls from init and reset paths. The problem is that zram_reset_device() is also getting called from zram_exit(), which performs operations in misleading reversed order -- we first create_device() and then init it, while zram_exit() perform destroy_device() first and then does zram_reset_device(). This is done to remove sysfs group before we reset device, so we can continue with device reset/destruction not being raced by sysfs attr write (f.e. disksize). Apart from that, destroy_device() releases zram->disk (but we still have ->disk pointer), so we cannot acces zram->disk in later zram_reset_device() call, which may cause additional errors in the future. So, this patch rework and cleanup destroy path. 1) remove several unneeded goto labels in zram_init() 2) factor out zram_init() error path and zram_exit() into destroy_devices() function, which takes the number of devices to destroy as its argument. 3) remove sysfs group in destroy_devices() first, so we can reorder operations -- reset device (as expected) goes before disk destroy and queue cleanup. So we can always access ->disk in zram_reset_device(). 4) and, finally, return set_capacity() back under ->init_lock. [akpm@linux-foundation.org: tweak comment] Signed-off-by: NSergey Senozhatsky <sergey.senozhatsky@gmail.com> Reported-by: NGanesh Mahendran <opensource.ganesh@gmail.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Jerome Marchand <jmarchan@redhat.com> Cc: Nitin Gupta <ngupta@vflare.org> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
-
由 Sergey Senozhatsky 提交于
Ganesh Mahendran was the first one who proposed to use bdev->bd_mutex to avoid ->bd_holders race condition: CPU0 CPU1 umount /* zram->init_done is true */ reset_store() bdev->bd_holders == 0 mount ... zram_make_request() zram_reset_device() However, his solution required some considerable amount of code movement, which we can avoid. Apart from using bdev->bd_mutex in reset_store(), this patch also simplifies zram_reset_device(). zram_reset_device() has a bool parameter reset_capacity which tells it whether disk capacity and itself disk should be reset. There are two zram_reset_device() callers: -- zram_exit() passes reset_capacity=false -- reset_store() passes reset_capacity=true So we can move reset_capacity-sensitive work out of zram_reset_device() and perform it unconditionally in reset_store(). This also lets us drop reset_capacity parameter from zram_reset_device() and pass zram pointer only. Signed-off-by: NSergey Senozhatsky <sergey.senozhatsky@gmail.com> Reported-by: NGanesh Mahendran <opensource.ganesh@gmail.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
-
由 Ganesh Mahendran 提交于
zram_meta_alloc() and zram_meta_free() are a pair. In zram_meta_alloc(), meta table is allocated. So it it better to free it in zram_meta_free(). Signed-off-by: NGanesh Mahendran <opensource.ganesh@gmail.com> Acked-by: NMinchan Kim <minchan@kernel.org> Acked-by: NSergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: Nitin Gupta <ngupta@vflare.org> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
-
由 Sergey Senozhatsky 提交于
A trivial cleanup of zram_meta_alloc() error handling. Signed-off-by: NSergey Senozhatsky <sergey.senozhatsky@gmail.com> Acked-by: NMinchan Kim <minchan@kernel.org> Cc: Nitin Gupta <ngupta@vflare.org> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
-
- 14 12月, 2014 4 次提交
-
-
由 Ganesh Mahendran 提交于
In current zram, we use DEVICE_ATTR() to define sys device attributes. SO, we need to set (S_IRUGO | S_IWUSR) permission and other arguments manually. Linux already provids the macro DEVICE_ATTR_[RW|RO|WO] to define sys device attribute. It is simple and readable. This patch uses kernel defined macro DEVICE_ATTR_[RW|RO|WO] to define zram device attribute. Signed-off-by: NGanesh Mahendran <opensource.ganesh@gmail.com> Acked-by: NJerome Marchand <jmarchan@redhat.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Nitin Gupta <ngupta@vflare.org> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
-
由 karam.lee 提交于
