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* mm: compaction: add trace events for memory compaction activityMel Gorman2011-01-13
| | | | | | | | | | | | | | | | | In preparation for a patches promoting the use of memory compaction over lumpy reclaim, this patch adds trace points for memory compaction activity. Using them, we can monitor the scanning activity of the migration and free page scanners as well as the number and success rates of pages passed to page migration. Signed-off-by: Mel Gorman <mel@csn.ul.ie> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Rik van Riel <riel@redhat.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Andy Whitcroft <apw@shadowen.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: smaps: export mlock informationNikanth Karthikesan2011-01-13
| | | | | | | | | | | | | | Currently there is no way to find whether a process has locked its pages in memory or not. And which of the memory regions are locked in memory. Add a new field "Locked" to export this information via the smaps file. Signed-off-by: Nikanth Karthikesan <knikanth@suse.de> Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com> Acked-by: Wu Fengguang <fengguang.wu@intel.com> Cc: Matt Mackall <mpm@selenic.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: convert sprintf_symbol to %pSJoe Perches2011-01-13
| | | | | | | | Signed-off-by: Joe Perches <joe@perches.com> Acked-by: Pekka Enberg <penberg@kernel.org> Cc: Jiri Kosina <trivial@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* fs/mpage.c: consolidate codeHai Shan2011-01-13
| | | | | | | | | | Merge mpage_end_io_read() and mpage_end_io_write() into mpage_end_io() to eliminate code duplication. [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Hai Shan <shan.hai@windriver.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: find_get_pages_contig fixletNick Piggin2011-01-13
| | | | | | | | | | | Testing ->mapping and ->index without a ref is not stable as the page may have been reused at this point. Signed-off-by: Nick Piggin <npiggin@kernel.dk> Reviewed-by: Wu Fengguang <fengguang.wu@intel.com> Reviewed-by: Minchan Kim <minchan.kim@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* vmscan: factor out kswapd sleeping logic from kswapd()KOSAKI Motohiro2011-01-13
| | | | | | | | | | Currently, kswapd() has deep nesting and is slightly hard to read. Clean this up. Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Mel Gorman <mel@csn.ul.ie> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm/page-writeback.c: fix __set_page_dirty_no_writeback() return valueBob Liu2011-01-13
| | | | | | | | | | | __set_page_dirty_no_writeback() should return true if it actually transitioned the page from a clean to dirty state although it seems nobody uses its return value at present. Signed-off-by: Bob Liu <lliubbo@gmail.com> Acked-by: Wu Fengguang <fengguang.wu@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* sync_inode_metadata: fix commentAndrew Morton2011-01-13
| | | | | | | | Use correct function name, remove incorrect apostrophe Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* writeback: avoid livelocking WB_SYNC_ALL writebackJan Kara2011-01-13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When wb_writeback() is called in WB_SYNC_ALL mode, work->nr_to_write is usually set to LONG_MAX. The logic in wb_writeback() then calls __writeback_inodes_sb() with nr_to_write == MAX_WRITEBACK_PAGES and we easily end up with non-positive nr_to_write after the function returns, if the inode has more than MAX_WRITEBACK_PAGES dirty pages at the moment. When nr_to_write is <= 0 wb_writeback() decides we need another round of writeback but this is wrong in some cases! For example when a single large file is continuously dirtied, we would never finish syncing it because each pass would be able to write MAX_WRITEBACK_PAGES and inode dirty timestamp never gets updated (as inode is never completely clean). Thus __writeback_inodes_sb() would write the redirtied inode again and again. Fix the issue by setting nr_to_write to LONG_MAX in WB_SYNC_ALL mode. We do not need nr_to_write in WB_SYNC_ALL mode anyway since write_cache_pages() does livelock avoidance using page tagging in WB_SYNC_ALL mode. This makes wb_writeback() call __writeback_inodes_sb() only once on WB_SYNC_ALL. The latter function won't livelock because it works on - a finite set of files by doing queue_io() once at the beginning - a finite set of pages by PAGECACHE_TAG_TOWRITE page tagging After this patch, program from http://lkml.org/lkml/2010/10/24/154 is no longer able to stall sync forever. [fengguang.wu@intel.com: fix locking comment] Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Wu Fengguang <fengguang.wu@intel.