linux/block
Paolo Valente e24f1c245f block, bfq: remove slow-system class
BFQ computes the duration of weight raising for interactive
applications automatically, using some reference parameters. In
particular, BFQ uses the best durations (see comments in the code for
how these durations have been assessed) for two classes of systems:
slow and fast ones. Examples of slow systems are old phones or systems
using micro HDDs. Fast systems are all the remaining ones. Using these
parameters, BFQ computes the actual duration of the weight raising,
for the system at hand, as a function of the relative speed of the
system w.r.t. the speed of a reference system, belonging to the same
class of systems as the system at hand.

This slow vs fast differentiation proved to be useful in the past, but
happens to have little meaning with current hardware. Even worse, it
does cause problems in virtual systems, where the speed of the system
can vary frequently, and so widely to just confuse the class-detection
mechanism, and, as we have verified experimentally, to cause BFQ to
compute non-sensical weight-raising durations.

This commit addresses this issue by removing the slow class and the
class-detection mechanism.

Signed-off-by: Paolo Valente <paolo.valente@linaro.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-05-31 08:54:38 -06:00
..
partitions partitions/msdos: Unable to mount UFS 44bsd partitions 2018-01-10 09:12:16 -07:00
badblocks.c badblocks: fix wrong return value in badblocks_set if badblocks are disabled 2017-11-03 11:29:50 -07:00
bfq-cgroup.c block: use ktime_get_ns() instead of sched_clock() for cfq and bfq 2018-05-09 08:33:06 -06:00
bfq-iosched.c block, bfq: remove slow-system class 2018-05-31 08:54:38 -06:00
bfq-iosched.h block, bfq: remove slow-system class 2018-05-31 08:54:38 -06:00
bfq-wf2q.c block, bfq: limit sectors served with interactive weight raising 2018-01-18 08:21:37 -07:00
bio-integrity.c block: Convert bio_set to mempool_init() 2018-05-14 13:16:03 -06:00
bio.c block: Drop bioset_create() 2018-05-30 15:33:32 -06:00
blk-cgroup.c blkcg: init root blkcg_gq under lock 2018-04-19 08:51:59 -06:00
blk-core.c block: convert bounce, q->bio_split to bioset_init()/mempool_init() 2018-05-30 15:33:32 -06:00
blk-exec.c blk-mq-sched: remove unused 'can_block' arg from blk_mq_sched_insert_request 2018-01-17 09:49:21 -07:00
blk-flush.c blk-mq: don't allocate driver tag upfront for flush rq 2017-11-04 12:40:13 -06:00
blk-integrity.c block drivers/block: Use octal not symbolic permissions 2018-05-24 13:38:59 -06:00
blk-ioc.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
blk-lib.c block: break discard submissions into the user defined size 2018-05-08 15:10:44 -06:00
blk-map.c Merge branch 'for-4.16/block' of git://git.kernel.dk/linux-block 2018-01-29 11:51:49 -08:00
blk-merge.c block: convert bounce, q->bio_split to bioset_init()/mempool_init() 2018-05-30 15:33:32 -06:00
blk-mq-cpumap.c blk-mq: don't keep offline CPUs mapped to hctx 0 2018-04-10 08:38:46 -06:00
blk-mq-debugfs.c blk-mq: Remove generation seqeunce 2018-05-29 08:59:21 -06:00
blk-mq-debugfs.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
blk-mq-pci.c blk-mq: Allow PCI vector offset for mapping queues 2018-03-27 21:25:36 -06:00
blk-mq-rdma.c block: Add rdma affinity based queue mapping helper 2017-08-08 14:58:03 -04:00
blk-mq-sched.c blk-mq: abstract out blk-mq-sched rq list iteration bio merge helper 2018-05-30 10:43:58 -06:00
blk-mq-sched.h blk-mq-sched: remove unused 'can_block' arg from blk_mq_sched_insert_request 2018-01-17 09:49:21 -07:00
