Michael Lyle 1d316e6583 bcache: implement PI controller for writeback rate ... bcache uses a control system to attempt to keep the amount of dirty data in cache at a user-configured level, while not responding excessively to transients and variations in write rate. Previously, the system was a PD controller; but the output from it was integrated, turning the Proportional term into an Integral term, and turning the Derivative term into a crude Proportional term. Performance of the controller has been uneven in production, and it has tended to respond slowly, oscillate, and overshoot. This patch set replaces the current control system with an explicit PI controller and tuning that should be correct for most hardware. By default, it attempts to write at a rate that would retire 1/40th of the current excess blocks per second. An integral term in turn works to remove steady state errors. IMO, this yields benefits in simplicity (removing weighted average filtering, etc) and system performance. Another small change is a tunable parameter is introduced to allow the user to specify a minimum rate at which dirty blocks are retired. There is a slight difference from earlier versions of the patch in integral handling to prevent excessive negative integral windup. Signed-off-by: Michael Lyle <mlyle@lyle.org> Reviewed-by: Coly Li <colyli@suse.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>		2017-10-16 09:07:26 -06:00
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bcache	bcache: implement PI controller for writeback rate	2017-10-16 09:07:26 -06:00
persistent-data	dm space map disk: fix some book keeping in the disk space map	2017-05-15 15:09:50 -04:00
bitmap.c	buffer: have alloc_page_buffers() use __GFP_NOFAIL	2017-10-03 08:38:17 -06:00
bitmap.h
dm-bio-prison-v1.c	dm bio prison: use rb_entry() rather than container_of()	2017-06-19 11:03:50 -04:00
dm-bio-prison-v1.h	block: switch bios to blk_status_t	2017-06-09 09:27:32 -06:00
dm-bio-prison-v2.c	dm bio prison: use rb_entry() rather than container_of()	2017-06-19 11:03:50 -04:00
dm-bio-prison-v2.h
dm-bio-record.h	block: replace bi_bdev with a gendisk pointer and partitions index	2017-08-23 12:49:55 -06:00
dm-bufio.c	- Some request-based DM core and DM multipath fixes and cleanups	2017-09-14 13:43:16 -07:00
dm-bufio.h	dm integrity: optimize writing dm-bufio buffers that are partially changed	2017-08-28 11:47:17 -04:00
dm-builtin.c
dm-cache-background-tracker.c	dm cache: handle kmalloc failure allocating background_tracker struct	2017-05-17 09:44:53 -04:00
dm-cache-background-tracker.h
dm-cache-block-types.h
dm-cache-metadata.c	dm cache metadata: fail operations if fail_io mode has been established	2017-05-05 14:40:13 -04:00
dm-cache-metadata.h
dm-cache-policy-internal.h
dm-cache-policy-smq.c	dm cache policy smq: don't do any writebacks unless IDLE	2017-05-14 21:54:33 -04:00
dm-cache-policy.c
dm-cache-policy.h
dm-cache-target.c	- Some request-based DM core and DM multipath fixes and cleanups	2017-09-14 13:43:16 -07:00
dm-core.h	dm: add basic support for using the select or poll function	2017-06-19 11:03:49 -04:00
dm-crypt.c	- Some request-based DM core and DM multipath fixes and cleanups	2017-09-14 13:43:16 -07:00
dm-delay.c	block: replace bi_bdev with a gendisk pointer and partitions index	2017-08-23 12:49:55 -06:00
dm-era-target.c	block: replace bi_bdev with a gendisk pointer and partitions index	2017-08-23 12:49:55 -06:00
dm-exception-store.c
dm-exception-store.h
dm-flakey.c	- Some request-based DM core and DM multipath fixes and cleanups	2017-09-14 13:43:16 -07:00
dm-integrity.c	- Some request-based DM core and DM multipath fixes and cleanups	2017-09-14 13:43:16 -07:00
dm-io.c	block: replace bi_bdev with a gendisk pointer and partitions index	2017-08-23 12:49:55 -06:00
dm-ioctl.c	dm ioctl: constify ioctl lookup table	2017-08-28 11:47:18 -04:00
dm-kcopyd.c	dm kcopyd: add sequential write feature	2017-06-19 11:03:51 -04:00
dm-linear.c	- Some request-based DM core and DM multipath fixes and cleanups	2017-09-14 13:43:16 -07:00
dm-log-userspace-base.c
dm-log-userspace-transfer.c
dm-log-userspace-transfer.h
dm-log-writes.c	- Some request-based DM core and DM multipath fixes and cleanups	2017-09-14 13:43:16 -07:00
dm-log.c
dm-mpath.c	- Some request-based DM core and DM multipath fixes and cleanups	2017-09-14 13:43:16 -07:00