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Dave Chinner <david@fromorbit.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Jan Engelhardt <jengelh@medozas.de> Cc: Jens Axboe <axboe@kernel.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* writeback: stop background/kupdate works from livelocking other worksJan Kara2011-01-13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Background writeback is easily livelockable in a loop in wb_writeback() by a process continuously re-dirtying pages (or continuously appending to a file). This is in fact intended as the target of background writeback is to write dirty pages it can find as long as we are over dirty_background_threshold. But the above behavior gets inconvenient at times because no other work queued in the flusher thread's queue gets processed. In particular, since e.g. sync(1) relies on flusher thread to do all the IO for it, sync(1) can hang forever waiting for flusher thread to do the work. Generally, when a flusher thread has some work queued, someone submitted the work to achieve a goal more specific than what background writeback does. Moreover by working on the specific work, we also reduce amount of dirty pages which is exactly the target of background writeout. So it makes sense to give specific work a priority over a generic page cleaning. Thus we interrupt background writeback if there is some other work to do. We return to the background writeback after completing all the queued work. This may delay the writeback of expired inodes for a while, however the expired inodes will eventually be flushed to disk as long as the other works won't livelock. [fengguang.wu@intel.com: update comment] Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Wu Fengguang <fengguang.wu@intel.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Dave Chinner <david@fromorbit.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Jan Engelhardt <jengelh@medozas.de> Cc: Jens Axboe <axboe@kernel.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* writeback: trace wakeup event for background writebackWu Fengguang2011-01-13
| | | | | | | | | | | | | | | This tracks when balance_dirty_pages() tries to wakeup the flusher thread for background writeback (if it was not started already). Suggested-by: Christoph Hellwig <hch@infradead.org> Signed-off-by: Wu Fengguang <fengguang.wu@intel.com> Cc: Jan Kara <jack@suse.cz> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Dave Chinner <david@fromorbit.com> Cc: Jan Engelhardt <jengelh@medozas.de> Cc: Jens Axboe <axboe@kernel.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* writeback: integrated background writeback workJan Kara2011-01-13
| | | | | | | | | | | | | | | | | | | | | | | | | | Check whether background writeback is needed after finishing each work. When bdi flusher thread finishes doing some work check whether any kind of background writeback needs to be done (either because dirty_background_ratio is exceeded or because we need to start flushing old inodes). If so, just do background write back. This way, bdi_start_background_writeback() just needs to wake up the flusher thread. It will do background writeback as soon as there is no other work. This is a preparatory patch for the next patch which stops background writeback as soon as there is other work to do. Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Wu Fengguang <fengguang.wu@intel.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Dave Chinner <david@fromorbit.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Jan Engelhardt <jengelh@medozas.de> Cc: Jens Axboe <axboe@kernel.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: vmstat: use a single setter function and callback for adjusting percpu ↵Mel Gorman2011-01-13
| | | | | | | | | | | | | | | | | | | thresholds reduce_pgdat_percpu_threshold() and restore_pgdat_percpu_threshold() exist to adjust the per-cpu vmstat thresholds while kswapd is awake to avoid errors due to counter drift. The functions duplicate some code so this patch replaces them with a single set_pgdat_percpu_threshold() that takes a callback function to calculate the desired threshold as a parameter. [akpm@linux-foundation.org: readability tweak] [kosaki.motohiro@jp.fujitsu.com: set_pgdat_percpu_threshold(): don't use for_each_online_cpu] Signed-off-by: Mel Gorman <mel@csn.ul.ie> Reviewed-by: Christoph Lameter <cl@linux.com> Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: page allocator: adjust the per-cpu counter threshold when memory is lowMel Gorman2011-01-13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit aa45484 ("calculate a better estimate of NR_FREE_PAGES when memory is low") noted that watermarks were based on the vmstat NR_FREE_PAGES. To avoid synchronization overhead, these