This patch implements rw_page operation for zram block device. I implemented the feature in zram and tested it. Test bed was the G2, LG electronic mobile device, whtich has msm8974 processor and 2GB memory. With a memory allocation test program consuming memory, the system generates swap. Operating time of swap_write_page() was measured. -------------------------------------------------- | | operating time | improvement | | | (20 runs average) | | -------------------------------------------------- |with patch | 1061.15 us | +2.4% | -------------------------------------------------- |without patch| 1087.35 us | | -------------------------------------------------- Each test(with paged_io,with BIO) result set shows normal distribution and has equal variance. I mean the two values are valid result to compare. I can say operation with paged I/O(without BIO) is faster 2.4% with confidence level 95%. [minchan@kernel.org: make rw_page opeartion return 0] [minchan@kernel.org: rely on the bi_end_io for zram_rw_page fails] [sergey.senozhatsky@gmail.com: code cleanup] [minchan@kernel.org: add comment] Signed-off-by: Nkaram.lee <karam.lee@lge.com> Acked-by: NMinchan Kim <minchan@kernel.org> Acked-by: NJerome Marchand <jmarchan@redhat.com> Cc: Matthew Wilcox <matthew.r.wilcox@intel.com> Cc: Nitin Gupta <ngupta@vflare.org> Cc: <seungho1.park@lge.com> Signed-off-by: NMinchan Kim <minchan@kernel.org> Signed-off-by: NSergey Senozhatsky <sergey.senozhatsky@gmail.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
-
由 karam.lee 提交于
This patch changes parameter of valid_io_request for common usage. The purpose of valid_io_request() is to determine if bio request is valid or not. This patch use I/O start address and size instead of a BIO parameter for common usage. Signed-off-by: Nkaram.lee <karam.lee@lge.com> Acked-by: NMinchan Kim <minchan@kernel.org> Acked-by: NJerome Marchand <jmarchan@redhat.com> Cc: Matthew Wilcox <matthew.r.wilcox@intel.com> Cc: Nitin Gupta <ngupta@vflare.org> Cc: <seungho1.park@lge.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
-
由 karam.lee 提交于
Recently rw_page block device operation has been added. This patchset implements rw_page operation for zram block device and does some clean-up. This patch (of 3): Remove an unnecessary parameter(bio) from zram_bvec_rw() and zram_bvec_read(). zram_bvec_read() doesn't use a bio parameter, so remove it. zram_bvec_rw() calls a read/write operation not using bio, so a rw parameter replaces a bio parameter. Signed-off-by: Nkaram.lee <karam.lee@lge.com> Acked-by: NMinchan Kim <minchan@kernel.org> Acked-by: NJerome Marchand <jmarchan@redhat.com> Cc: Matthew Wilcox <matthew.r.wilcox@intel.com> Cc: Nitin Gupta <ngupta@vflare.org> Cc: <seungho1.park@lge.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
-
- 14 11月, 2014 1 次提交
-
-
由 Weijie Yang 提交于
zram could kunmap_atomic() a NULL pointer in a rare situation: a zram page becomes a full-zeroed page after a partial write io. The current code doesn't handle this case and performs kunmap_atomic() on a NULL pointer, which panics the kernel. This patch fixes this issue. Signed-off-by: NWeijie Yang <weijie.yang@samsung.com> Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: Dan Streetman <ddstreet@ieee.org> Cc: Nitin Gupta <ngupta@vflare.org> Cc: Weijie Yang <weijie.yang.kh@gmail.com> Acked-by: NJerome Marchand <jmarchan@redhat.com> Cc: <stable@vger.kernel.org> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
-
- 30 10月, 2014 1 次提交
-
-
由 Weijie Yang 提交于
There is a rare NULL pointer bug in mem_used_total_show() and mem_used_max_store() in concurrent situation, like this: zram is not initialized, process A is a mem_used_total reader which runs periodically, while process B try to init zram. process A process B access meta, get a NULL value init zram, done init_done() is true access meta->mem_pool, get a NULL pointer BUG This patch fixes this issue. Signed-off-by: NWeijie Yang <weijie.yang@samsung.com> Acked-by: NMinchan Kim <minchan@kernel.org> Acked-by: NSergey Senozhatsky <sergey.senozhatsky@gmail.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
-
- 10 10月, 2014 4 次提交
-
-
由 Sergey Senozhatsky 提交于