blk-mq-sysfs.c block drivers/block: Use octal not symbolic permissions 2018-05-24 13:38:59 -06:00
blk-mq-tag.c blk-mq: only iterate over inflight requests in blk_mq_tagset_busy_iter 2018-05-30 11:31:34 -06:00
blk-mq-tag.h Merge branch 'for-4.15/block' of git://git.kernel.dk/linux-block 2017-11-14 15:32:19 -08:00
blk-mq-virtio.c blk-mq: provide a default queue mapping for virtio device 2017-02-27 20:54:05 +02:00
blk-mq.c blk-mq: simplify blk_mq_rq_timed_out 2018-05-29 08:59:21 -06:00
blk-mq.h blk-mq: Remove generation seqeunce 2018-05-29 08:59:21 -06:00
blk-settings.c block: Introduce blk_queue_flag_{set,clear,test_and_{set,clear}}() 2018-03-08 14:13:48 -07:00
blk-softirq.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
blk-stat.c block: consolidate struct request timestamp fields 2018-05-09 08:33:09 -06:00
blk-stat.h block: consolidate struct request timestamp fields 2018-05-09 08:33:09 -06:00
blk-sysfs.c block: convert bounce, q->bio_split to bioset_init()/mempool_init() 2018-05-30 15:33:32 -06:00
blk-tag.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
blk-throttle.c blk-throttle: return proper bool type to caller instead of 0/1 2018-05-30 12:48:22 -06:00
blk-timeout.c block: remove BLK_EH_HANDLED 2018-05-29 08:59:21 -06:00
blk-wbt.c block: get rid of struct blk_issue_stat 2018-05-09 08:33:05 -06:00
blk-wbt.h block: get rid of struct blk_issue_stat 2018-05-09 08:33:05 -06:00
blk-zoned.c blkdev_report_zones_ioctl(): Use vmalloc() to allocate large buffers 2018-05-22 11:58:07 -06:00
blk.h block: consolidate struct request timestamp fields 2018-05-09 08:33:09 -06:00
bounce.c block: fixup bioset_integrity_create() call 2018-05-30 18:51:21 -06:00
bsg-lib.c block: remove parent device reference from struct bsg_class_device 2018-05-29 13:00:25 -06:00
bsg.c block: remove parent device reference from struct bsg_class_device 2018-05-29 13:00:25 -06:00
cfq-iosched.c block drivers/block: Use octal not symbolic permissions 2018-05-24 13:38:59 -06:00
cmdline-parser.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
compat_ioctl.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
deadline-iosched.c block drivers/block: Use octal not symbolic permissions 2018-05-24 13:38:59 -06:00
elevator.c block: Document scheduler modification locking requirements 2018-01-18 12:54:42 -07:00
genhd.c block drivers/block: Use octal not symbolic permissions 2018-05-24 13:38:59 -06:00
ioctl.c block: pass inclusive 'lend' parameter to truncate_inode_pages_range 2018-02-23 15:20:19 -07:00
ioprio.c block: Add fallthrough markers to switch statements 2017-06-21 11:46:07 -06:00
Kconfig License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
Kconfig.iosched License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
kyber-iosched.c block: kyber: make kyber more friendly with merging 2018-05-30 10:47:40 -06:00
Makefile License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
mq-deadline.c block drivers/block: Use octal not symbolic permissions 2018-05-24 13:38:59 -06:00
noop-iosched.c block: move existing elevator ops to union 2017-01-17 10:03:33 -07:00
opal_proto.h block: sed-opal: Set MBRDone on S3 resume path if TPER is MBREnabled 2017-09-11 09:45:52 -06:00
partition-generic.c block: don't print a message when the device went away 2018-05-29 08:59:21 -06:00
scsi_ioctl.c block: consistently use GFP_NOIO instead of __GFP_NORECLAIM 2018-05-14 08:55:18 -06:00
sed-opal.c for-4.17/block-20180402 2018-04-05 14:27:02 -07:00
t10-pi.c t10-pi: Move opencoded contants to common header 2017-07-03 16:56:25 -06:00