counters are maintained on a per-cpu basis and drained both periodically and when a threshold is above a threshold. On large CPU systems, the difference between the estimate and real value of NR_FREE_PAGES can be very high. The system can get into a case where pages are allocated far below the min watermark potentially causing livelock issues. The commit solved the problem by taking a better reading of NR_FREE_PAGES when memory was low. Unfortately, as reported by Shaohua Li this accurate reading can consume a large amount of CPU time on systems with many sockets due to cache line bouncing. This patch takes a different approach. For large machines where counter drift might be unsafe and while kswapd is awake, the per-cpu thresholds for the target pgdat are reduced to limit the level of drift to what should be a safe level. This incurs a performance penalty in heavy memory pressure by a factor that depends on the workload and the machine but the machine should function correctly without accidentally exhausting all memory on a node. There is an additional cost when kswapd wakes and sleeps but the event is not expected to be frequent - in Shaohua's test case, there was one recorded sleep and wake event at least. To ensure that kswapd wakes up, a safe version of zone_watermark_ok() is introduced that takes a more accurate reading of NR_FREE_PAGES when called from wakeup_kswapd, when deciding whether it is really safe to go back to sleep in sleeping_prematurely() and when deciding if a zone is really balanced or not in balance_pgdat(). We are still using an expensive function but limiting how often it is called. When the test case is reproduced, the time spent in the watermark functions is reduced. The following report is on the percentage of time spent cumulatively spent in the functions zone_nr_free_pages(), zone_watermark_ok(), __zone_watermark_ok(), zone_watermark_ok_safe(), zone_page_state_snapshot(), zone_page_state(). vanilla 11.6615% disable-threshold 0.2584% David said: : We had to pull aa454840 "mm: page allocator: calculate a better estimate : of NR_FREE_PAGES when memory is low and kswapd is awake" from 2.6.36 : internally because tests showed that it would cause the machine to stall : as the result of heavy kswapd activity. I merged it back with this fix as : it is pending in the -mm tree and it solves the issue we were seeing, so I : definitely think this should be pushed to -stable (and I would seriously : consider it for 2.6.37 inclusion even at this late date). Signed-off-by: Mel Gorman <mel@csn.ul.ie> Reported-by: Shaohua Li <shaohua.li@intel.com> Reviewed-by: Christoph Lameter <cl@linux.com> Tested-by: Nicolas Bareil <nico@chdir.org> Cc: David Rientjes <rientjes@google.com> Cc: Kyle McMartin <kyle@mcmartin.ca> Cc: <stable@kernel.org> [2.6.37.1, 2.6.36.x] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* sched: remove long deprecated CLONE_STOPPED flagDave Jones2011-01-13
| | | | | | | | | | | | | This warning was added in commit bdff746a3915 ("clone: prepare to recycle CLONE_STOPPED") three years ago. 2.6.26 came and went. As far as I know, no-one is actually using CLONE_STOPPED. Signed-off-by: Dave Jones <davej@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@elte.hu> Cc: Tejun Heo <tj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* atmel_serial: fix RTS high after initialization in RS485 modeClaudio Scordino2011-01-13
| | | | | | | | | | | | | | | When working in RS485 mode, the atmel_serial driver keeps RTS high after the initialization of the serial port. It goes low only after the first character has been sent. [akpm@linux-foundation.org: simplify code] Signed-off-by: Claudio Scordino <claudio@evidence.eu.com> Signed-off-by: Arkadiusz Bubala <arkadiusz.bubala@gmail.com> Tested-by: Arkadiusz Bubala <arkadiusz.bubala@gmail.com> Cc: Nicolas Ferre <nicolas.ferre@atmel.com> Cc: Greg KH <greg@kroah.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* irq: use per_cpu kstat_irqsEric Dumazet2011-01-13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | Use modern per_cpu API to increment {soft|hard}irq counters, and use per_cpu allocation for (struct irq_desc)->kstats_irq instead of an array. This gives better SMP/NUMA locality and saves few instructions per irq. With small nr_cpuids values (8 for example), kstats_irq was a small array (less than L1_CACHE_BYTES), potentially source of false sharing. In the !CONFIG_SPARSE_IRQ case, remove the huge, NUMA/cache unfriendly kstat_irqs_all[NR_IRQS][NR_CPUS] array. Note: we still populate kstats_irq for all possible irqs in early_irq_init(). We probably could use on-demand allocations. (Code included in alloc_descs()). Problem is not all IRQS are used with a prior alloc_descs() call. kstat_irqs_this_cpu() is not used anymore, remove it. Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Reviewed-by: Christoph Lameter <cl@linux.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Andi Kleen <andi@firstfloor.org> Cc: Tejun Heo <tj@kernel.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>