`notify_free' device attribute accounts the number of slot free notifications and internally represents the number of zram_free_page() calls. Slot free notifications are sent only when device is used as a swap device, hence `notify_free' is used only for swap devices. Since f4659d8e (zram: support REQ_DISCARD) ZRAM handles yet another one free notification (also via zram_free_page() call) -- REQ_DISCARD requests, which are sent by a filesystem, whenever some data blocks are discarded. However, there is no way to know the number of notifications in the latter case. Use `notify_free' to account the number of pages freed by zram_bio_discard() and zram_slot_free_notify(). Depending on usage scenario `notify_free' represents: a) the number of pages freed because of slot free notifications, which is equal to the number of swap_slot_free_notify() calls, so there is no behaviour change b) the number of pages freed because of REQ_DISCARD notifications Signed-off-by: NSergey Senozhatsky <sergey.senozhatsky@gmail.com> Acked-by: NMinchan Kim <minchan@kernel.org> Acked-by: NJerome Marchand <jmarchan@redhat.com> Cc: Nitin Gupta <ngupta@vflare.org> Cc: Chao Yu <chao2.yu@samsung.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
-
由 Minchan Kim 提交于
Normally, zram user could get maximum memory usage zram consumed via polling mem_used_total with sysfs in userspace. But it has a critical problem because user can miss peak memory usage during update inverval of polling. For avoiding that, user should poll it with shorter interval(ie, 0.0000000001s) with mlocking to avoid page fault delay when memory pressure is heavy. It would be troublesome. This patch adds new knob "mem_used_max" so user could see the maximum memory usage easily via reading the knob and reset it via "echo 0 > /sys/block/zram0/mem_used_max". Signed-off-by: NMinchan Kim <minchan@kernel.org> Reviewed-by: NDan Streetman <ddstreet@ieee.org> Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: Jerome Marchand <jmarchan@redhat.com> Cc: <juno.choi@lge.com> Cc: <seungho1.park@lge.com> Cc: Luigi Semenzato <semenzato@google.com> Cc: Nitin Gupta <ngupta@vflare.org> Cc: Seth Jennings <sjennings@variantweb.net> Reviewed-by: NDavid Horner <ds2horner@gmail.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
-
由 Minchan Kim 提交于
Since zram has no control feature to limit memory usage, it makes hard to manage system memrory. This patch adds new knob "mem_limit" via sysfs to set up the a limit so that zram could fail allocation once it reaches the limit. In addition, user could change the limit in runtime so that he could manage the memory more dynamically. Initial state is no limit so it doesn't break old behavior. [akpm@linux-foundation.org: fix typo, per Sergey] Signed-off-by: NMinchan Kim <minchan@kernel.org> Cc: Dan Streetman <ddstreet@ieee.org> Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: Jerome Marchand <jmarchan@redhat.com> Cc: <juno.choi@lge.com> Cc: <seungho1.park@lge.com> Cc: Luigi Semenzato <semenzato@google.com> Cc: Nitin Gupta <ngupta@vflare.org> Cc: Seth Jennings <sjennings@variantweb.net> Cc: David Horner <ds2horner@gmail.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Minchan Kim <minchan@kernel.org> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
-
由 Minchan Kim 提交于
zs_get_total_size_bytes returns a amount of memory zsmalloc consumed with *byte unit* but zsmalloc operates *page unit* rather than byte unit so let's change the API so benefit we could get is that reduce unnecessary overhead (ie, change page unit with byte unit) in zsmalloc. Since return type is pages, "zs_get_total_pages" is better than "zs_get_total_size_bytes". Signed-off-by: NMinchan Kim <minchan@kernel.org> Reviewed-by: NDan Streetman <ddstreet@ieee.org> Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: Jerome Marchand <jmarchan@redhat.com> Cc: <juno.choi@lge.com> Cc: <seungho1.park@lge.com> Cc: Luigi Semenzato <semenzato@google.com> Cc: Nitin Gupta <ngupta@vflare.org> Cc: Seth Jennings <sjennings@variantweb.net> Cc: David Horner <ds2horner@gmail.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
-
- 05 10月, 2014 1 次提交
-
-
由 Mike Snitzer 提交于