dm-mpath.h
dm-path-selector.c
dm-path-selector.h
dm-queue-length.c
dm-raid1.c	block: replace bi_bdev with a gendisk pointer and partitions index	2017-08-23 12:49:55 -06:00
dm-raid.c	dm raid: bump target version	2017-07-25 14:54:20 -04:00
dm-region-hash.c
dm-round-robin.c
dm-rq.c	block: remove QUEUE_FLAG_STACKABLE	2017-10-05 15:22:59 -06:00
dm-rq.h	dm rq: do not update rq partially in each ending bio	2017-08-28 10:23:28 -04:00
dm-service-time.c
dm-snap-persistent.c	dm: make flush bios explicitly sync	2017-05-31 10:50:23 -04:00
dm-snap-transient.c
dm-snap.c	block: replace bi_bdev with a gendisk pointer and partitions index	2017-08-23 12:49:55 -06:00
dm-stats.c	mm: introduce kv[mz]alloc helpers	2017-05-08 17:15:12 -07:00
dm-stats.h
dm-stripe.c	- Some request-based DM core and DM multipath fixes and cleanups	2017-09-14 13:43:16 -07:00
dm-switch.c	- Some request-based DM core and DM multipath fixes and cleanups	2017-09-14 13:43:16 -07:00
dm-sysfs.c
dm-table.c	block: remove QUEUE_FLAG_STACKABLE	2017-10-05 15:22:59 -06:00
dm-target.c	dm: don't return errnos from ->map	2017-06-09 09:27:32 -06:00
dm-thin-metadata.c	dm thin metadata: call precommit before saving the roots	2017-05-15 15:09:49 -04:00
dm-thin-metadata.h
dm-thin.c	- Some request-based DM core and DM multipath fixes and cleanups	2017-09-14 13:43:16 -07:00
dm-uevent.c
dm-uevent.h
dm-verity-fec.c	dm verity fec: fix GFP flags used with mempool_alloc()	2017-07-26 15:55:44 -04:00
dm-verity-fec.h
dm-verity-target.c	- Some request-based DM core and DM multipath fixes and cleanups	2017-09-14 13:43:16 -07:00
dm-verity.h	dm verity: switch to using asynchronous hash crypto API	2017-04-24 15:37:04 -04:00
dm-zero.c	dm: don't return errnos from ->map	2017-06-09 09:27:32 -06:00
dm-zoned-metadata.c	block: replace bi_bdev with a gendisk pointer and partitions index	2017-08-23 12:49:55 -06:00
dm-zoned-reclaim.c	dm zoned: use GFP_NOIO in I/O path	2017-07-26 15:55:43 -04:00
dm-zoned-target.c	block: replace bi_bdev with a gendisk pointer and partitions index	2017-08-23 12:49:55 -06:00
dm-zoned.h	dm zoned: drive-managed zoned block device target	2017-06-19 11:05:20 -04:00
dm.c	block: remove QUEUE_FLAG_STACKABLE	2017-10-05 15:22:59 -06:00
dm.h	dm: introduce enum dm_queue_mode to cleanup related code	2017-04-27 17:08:44 -04:00
faulty.c	block: replace bi_bdev with a gendisk pointer and partitions index	2017-08-23 12:49:55 -06:00
Kconfig	dm zoned: drive-managed zoned block device target	2017-06-19 11:05:20 -04:00
linear.c	block: replace bi_bdev with a gendisk pointer and partitions index	2017-08-23 12:49:55 -06:00
linear.h
Makefile	dm zoned: drive-managed zoned block device target	2017-06-19 11:05:20 -04:00
md-cluster.c	md-cluster: fix potential lock issue in add_new_disk	2017-05-21 20:37:09 -07:00
md-cluster.h
md.c	Merge tag 'md/4.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/shli/md	2017-09-07 12:41:48 -07:00
md.h	Merge tag 'md/4.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/shli/md	2017-09-07 12:41:48 -07:00
multipath.c	block: replace bi_bdev with a gendisk pointer and partitions index	2017-08-23 12:49:55 -06:00
multipath.h
raid0.c	Merge tag 'md/4.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/shli/md	2017-09-07 12:41:48 -07:00
raid0.h
raid1-10.c	md: raid1-10: move raid1/raid10 common code into raid1-10.c	2017-07-21 12:47:20 -07:00
raid1.c	Merge tag 'md/4.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/shli/md	2017-09-07 12:41:48 -07:00
raid1.h	md/raid1: Use a new variable to count flighting sync requests	2017-04-27 14:01:16 -07:00
raid5-cache.c	Merge tag 'md/4.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/shli/md	2017-09-07 12:41:48 -07:00
raid5-log.h	md/r5cache: gracefully handle journal device errors for writeback mode	2017-05-11 22:11:11 -07:00
raid5-ppl.c	Merge tag 'md/4.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/shli/md	2017-09-07 12:41:48 -07:00
raid5.c	Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/shli/md	2017-09-19 08:39:32 -07:00
raid5.h	- A major update for DM cache that reduces the latency for deciding	2017-05-03 10:31:20 -07:00
raid10.c	Merge tag 'md/4.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/shli/md	2017-09-07 12:41:48 -07:00
raid10.h	md/raid10: simplify the splitting of requests.	2017-04-11 10:13:02 -07:00