* MAINTAINERS: update entries affecting VIA TechnologiesBruce Chang2011-01-13
| | | | | | | | | | | | | | | Since the original maintainer-Joseph Chan (josephchan@via.com.tw) doesn't handle the Linux driver for VIA now, I would like to request to update the maintainer for the SD/MMC CARD CONTROLLER DRIVER and VIA UNICHROME(PRO)/CHROME9 FRAMEBUFFER DRIVER before we find a better one. Signed-off-by: Bruce Chang <brucechang@via.com.tw> Signed-off-by: Florian Tobias Schandinat <FlorianSchandinat@gmx.de> Cc: Joseph Chan <JosephChan@via.com.tw> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Harald Welte <HaraldWelte@viatech.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge git://git.kernel.org/pub/scm/linux/kernel/git/agk/linux-2.6-dmLinus Torvalds2011-01-13
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * git://git.kernel.org/pub/scm/linux/kernel/git/agk/linux-2.6-dm: (32 commits) dm: raid456 basic support dm: per target unplug callback support dm: introduce target callbacks and congestion callback dm mpath: delay activate_path retry on SCSI_DH_RETRY dm: remove superfluous irq disablement in dm_request_fn dm log: use PTR_ERR value instead of ENOMEM dm snapshot: avoid storing private suspended state dm snapshot: persistent make metadata_wq multithreaded dm: use non reentrant workqueues if equivalent dm: convert workqueues to alloc_ordered dm stripe: switch from local workqueue to system_wq dm: dont use flush_scheduled_work dm snapshot: remove unused dm_snapshot queued_bios_work dm ioctl: suppress needless warning messages dm crypt: add loop aes iv generator dm crypt: add multi key capability dm crypt: add post iv call to iv generator dm crypt: use io thread for reads only if mempool exhausted dm crypt: scale to multiple cpus dm crypt: simplify compatible table output ...
| * dm: raid456 basic supportNeilBrown2011-01-13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch is the skeleton for the DM target that will be the bridge from DM to MD (initially RAID456 and later RAID1). It provides a way to use device-mapper interfaces to the MD RAID456 drivers. As with all device-mapper targets, the nominal public interfaces are the constructor (CTR) tables and the status outputs (both STATUSTYPE_INFO and STATUSTYPE_TABLE). The CTR table looks like the following: 1: <s> <l> raid \ 2: <raid_type> <#raid_params> <raid_params> \ 3: <#raid_devs> <meta_dev1> <dev1> .. <meta_devN> <devN> Line 1 contains the standard first three arguments to any device-mapper target - the start, length, and target type fields. The target type in this case is "raid". Line 2 contains the arguments that define the particular raid type/personality/level, the required arguments for that raid type, and any optional arguments. Possible raid types include: raid4, raid5_la, raid5_ls, raid5_rs, raid6_zr, raid6_nr, and raid6_nc. (again, raid1 is planned for the future.) The list of required and optional parameters is the same for all the current raid types. The required parameters are positional, while the optional parameters are given as key/value pairs. The possible parameters are as follows: <chunk_size> Chunk size in sectors. [[no]sync] Force/Prevent RAID initialization [rebuild <idx>] Rebuild the drive indicated by the index [daemon_sleep <ms>] Time between bitmap daemon work to clear bits [min_recovery_rate <kB/sec/disk>] Throttle RAID initialization [max_recovery_rate <kB/sec/disk>] Throttle RAID initialization [max_write_behind <value>] See '-write-behind=' (man mdadm) [stripe_cache <sectors>] Stripe cache size for higher RAIDs Line 3 contains the list of devices that compose the array in metadata/data device pairs. If the metadata is stored separately, a '-' is given for the metadata device position. If a drive has failed or is missing at creation time, a '-' can be given for both the metadata and data drives for a given position. Examples: # RAID4 - 4 data drives, 1 parity # No metadata devices specified to hold superblock/bitmap info # Chunk size of 1MiB # (Lines separated for easy reading) 0 1960893648 raid \ raid4 1 2048 \ 5 - 8:17 - 8:33 - 8:49 - 8:65 - 8:81 # RAID4 - 4 data drives, 1 parity (no metadata devices) # Chunk size of 1MiB, force RAID initialization, # min recovery rate at 20 kiB/sec/disk 0 1960893648 raid \ raid4 4 2048 min_recovery_rate 20 sync\ 5 - 8:17 - 8:33 - 8:49 - 8:65 - 8:81 Performing a 'dmsetup table' should display the CTR table used to construct the mapping (with possible reordering of optional parameters). Performing a 'dmsetup status' will yield information on the state and health of the array. The output is as follows: 1: <s> <l> raid \ 2: <raid_type> <#devices> <1 health char for each dev> <resync_ratio> Line 1 is standard DM output. Line 2 is best shown by example: 0 1960893648 raid raid4 5 AAAAA 2/490221568 Here we can see the RAID type is raid4, there are 5 devices - all of which are 'A'live, and the array is 2/490221568 complete with recovery. Cc: linux-raid@vger.kernel.org Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