Clear QUEUE_FLAG_ADD_RANDOM in all block drivers that set QUEUE_FLAG_NONROT. Historically, all block devices have automatically made entropy contributions. But as previously stated in commit e2e1a148 ("block: add sysfs knob for turning off disk entropy contributions"): - On SSD disks, the completion times aren't as random as they are for rotational drives. So it's questionable whether they should contribute to the random pool in the first place. - Calling add_disk_randomness() has a lot of overhead. There are more reliable sources for randomness than non-rotational block devices. From a security perspective it is better to err on the side of caution than to allow entropy contributions from unreliable "random" sources. Signed-off-by: NMike Snitzer <snitzer@redhat.com> Signed-off-by: NJens Axboe <axboe@fb.com>
-
- 30 8月, 2014 1 次提交
-
-
由 Chao Yu 提交于
Since we allocate a temporary buffer in zram_bvec_read to handle partial page operations in commit 924bd88d ("Staging: zram: allow partial page operations"), our ->failed_reads value may be incorrect as we do not increase its value when failing to allocate the temporary buffer. Let's fix this issue and correct the annotation of failed_reads. Signed-off-by: NChao Yu <chao2.yu@samsung.com> Acked-by: NMinchan Kim <minchan@kernel.org> Cc: Nitin Gupta <ngupta@vflare.org> Acked-by: NJerome Marchand <jmarchan@redhat.com> Acked-by: NSergey Senozhatsky <sergey.senozhatsky@gmail.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
-
- 07 8月, 2014 2 次提交
-
-
由 Weijie Yang 提交于
Currently, we use a rwlock tb_lock to protect concurrent access to the whole zram meta table. However, according to the actual access model, there is only a small chance for upper user to access the same table[index], so the current lock granularity is too big. The idea of optimization is to change the lock granularity from whole meta table to per table entry (table -> table[index]), so that we can protect concurrent access to the same table[index], meanwhile allow the maximum concurrency. With this in mind, several kinds of locks which could be used as a per-entry lock were tested and compared: Test environment: x86-64 Intel Core2 Q8400, system memory 4GB, Ubuntu 12.04, kernel v3.15.0-rc3 as base, zram with 4 max_comp_streams LZO. iozone test: iozone -t 4 -R -r 16K -s 200M -I +Z (1GB zram with ext4 filesystem, take the average of 10 tests, KB/s) Test base CAS spinlock rwlock bit_spinlock ------------------------------------------------------------------- Initial write 1381094 1425435 1422860 1423075 1421521 Rewrite 1529479 1641199 1668762 1672855 1654910 Read 8468009 11324979 11305569 11117273 10997202 Re-read 8467476 11260914 11248059 11145336 10906486 Reverse Read 6821393 8106334 8282174 8279195 8109186 Stride read 7191093 8994306 9153982 8961224 9004434 Random read 7156353 8957932 9167098 8980465 8940476 Mixed workload 4172747 5680814 5927825 5489578 5972253 Random write 1483044 1605588 1594329 1600453 1596010 Pwrite 1276644 1303108 1311612 1314228 1300960 Pread 4324337 4632869 4618386 4457870 4500166 To enhance the possibility of access the same table[index] concurrently, set zram a small disksize(10MB) and let threads run with large loop count. fio test: fio --bs=32k --randrepeat=1 --randseed=100 --refill_buffers --scramble_buffers=1 --direct=1 --loops=3000 --numjobs=4 --filename=/dev/zram0 --name=seq-write --rw=write --stonewall --name=seq-read --rw=read --stonewall --name=seq-readwrite --rw=rw --stonewall --name=rand-readwrite --rw=randrw --stonewall (10MB zram raw block device, take the average of 10 tests, KB/s) Test base CAS spinlock rwlock bit_spinlock ------------------------------------------------------------- seq-write 933789 999357 1003298 995961 1001958 seq-read 5634130 6577930 6380861 6243912 6230006 seq-rw 1405687 1638117 1640256 1633903 1634459 rand-rw 1386119 1614664 1617211 1609267 1612471 All the optimization methods show a higher performance than the base, however, it is hard to say which method is the most appropriate. On the other hand, zram is mostly used on small embedded system, so we don't want to increase any memory footprint. This patch pick the bit_spinlock method, pack object size and page_flag into an unsigned long table.value, so as to not increase any memory overhead on both 32-bit and 64-bit system. On the third hand, even though different kinds of locks have different performances, we can ignore this difference, because: