linux/drivers/md
shli@kernel.org 59fc630b8b RAID5: batch adjacent full stripe write
stripe cache is 4k size. Even adjacent full stripe writes are handled in 4k
unit. Idealy we should use big size for adjacent full stripe writes. Bigger
stripe cache size means less stripes runing in the state machine so can reduce
cpu overhead. And also bigger size can cause bigger IO size dispatched to under
layer disks.

With below patch, we will automatically batch adjacent full stripe write
together. Such stripes will be added to the batch list. Only the first stripe
of the list will be put to handle_list and so run handle_stripe(). Some steps
of handle_stripe() are extended to cover all stripes of the list, including
ops_run_io, ops_run_biodrain and so on. With this patch, we have less stripes
running in handle_stripe() and we send IO of whole stripe list together to
increase IO size.

Stripes added to a batch list have some limitations. A batch list can only
include full stripe write and can't cross chunk boundary to make sure stripes
have the same parity disks. Stripes in a batch list must be in the same state
(no written, toread and so on). If a stripe is in a batch list, all new
read/write to add_stripe_bio will be blocked to overlap conflict till the batch
list is handled. The limitations will make sure stripes in a batch list be in
exactly the same state in the life circly.

I did test running 160k randwrite in a RAID5 array with 32k chunk size and 6
PCIe SSD. This patch improves around 30% performance and IO size to under layer
disk is exactly 32k. I also run a 4k randwrite test in the same array to make
sure the performance isn't changed with the patch.