| * dm: per target unplug callback supportNeilBrown2011-01-13
| | | | | | | | | | | | | | | | | | | | Add per-target unplug callback support. Cc: linux-raid@vger.kernel.org Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
| * dm: introduce target callbacks and congestion callbackNeilBrown2011-01-13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | DM currently implements congestion checking by checking on congestion in each component device. For raid456 we need to also check if the stripe cache is congested. Add per-target congestion checker callback support. Extending the target_callbacks structure with additional callback functions allows for establishing multiple callbacks per-target (a callback is also needed for unplug). Cc: linux-raid@vger.kernel.org Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
| * dm mpath: delay activate_path retry on SCSI_DH_RETRYChandra Seetharaman2011-01-13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch adds a user-configurable 'pg_init_delay_msecs' feature. Use this feature to specify the number of milliseconds to delay before retrying scsi_dh_activate, when SCSI_DH_RETRY is returned. SCSI Device Handlers return SCSI_DH_IMM_RETRY if we could retry activation immediately and SCSI_DH_RETRY in cases where it is better to retry after some delay. Currently we immediately retry scsi_dh_activate irrespective of SCSI_DH_IMM_RETRY and SCSI_DH_RETRY. The 'pg_init_delay_msecs' feature may be provided during table create or load, e.g.: dmsetup create --table "0 20971520 multipath 3 queue_if_no_path \ pg_init_delay_msecs 2500 ..." mpatha The default for 'pg_init_delay_msecs' is 2000 milliseconds. Maximum configurable delay is 60000 milliseconds. Specifying a 'pg_init_delay_msecs' of 0 will cause immediate retry. Signed-off-by: Nikanth Karthikesan <knikanth@suse.de> Signed-off-by: Chandra Seetharaman <sekharan@us.ibm.com> Acked-by: Mike Christie <michaelc@cs.wisc.edu> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
| * dm: remove superfluous irq disablement in dm_request_fnKiyoshi Ueda2011-01-13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch changes spin_lock_irq() to spin_lock() in dm_request_fn(). This patch is just a clean-up and no functional change. The spin_lock_irq() was leftover from the early request-based dm code, where map_request() used to enable interrupts. Since current map_request() never enables interrupts, we can change it to spin_lock() to match the prior spin_unlock(). Auditing through the dm and block-layer code called from map_request(), I confirmed all functions save/restore interrupt status, so no function returning with interrupts enabled. Also I haven't observed any problem on my test environment which uses scsi and lpfc driver after heavy I/O testing with occasional path down/up. Added BUG_ON() to detect breakage in future. Signed-off-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com> Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
| * dm log: use PTR_ERR value instead of ENOMEMDan Carpenter2011-01-13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | It's nicer to return the PTR_ERR() value instead of just returning -ENOMEM. In the current code the PTR_ERR() value is always equal to -ENOMEM so this doesn't actually affect anything, but still... In addition, dm_dirty_log_create() doesn't check for a specific -ENOMEM return. So this change is safe relative to potential for a non -ENOMEM return in the future. Signed-off-by: Dan Carpenter <error27@gmail.com> Acked-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
| * dm snapshot: avoid storing private suspended stateMike Snitzer2011-01-13
| | | | | | | | | | | | | | | | Use dm_suspended() rather than having each snapshot target maintain a private 'suspended' flag in struct dm_snapshot. Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
| * dm snapshot: persistent make metadata_wq multithreadedTejun Heo2011-01-13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | metadata_wq serves on-stack work items from chunk_io(). Even if multiple chunk_io() are simultaneously in progress, each is independent and queued only once, so multithreaded workqueue can be safely used. Switch metadata_wq to multithread and flush the work item instead of the workqueue in chunk_io(). Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
