- 14 Jan, 2011 18 commits
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KOSAKI Motohiro authored
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>
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Bob Liu authored
__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:
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Andrew Morton authored
Use correct function name, remove incorrect apostrophe Cc: Christoph Hellwig <hch@lst.de> Signed-off-by:
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Jan Kara authored
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:
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Jan Kara authored
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:
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Wu Fengguang authored
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:
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Jan Kara authored
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:
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Mel Gorman authored
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:
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Mel Gorman authored
Commit aa454840 ("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:
Shaohua Li <shaohua.li@intel.com> Reviewed-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:
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Dave Jones authored
This warning was added in commit bdff746a ("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:
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Claudio Scordino authored
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:
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Eric Dumazet authored
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:
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Bruce Chang authored
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:
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git://git.kernel.org/pub/scm/linux/kernel/git/agk/linux-2.6-dmLinus Torvalds authored
* 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 ...
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git://neil.brown.name/mdLinus Torvalds authored
* 'for-linus' of git://neil.brown.name/md: md: Fix removal of extra drives when converting RAID6 to RAID5 md: range check slot number when manually adding a spare. md/raid5: handle manually-added spares in start_reshape. md: fix sync_completed reporting for very large drives (>2TB) md: allow suspend_lo and suspend_hi to decrease as well as increase. md: Don't let implementation detail of curr_resync leak out through sysfs. md: separate meta and data devs md-new-param-to_sync_page_io md-new-param-to-calc_dev_sboffset md: Be more careful about clearing flags bit in ->recovery md: md_stop_writes requires mddev_lock. md/raid5: use sysfs_notify_dirent_safe to avoid NULL pointer md: Ensure no IO request to get md device before it is properly initialised. md: Fix single printks with multiple KERN_<level>s md: fix regression resulting in delays in clearing bits in a bitmap md: fix regression with re-adding devices to arrays with no metadata
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git://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux-2.6Linus Torvalds authored
* 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux-2.6: [IA64] fix build error - arch/ia64/kernel/perfmon.c
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Linus Torvalds authored
This reverts commit 0fdae42d, which wasn't really supposed to go in, and causes lots of annoying warnings. Quoth Andrew: "Complete brainfart - I meant to drop that patch ages ago." Quoth Greg: "Ick, yeah, that patch isn't ok to go in as-is, all of the callers need to be fixed up first, which is what I thought we had agreed on..." Reported-by:
Stephen Rothwell <sfr@canb.auug.org.au> Acked-by:
Greg KH <greg@kroah.com> Signed-off-by:
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Linus Torvalds authored
Stephen Rothwell reports that the vfs merge broke the build of ecryptfs. The breakage comes from commit 66cb7666 ("sanitize ecryptfs ->mount()") which was obviously not even build tested. Tssk, tssk, Al. This is the minimal build fixup for the situation, although I don't have a filesystem to actually test it with. Reported-by:
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- 13 Jan, 2011 22 commits
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Tony Luck authored
arch/ia64/kernel/perfmon.c:621: error: duplicate 'static' Introduced by commit c74a1cbb pass default dentry_operations to mount_pseudo() Signed-off-by:
Tony Luck <tony.luck@intel.com>
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NeilBrown authored
When a RAID6 is converted to a RAID5, the extra drive should be discarded. However it isn't due to a typo in a comparison. This bug was introduced in commit e93f68a1 in 2.6.35-rc4 and is suitable for any -stable since than. As the extra drive is not removed, the 'degraded' counter is wrong and so the RAID5 will not respond correctly to a subsequent failure. Cc: stable@kernel.org Signed-off-by:
NeilBrown <neilb@suse.de>
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NeilBrown authored
When adding a spare to an active array, we should check the slot number, but allow it to be larger than raid_disks if a reshape is being prepared. Apply the same test when adding a device to an array-under-construction. It already had most of the test in place, but not quite all. Signed-off-by: -
NeilBrown authored
It is possible to manually add spares to specific slots before starting a reshape. raid5_start_reshape should recognised this possibility and include it in the accounting. Signed-off-by: -
Rémi Rérolle authored
The values exported in the sync_completed file are unsigned long, which overflows with very large drives, resulting in wrong values reported. Since sync_completed uses sectors as unit, we'll start getting wrong values with components larger than 2TB. This patch simply replaces the use of unsigned long by unsigned long long. Signed-off-by:
Rémi Rérolle <rrerolle@lacie.com> Signed-off-by:
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NeilBrown authored
The sysfs attributes 'suspend_lo' and 'suspend_hi' describe a region to which read/writes are suspended so that the under lying data can be manipulated without user-space noticing. Currently the window they describe can only move forwards along the device. However this is an unnecessary restriction which will cause problems with planned developments. So relax this restriction and allow these endpoints to move arbitrarily. Signed-off-by: -