Signed-off-by: Shaohua Li <shli@fusionio.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2015-04-22 08:00:41 +10:00
..
bcache md/bcache: use generic io stats accounting functions to simplify io stat accounting 2014-11-24 08:05:12 -07:00
persistent-data - Significant dm-crypt CPU scalability performance improvements thanks 2015-02-21 13:28:45 -08:00
bitmap.c md-cluster: re-add capabilities 2015-04-22 07:59:39 +10:00
bitmap.h md-cluster: re-add capabilities 2015-04-22 07:59:39 +10:00
dm-bio-prison.c dm bio prison: introduce support for locking ranges of blocks 2014-11-10 15:25:30 -05:00
dm-bio-prison.h dm bio prison: introduce support for locking ranges of blocks 2014-11-10 15:25:30 -05:00
dm-bio-record.h dm: Refactor for new bio cloning/splitting 2013-11-23 22:33:55 -08:00
dm-bufio.c dm bufio: fix time comparison to use time_after_eq() 2015-02-09 13:06:48 -05:00
dm-bufio.h dm snapshot: use dm-bufio prefetch 2014-01-14 23:23:03 -05:00
dm-builtin.c dm sysfs: fix a module unload race 2014-01-14 23:23:04 -05:00
dm-cache-block-types.h dm cache: revert "remove remainder of distinct discard block size" 2014-11-10 15:25:30 -05:00
dm-cache-metadata.c dm cache: fix missing ERR_PTR returns and handling 2015-01-28 09:59:20 -05:00
dm-cache-metadata.h dm cache: revert "remove remainder of distinct discard block size" 2014-11-10 15:25:30 -05:00
dm-cache-policy-cleaner.c dm cache: policy change version from string to integer set 2013-03-20 17:21:27 +00:00
dm-cache-policy-internal.h dm cache: add remove_cblock method to policy interface 2013-11-11 11:37:50 -05:00
dm-cache-policy-mq.c dm cache policy mq: simplify ability to promote sequential IO to the cache 2014-11-10 15:25:30 -05:00
dm-cache-policy.c dm cache: add policy name to status output 2014-01-16 13:44:11 -05:00
dm-cache-policy.h dm cache: add policy name to status output 2014-01-16 13:44:11 -05:00
dm-cache-target.c - Most significant change this cycle is request-based DM now supports 2015-02-12 16:36:31 -08:00
dm-crypt.c dm crypt: sort writes 2015-02-16 11:11:15 -05:00
dm-delay.c Merge branch 'for-3.14/core' of git://git.kernel.dk/linux-block 2014-01-30 11:19:05 -08:00
dm-era-target.c dm era: check for a non-NULL metadata object before closing it 2014-06-03 13:44:08 -04:00
dm-exception-store.c dm: replace simple_strtoul 2012-07-27 15:07:59 +01:00
dm-exception-store.h dm snapshot: test chunk size against both origin and snapshot 2010-08-12 04:13:51 +01:00
dm-flakey.c block: Abstract out bvec iterator 2013-11-23 22:33:47 -08:00
dm-io.c dm io: deal with wandering queue limits when handling REQ_DISCARD and REQ_WRITE_SAME 2015-02-27 14:53:32 -05:00
dm-ioctl.c dm ioctl: fix stale comment above dm_get_inactive_table() 2015-02-09 13:06:48 -05:00
dm-kcopyd.c dm: stop using WQ_NON_REENTRANT 2013-08-23 09:02:13 -04:00
dm-linear.c block: Abstract out bvec iterator 2013-11-23 22:33:47 -08:00
dm-log-userspace-base.c dm: use time_in_range() and time_after() 2015-02-09 13:06:48 -05:00
dm-log-userspace-transfer.c dm log userspace: fix memory leak in dm_ulog_tfr_init failure path 2014-10-05 20:03:38 -04:00
dm-log-userspace-transfer.h
dm-log.c dm: use memweight() 2012-07-30 17:25:16 -07:00
dm-mpath.c dm mpath: simplify failure path of dm_multipath_init() 2015-02-09 13:06:49 -05:00
dm-mpath.h
dm-path-selector.c md: Add module.h to all files using it implicitly 2011-10-31 19:31:18 -04:00
dm-path-selector.h
dm-queue-length.c dm: reject trailing characters in sccanf input 2012-03-28 18:41:26 +01:00
dm-raid1.c dm mirror: do not degrade the mirror on discard error 2015-02-13 19:50:46 -05:00
dm-raid.c - Most significant change this cycle is request-based DM now supports 2015-02-12 16:36:31 -08:00
dm-region-hash.c block: Abstract out bvec iterator 2013-11-23 22:33:47 -08:00
dm-round-robin.c dm: reject trailing characters in sccanf input 2012-03-28 18:41:26 +01:00
dm-service-time.c dm: reject trailing characters in sccanf input 2012-03-28 18:41:26 +01:00
dm-snap-persistent.c dm snapshot: remove unnecessary NULL checks before vfree() calls 2015-02-09 13:06:49 -05:00
dm-snap-transient.c md: Add in export.h for files using EXPORT_SYMBOL 2011-10-31 19:31:19 -04:00
dm-snap.c dm snapshot: suspend merging snapshot when doing exception handover 2015-02-27 14:53:16 -05:00
dm-stats.c - Significant DM thin-provisioning performance improvements to meet 2014-12-08 21:10:03 -08:00
dm-stats.h dm: add statistics support 2013-09-05 20:46:06 -04:00
dm-stripe.c dm stripe: fix potential for leak in stripe_ctr error path 2014-10-10 22:05:18 -04:00
dm-switch.c dm switch: efficiently support repetitive patterns 2014-08-01 12:30:37 -04:00
dm-sysfs.c dm sysfs: fix a module unload race 2014-01-14 23:23:04 -05:00
dm-table.c dm: inherit QUEUE_FLAG_SG_GAPS flags from underlying queues 2015-02-11 10:25:46 -05:00
dm-target.c dm: allocate requests in target when stacking on blk-mq devices 2015-02-09 13:06:47 -05:00
dm-thin-metadata.c dm thin metadata: remove unused dm_pool_get_data_block_size() 2015-02-09 13:06:49 -05:00
dm-thin-metadata.h dm thin metadata: remove unused dm_pool_get_data_block_size() 2015-02-09 13:06:49 -05:00
dm-thin.c dm thin: fix to consistently zero-fill reads to unprovisioned blocks 2015-02-27 09:59:12 -05:00
dm-uevent.c md: Add in export.h for files using EXPORT_SYMBOL 2011-10-31 19:31:19 -04:00
dm-uevent.h
dm-verity.c dm verity: fix biovecs hash calculation regression 2014-04-15 12:19:24 -04:00
dm-zero.c dm crypt, dm zero: update author name following legal name change 2014-07-10 16:44:14 -04:00
dm.c dm: fix add_disk() NULL pointer due to race with free_dev() 2015-03-23 18:14:00 -04:00
dm.h dm table: train hybrid target type detection to select blk-mq if appropriate 2015-02-09 13:06:47 -05:00
faulty.c md: rename ->stop to ->free 2015-02-04 08:35:52 +11:00
Kconfig Create a separate module for clustering support 2015-02-23 07:28:42 -06:00
linear.c md: rename ->stop to ->free 2015-02-04 08:35:52 +11:00
linear.h md/linear: typedef removal: linear_conf_t -> struct linear_conf 2011-10-11 16:48:54 +11:00
Makefile Create a separate module for clustering support 2015-02-23 07:28:42 -06:00
md-cluster.c md-cluster: re-add capabilities 2015-04-22 07:59:39 +10:00
md-cluster.h md-cluster: re-add capabilities 2015-04-22 07:59:39 +10:00
md.c md: allow resync to go faster when there is competing IO. 2015-04-22 08:00:40 +10:00
md.h md: remove 'go_faster' option from ->sync_request() 2015-04-22 08:00:40 +10:00
multipath.c md: rename ->stop to ->free 2015-02-04 08:35:52 +11:00
multipath.h md/multipath: typedef removal: multipath_conf_t -> struct mpconf 2011-10-11 16:48:57 +11:00
raid0.c md raid0: access mddev->queue (request queue member) conditionally because it is not set when accessed from dm-raid 2015-04-22 08:00:41 +10:00
raid0.h md: add proper merge_bvec handling to RAID0 and Linear. 2012-03-19 12:46:39 +11:00
raid1.c md: remove 'go_faster' option from ->sync_request() 2015-04-22 08:00:40 +10:00
raid1.h md: make ->congested robust against personality changes. 2015-02-04 08:35:52 +11:00
raid5.c RAID5: batch adjacent full stripe write 2015-04-22 08:00:41 +10:00
raid5.h RAID5: batch adjacent full stripe write 2015-04-22 08:00:41 +10:00
raid10.c md: remove 'go_faster' option from ->sync_request() 2015-04-22 08:00:40 +10:00
raid10.h md: make ->congested robust against personality changes. 2015-02-04 08:35:52 +11:00