| * dm: use non reentrant workqueues if equivalentTejun Heo2011-01-13
| | | | | | | | | | | | | | | | | | | | | | | | kmirrord_wq, kcopyd_work and md->wq are created per dm instance and serve only a single work item from the dm instance, so non-reentrant workqueues would provide the same ordering guarantees as ordered ones while allowing CPU affinity and use of the workqueues for other purposes. Switch them to non-reentrant workqueues. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
| * dm: convert workqueues to alloc_orderedTejun Heo2011-01-13
| | | | | | | | | | | | | | | | | | | | Convert all create[_singlethread]_work() users to the new alloc[_ordered]_workqueue(). This conversion is mechanical and doesn't introduce any behavior change. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
| * dm stripe: switch from local workqueue to system_wqTejun Heo2011-01-13
| | | | | | | | | | | | | | | | | | | | | | | | kstriped only serves sc->kstriped_ws which runs dm_table_event(). This doesn't need to be executed from an ordered workqueue w/ rescuer. Drop kstriped and use the system_wq instead. While at it, rename kstriped_ws to trigger_event so that it's consistent with other dm modules. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
| * dm: dont use flush_scheduled_workTejun Heo2011-01-13
| | | | | | | | | | | | | | | | | | | | flush_scheduled_work() is being deprecated. Flush the used work directly instead. In all dm targets, the only work which uses system_wq is ->trigger_event. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
| * dm snapshot: remove unused dm_snapshot queued_bios_workTejun Heo2011-01-13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | dm_snapshot->queued_bios_work isn't used. Remove ->queued_bios[_work] from dm_snapshot structure, the flush_queued_bios work function and ksnapd workqueue. The DM snapshot changes that were going to use the ksnapd workqueue were either superseded (fix for origin write races) or never completed (deallocation of invalid snapshot's memory via workqueue). Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
| * dm ioctl: suppress needless warning messagesMilan Broz2011-01-13
| | | | | | | | | | | | | | | | | | | | | | | | The device-mapper should not send warning messages to syslog if a device is not found. This can be done by userspace according to the returned dm-ioctl error code. So move these messages to debug level and use rate limiting to not flood syslog. Signed-off-by: Milan Broz <mbroz@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
| * dm crypt: add loop aes iv generatorMilan Broz2011-01-13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch adds a compatible implementation of the block chaining mode used by the Loop-AES block device encryption system (http://loop-aes.sourceforge.net/) designed by Jari Ruusu. It operates on full 512 byte sectors and uses CBC with an IV derived from the sector number, the data and optionally extra IV seed. This means that after CBC decryption the first block of sector must be tweaked according to decrypted data. Loop-AES can use three encryption schemes: version 1: is plain aes-cbc mode (already compatible) version 2: uses 64 multikey scheme with own IV generator version 3: the same as version 2 with additional IV seed (it uses 65 keys, last key is used as IV seed) The IV generator is here named lmk (Loop-AES multikey) and for the cipher specification looks like: aes:64-cbc-lmk Version 2 and 3 is recognised according to length of provided multi-key string (which is just hexa encoded "raw key" used in original Loop-AES ioctl). Configuration of the device and decoding key string will be done in userspace (cryptsetup). (Loop-AES stores keys in gpg encrypted file, raw keys are output of simple hashing of lines in this file). Based on an implementation by Max Vozeler: http://article.gmane.org/gmane.linux.kernel.cryptoapi/3752/ Signed-off-by: Milan Broz <mbroz@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com> CC: Max Vozeler <max@hinterhof.net>
| * dm crypt: add multi key capabilityMilan Broz2011-01-13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch adds generic multikey handling to be used in following patch for Loop-AES mode compatibility. This patch extends mapping table to optional keycount and implements generic multi-key capability. With more keys defined the <key> string is divided into several <keycount> sections and these are used for tfms. The tfm is used according to sector offset (sector 0->tfm[0], sector 1->tfm[1], sector N->tfm[N modulo keycount]) (only power of two values supported for keycount here). Because of tfms per-cpu allocation, this mode can be take a lot of memory on large smp systems. Signed-off-by: Milan Broz <mbroz@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com> Cc: Max Vozeler <max@hinterhof.net>