NeilBrown authored
mddev->curr_resync has artificial values of '1' and '2' which are used by the code which ensures only one resync is happening at a time on any given device. These values are internal and should never be exposed to user-space (except when translated appropriately as in the 'pending' status in /proc/mdstat). Unfortunately they are as ->curr_resync is assigned to ->curr_resync_completed and that value is directly visible through sysfs. So change the assignments to ->curr_resync_completed to get the same valued from elsewhere in a form that doesn't have the magic '1' or '2' values. Signed-off-by: -
Jonathan Brassow authored
Allow the metadata to be on a separate device from the data. This doesn't mean the data and metadata will by on separate physical devices - it simply gives device-mapper and userspace tools more flexibility. Signed-off-by: -
Jonathan Brassow authored
Add new parameter to 'sync_page_io'. The new parameter allows us to distinguish between metadata and data operations. This becomes important later when we add the ability to use separate devices for data and metadata. Signed-off-by:Jonathan Brassow <jbrassow@redhat.com>
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Jonathan Brassow authored
When we allow for separate devices for data and metadata in a later patch, we will need to be able to calculate the superblock offset based on more than the bdev. Signed-off-by: -
NeilBrown authored
Setting ->recovery to 0 is generally not a good idea as it could clear bits that shouldn't be cleared. In particular, MD_RECOVERY_FROZEN should only be cleared on explicit request from user-space. So when we need to clear things, just clear the bits that need clearing. As there are a few different places which reap a resync process - and some do an incomplte job - factor out the code for doing the from md_check_recovery and call that function instead of open coding part of it. Signed-off-by:
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NeilBrown authored
As md_stop_writes manipulates the sync_thread and calls md_update_sb, it need to be called with mddev_lock held. In all internal cases it is, but the symbol is exported for dm-raid to call and in that case the lock won't be help. Do make an exported version which takes the lock, and an internal version which does not. Signed-off-by: -
Jonathan Brassow authored
With the module parameter 'start_dirty_degraded' set, raid5_spare_active() previously called sysfs_notify_dirent() with a NULL argument (rdev->sysfs_state) when a rebuild finished. Signed-off-by:
Mike Snitzer <snitzer@redhat.com>
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NeilBrown authored
When an md device is in the process of coming on line it is possible for an IO request (typically a partition table probe) to get through before the array is fully initialised, which can cause unexpected behaviour (e.g. a crash). So explicitly record when the array is ready for IO and don't allow IO through until then. There is no possibility for a similar problem when the array is going off-line as there must only be one 'open' at that time, and it is busy off-lining the array and so cannot send IO requests. So no memory barrier is needed in md_stop() This has been a bug since commit 409c57f3 in 2.6.30 which introduced md_make_request. Before then, each personality would register its own make_request_fn when it was ready. This is suitable for any stable kernel from 2.6.30.y onwards. Cc: <stable@kernel.org> Signed-off-by:
"Hawrylewicz Czarnowski, Przemyslaw" <przemyslaw.hawrylewicz.czarnowski@intel.com>
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Joe Perches authored
Noticed-by:
Russell King <linux@arm.linux.org.uk> Signed-off-by:
Joe Perches <joe@perches.com> Signed-off-by:
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NeilBrown authored
commit 589a594b (2.6.37-rc4) fixed a problem were md_thread would sometimes call the ->run function at a bad time. If an error is detected during array start up after the md_thread has been started, the md_thread is killed. This resulted in the ->run function being called once. However the array may not be in a state that it is safe to call ->run. However the fix imposed meant that ->run was not called on a timeout. This means that when an array goes idle, bitmap bits do not get cleared promptly. While the array is busy the bits will still be cleared when appropriate so this is not very serious. There is no risk to data. Change the test so that we only avoid calling ->run when the thread is being stopped. This more explicitly addresses the problem situation. This is suitable for 2.6.37-stable and any -stable kernel to which 589a594b was applied. Cc: stable@kernel.org Signed-off-by:
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git://git.kernel.org/pub/scm/linux/kernel/git/egtvedt/avr32-2.6Linus Torvalds authored
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/egtvedt/avr32-2.6: avr32: update default configuration files for Atmel boards avr32: Convert to clocksource_register_hz avr32: make architecture sys_clone prototype match asm-generic prototype avr32: use syscall prototypes from asm-generic instead of arch avr32: disable kprobes for all default configurations avr32: boards: setup: use IS_ERR() instead of NULL check
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Trond Myklebust authored
Commit c0204fd2 (NFS: Clean up nfs4_proc_create()) broke NFSv3 exclusive open by removing the code that passes the O_EXCL flag down to nfs3_proc_create(). This patch reverts that offending hunk from the original commit. Reported-by:
Nick Bowler <nbowler@elliptictech.com> Signed-off-by:
Trond Myklebust <Trond.Myklebust@netapp.com> Cc: stable@kernel.org [2.6.37] Tested-by:
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NeilBrown authored
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:Alasdair G Kergon <agk@redhat.com>
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NeilBrown authored
Add per-target unplug callback support. Cc: linux-raid@vger.kernel.org Signed-off-by:
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NeilBrown authored
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:
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Chandra Seetharaman authored
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:
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