if zram is used as zram swapfile, the swap subsystem can prevent concurrent access to the same swapslot; if zram is used as zram-blk for set up filesystem on it, the upper filesystem and the page cache also prevent concurrent access of the same block mostly. So we can ignore the different performances among locks. Acked-by: NSergey Senozhatsky <sergey.senozhatsky@gmail.com> Reviewed-by: NDavidlohr Bueso <davidlohr@hp.com> Signed-off-by: NWeijie Yang <weijie.yang@samsung.com> Signed-off-by: NMinchan Kim <minchan@kernel.org> Cc: Jerome Marchand <jmarchan@redhat.com> Cc: Nitin Gupta <ngupta@vflare.org> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
-
由 Minchan Kim 提交于
Some architectures (eg, hexagon and PowerPC) could use PAGE_SHIFT of 16 or more. In these cases u16 is not sufficiently large to represent a compressed page's size so use size_t. Signed-off-by: NMinchan Kim <minchan@kernel.org> Reported-by: NWeijie Yang <weijie.yang@samsung.com> Acked-by: NSergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: Jerome Marchand <jmarchan@redhat.com> Cc: Nitin Gupta <ngupta@vflare.org> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
-
- 24 7月, 2014 1 次提交
-
-
由 Minchan Kim 提交于
Sasha reported lockdep warning [1] introduced by [2]. It could be fixed by doing disk revalidation out of the init_lock. It's okay because disk capacity change is protected by init_lock so that revalidate_disk always sees up-to-date value so there is no race. [1] https://lkml.org/lkml/2014/7/3/735 [2] zram: revalidate disk after capacity change Fixes 2e32baea ("zram: revalidate disk after capacity change"). Signed-off-by: NMinchan Kim <minchan@kernel.org> Reported-by: NSasha Levin <sasha.levin@oracle.com> Cc: "Alexander E. Patrakov" <patrakov@gmail.com> Cc: Nitin Gupta <ngupta@vflare.org> Cc: Jerome Marchand <jmarchan@redhat.com> Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> CC: <stable@vger.kernel.org> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
-
- 04 7月, 2014 1 次提交
-
-
由 Minchan Kim 提交于
Alexander reported mkswap on /dev/zram0 is failed if other process is opening the block device file. Step is as follows, 0. Reset the unused zram device. 1. Use a program that opens /dev/zram0 with O_RDWR and sleeps until killed. 2. While that program sleeps, echo the correct value to /sys/block/zram0/disksize. 3. Verify (e.g. in /proc/partitions) that the disk size is applied correctly. It is. 4. While that program still sleeps, attempt to mkswap /dev/zram0. This fails: mkswap: error: swap area needs to be at least 40 KiB When I investigated, the size get by ioctl(fd, BLKGETSIZE64, xxx) on mkswap to get a size of blockdev was zero although zram0 has right size by 2. The reason is zram didn't revalidate disk after changing capacity so that size of blockdev's inode is not uptodate until all of file is close. This patch should fix the BUG. Signed-off-by: NMinchan Kim <minchan@kernel.org> Reported-by: NAlexander E. Patrakov <patrakov@gmail.com> Tested-by: NAlexander E. Patrakov <patrakov@gmail.com> Reviewed-by: NSergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: Nitin Gupta <ngupta@vflare.org> Acked-by: NJerome Marchand <jmarchan@redhat.com> Cc: <stable@vger.kernel.org> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
-
- 05 6月, 2014 1 次提交
-
-
由 Weijie Yang 提交于
We want to skip the physical block(PAGE_SIZE) which is partially covered by the discard bio, so we check the remaining size and subtract it if there is a need to goto the next physical block. The current offset usage in zram_bio_discard is incorrect, it will cause its upper filesystem breakdown. Consider the following scenario: On some architecture or config, PAGE_SIZE is 64K for example, filesystem is set up on zram disk without PAGE_SIZE aligned, a discard bio leads to a offset = 4K and size=72K, normally, it should not really discard any physical block as it partially cover two physical blocks. However, with the current offset usage, it will discard the second physical block and free its memory, which will cause filesystem breakdown. This patch corrects the offset usage in zram_bio_discard. Signed-off-by: NWeijie Yang <weijie.yang@samsung.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Nitin Gupta <ngupta@vflare.org> Acked-by: NJoonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: Bob Liu <bob.liu@oracle.com> Cc: <stable@vger.kernel.org> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