| * dm crypt: add post iv call to iv generatorMilan Broz2011-01-13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | IV (initialisation vector) can in principle depend not only on sector but also on plaintext data (or other attributes). Change IV generator interface to work directly with dmreq structure to allow such dependence in generator. Also add post() function which is called after the crypto operation. This allows tricky modification of decrypted data or IV internals. In asynchronous mode the post() can be called after ctx->sector count was increased so it is needed to add iv_sector copy directly to dmreq structure. (N.B. dmreq always include only one sector in scatterlists) Signed-off-by: Milan Broz <mbroz@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
| * dm crypt: use io thread for reads only if mempool exhaustedMilan Broz2011-01-13
| | | | | | | | | | | | | | | | | | | | | | If there is enough memory, code can directly submit bio instead queing this operation in separate thread. Try to alloc bio clone with GFP_NOWAIT and only if it fails use separate queue (map function cannot block here). Signed-off-by: Milan Broz <mbroz@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
| * dm crypt: scale to multiple cpusAndi Kleen2011-01-13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently dm-crypt does all the encryption work for a single dm-crypt mapping in a single workqueue. This does not scale well when multiple CPUs are submitting IO at a high rate. The single CPU running the single thread cannot keep up with the encryption and encrypted IO performance tanks. This patch changes the crypto workqueue to be per CPU. This means that as long as the IO submitter (or the interrupt target CPUs for reads) runs on different CPUs the encryption work will be also parallel. To avoid a bottleneck on the IO worker I also changed those to be per-CPU threads. There is still some shared data, so I suspect some bouncing cache lines. But I haven't done a detailed study on that yet. Signed-off-by: Andi Kleen <ak@linux.intel.com> Signed-off-by: Milan Broz <mbroz@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
| * dm crypt: simplify compatible table outputMilan Broz2011-01-13
| | | | | | | | | | | | | | | | Rename cc->cipher_mode to cc->cipher_string and store the whole of the cipher information so it can easily be printed when processing the DM_DEV_STATUS ioctl. Signed-off-by: Milan Broz <mbroz@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
| * dm log userspace: add version number to commsJonathan Brassow2011-01-13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch adds a 'version' field to the 'dm_ulog_request' structure. The 'version' field is taken from a portion of the unused 'padding' field in the 'dm_ulog_request' structure. This was done to avoid changing the size of the structure and possibly disrupting backwards compatibility. The version number will help notify user-space daemons when a change has been made to the kernel/userspace log API. Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
| * dm log userspace: group clear and mark requestsJonathan Brassow2011-01-13
| | | | | | | | | | | | | | | | | | | | | | Allow the device-mapper log's 'mark' and 'clear' requests to be grouped and processed in a batch. This can significantly reduce the amount of traffic going between the kernel and userspace (where the processing daemon resides). Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
| * dm log userspace: split flush queueJonathan Brassow2011-01-13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Split the 'flush_list', which contained a mix of both 'mark' and 'clear' requests, into two distinct lists ('mark_list' and 'clear_list'). The device mapper log implementations (used by various DM targets) are allowed to cache 'mark' and 'clear' requests until a 'flush' is received. Until now, these cached requests were kept in the same list. They will now be put into distinct lists to facilitate group processing of these requests (in the next patch). Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