-
- 08 4月, 2014 5 次提交
-
-
由 Joonsoo Kim 提交于
zram is ram based block device and can be used by backend of filesystem. When filesystem deletes a file, it normally doesn't do anything on data block of that file. It just marks on metadata of that file. This behavior has no problem on disk based block device, but has problems on ram based block device, since we can't free memory used for data block. To overcome this disadvantage, there is REQ_DISCARD functionality. If block device support REQ_DISCARD and filesystem is mounted with discard option, filesystem sends REQ_DISCARD to block device whenever some data blocks are discarded. All we have to do is to handle this request. This patch implements to flag up QUEUE_FLAG_DISCARD and handle this REQ_DISCARD request. With it, we can free memory used by zram if it isn't used. [akpm@linux-foundation.org: tweak comments] Signed-off-by: NJoonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Nitin Gupta <ngupta@vflare.org> Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: Jerome Marchand <jmarchan@redhat.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
-
由 Sergey Senozhatsky 提交于
sysfs.txt documentation lists the following requirements: - The buffer will always be PAGE_SIZE bytes in length. On i386, this is 4096. - show() methods should return the number of bytes printed into the buffer. This is the return value of scnprintf(). - show() should always use scnprintf(). Use scnprintf() in show() functions. Signed-off-by: NSergey Senozhatsky <sergey.senozhatsky@gmail.com> Acked-by: NMinchan Kim <minchan@kernel.org> Cc: Jerome Marchand <jmarchan@redhat.com> Cc: Nitin Gupta <ngupta@vflare.org> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
-
由 Minchan Kim 提交于
When we initialized zcomp with single, we couldn't change max_comp_streams without zram reset but current interface doesn't show any error to user and even it changes max_comp_streams's value without any effect so it would make user very confusing. This patch prevents max_comp_streams's change when zcomp was initialized as single zcomp and emit the error to user(ex, echo). [akpm@linux-foundation.org: don't return with the lock held, per Sergey] [fengguang.wu@intel.com: fix coccinelle warnings] Signed-off-by: NMinchan Kim <minchan@kernel.org> Cc: Nitin Gupta <ngupta@vflare.org> Cc: Jerome Marchand <jmarchan@redhat.com> Acked-by: NSergey Senozhatsky <sergey.senozhatsky@gmail.com> Signed-off-by: NFengguang Wu <fengguang.wu@intel.com> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
-
由 Sergey Senozhatsky 提交于
Instead of returning just NULL, return ERR_PTR from zcomp_create() if compressing backend creation has failed. ERR_PTR(-EINVAL) for unsupported compression algorithm request, ERR_PTR(-ENOMEM) for allocation (zcomp or compression stream) error. Perform IS_ERR() check of returned from zcomp_create() value in disksize_store() and set return code to PTR_ERR(). Change suggested by Jerome Marchand. [akpm@linux-foundation.org: clean up error recovery flow] Signed-off-by: NSergey Senozhatsky <sergey.senozhatsky@gmail.com> Reported-by: NJerome Marchand <jmarchan@redhat.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Nitin Gupta <ngupta@vflare.org> Cc: Arnd Bergmann <arnd@arndb.de> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
-
由 Sergey Senozhatsky 提交于
While fixing lockdep spew of ->init_lock reported by Sasha Levin [1], Minchan Kim noted [2] that it's better to move compression backend allocation (using GPF_KERNEL) out of the ->init_lock lock, same way as with zram_meta_alloc(), in order to prevent the same lockdep spew. [1] https://lkml.org/lkml/2014/2/27/337 [2] https://lkml.org/lkml/2014/3/3/32Signed-off-by: NSergey Senozhatsky <sergey.senozhatsky@gmail.com> Reported-by: NMinchan Kim <minchan@kernel.org> Acked-by: NMinchan Kim <minchan@kernel.org> Cc: Sasha Levin <sasha.levin@oracle.com> Acked-by: NJerome Marchand <jmarchan@redhat.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
-