| * dm kcopyd: delay unpluggingMikulas Patocka2011-01-13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Make kcopyd merge more I/O requests by using device unplugging. Without this patch, each I/O request is dispatched separately to the device. If the device supports tagged queuing, there are many small requests sent to the device. To improve performance, this patch will batch as many requests as possible, allowing the queue to merge consecutive requests, and send them to the device at once. In my tests (15k SCSI disk), this patch improves sequential write throughput: Sequential write throughput (chunksize of 4k, 32k, 512k) unpatched: 15.2, 18.5, 17.5 MB/s patched: 14.4, 22.6, 23.0 MB/s In most common uses (snapshot or two-way mirror), kcopyd is only used for two devices, one for reading and the other for writing, thus this optimization is implemented only for two devices. The optimization may be extended to n-way mirrors with some code complexity increase. We keep track of two block devices to unplug (one for read and the other for write) and unplug them when exiting "do_work" thread. If there are more devices used (in theory it could happen, in practice it is rare), we unplug immediately. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
| * dm log userspace: trap all failed log construction errorsJonathan Brassow2011-01-13
| | | | | | | | | | | | | | | | | | When constructing a mirror log, it is possible for the initial request to fail for other reasons besides -ESRCH. These must be handled too. Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
| * dm crypt: set key size earlyMilan Broz2011-01-13
| | | | | | | | | | | | | | | | | | | | Simplify key size verification (hexadecimal string) and set key size early in constructor. (Patch required by later changes.) Signed-off-by: Milan Broz <mbroz@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
| * dm: remove dm_mutex after bkl conversionMilan Broz2011-01-13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch replaces dm_mutex with _minor_lock in dm_blk_close() and then removes it. During the BKL conversion, commit 6e9624b8caec290d28b4c6d9ec75749df6372b87 (block: push down BKL into .open and .release) pushed lock_kernel() down into dm_blk_open/close calls. Commit 2a48fc0ab24241755dc93bfd4f01d68efab47f5a (block: autoconvert trivial BKL users to private mutex) converted it to a local mutex, but _minor_lock is sufficient. Signed-off-by: Milan Broz <mbroz@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
| * dm raid1: support discardMike Snitzer2011-01-13
| | | | | | | | | | | | | | | | Enable discard support in the DM mirror target. Also change an existing use of 'bvec' to 'addr' in the union. Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
| * dm ioctl: allow rename to fill empty uuidPeter Jones2011-01-13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Allow the uuid of a mapped device to be set after device creation. Previously the uuid (which is optional) could only be set by DM_DEV_CREATE. If no uuid was supplied it could not be set later. Sometimes it's necessary to create the device before the uuid is known, and in such cases the uuid must be filled in after the creation. This patch extends DM_DEV_RENAME to accept a uuid accompanied by a new flag DM_UUID_FLAG. This can only be done once and if no uuid was previously supplied. It cannot be used to change an existing uuid. DM_VERSION_MINOR is also bumped to 19 to indicate this interface extension is available. Signed-off-by: Peter Jones <pjones@redhat.com> Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
| * dm io: remove BIO_RW_SYNCIO flag from kcopydMikulas Patocka2011-01-13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Remove the REQ_SYNC flag to improve write throughput when writing to the origin with a snapshot on the same device (using the CFQ I/O scheduler). Sequential write throughput (chunksize of 4k, 32k, 512k) unpatched: 8.5, 8.6, 9.3 MB/s patched: 15.2, 18.5, 17.5 MB/s Snapshot exception reallocations are triggered by writes that are usually async, so mark the associated dm_io_request as async as well. This helps when using the CFQ I/O scheduler because it has separate queues for sync and async I/O. Async is optimized for throughput; sync for latency. With this change we're consciously favoring throughput over latency. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
| * dm mpath: disable blk_abort_queueMike Snitzer2011-01-13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Revert commit 224cb3e981f1b2f9f93dbd49eaef505d17d894c2 dm: Call blk_abort_queue on failed paths Multipath began to use blk_abort_queue() to allow for lower latency path deactivation. This was found to cause list corruption: the cmd gets blk_abort_queued/timedout run on it and the scsi eh somehow is able to complete and run scsi_queue_insert while scsi_request_fn is still trying to process the request. https://www.redhat.com/archives/dm-devel/2010-November/msg00085.html Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com> Cc: Mike Anderson <andmike@linux.vnet.ibm.com> Cc: Mike Christie <michaelc@cs.wisc.edu> Cc: stable@kernel.org
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