linux/drivers/md/bcache
Coly Li 9aaf516546 bcache: make cutoff_writeback and cutoff_writeback_sync tunable
Currently the cutoff writeback and cutoff writeback sync thresholds are
defined by CUTOFF_WRITEBACK (40) and CUTOFF_WRITEBACK_SYNC (70) as
static values. Most of time these they work fine, but when people want
to do research on bcache writeback mode performance tuning, there is no
chance to modify the soft and hard cutoff writeback values.

This patch introduces two module parameters bch_cutoff_writeback_sync
and bch_cutoff_writeback which permit people to tune the values when
loading bcache.ko. If they are not specified by module loading, current
values CUTOFF_WRITEBACK_SYNC and CUTOFF_WRITEBACK will be used as
default and nothing changes.

When people want to tune this two values,
- cutoff_writeback can be set in range [1, 70]
- cutoff_writeback_sync can be set in range [1, 90]
- cutoff_writeback always <= cutoff_writeback_sync

The default values are strongly recommended to most of users for most of
workloads. Anyway, if people wants to take their own risk to do research
on new writeback cutoff tuning for their own workload, now they can make
it.

Signed-off-by: Coly Li <colyli@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-12-13 08:15:54 -07:00
..
alloc.c bcache: use MAX_CACHES_PER_SET instead of magic number 8 in __bch_bucket_alloc_set 2018-10-08 08:19:56 -06:00
bcache.h bcache: option to automatically run gc thread after writeback 2018-12-13 08:15:54 -07:00
bset.c bcache: fix code comments style 2018-08-11 15:46:42 -06:00
bset.h bcache: style fixes for lines over 80 characters 2018-08-11 15:46:41 -06:00
btree.c bcache: add comment for cache_set->fill_iter 2018-12-13 08:15:54 -07:00
btree.h bcache: introduce force_wake_up_gc() 2018-12-13 08:15:54 -07:00
closure.c bcache: add missing SPDX header 2018-08-11 15:46:42 -06:00
closure.h bcache: fix typo in code comments of closure_return_with_destructor() 2018-10-08 08:19:43 -06:00
debug.c bcache: do not check if debug dentry is ERR or NULL explicitly on remove 2018-12-13 08:15:54 -07:00
debug.h bcache: add identifier names to arguments of function definitions 2018-08-11 15:46:41 -06:00
extents.c bcache: replace hard coded number with BUCKET_GC_GEN_MAX 2018-10-08 08:19:55 -06:00
extents.h bcache: add identifier names to arguments of function definitions 2018-08-11 15:46:41 -06:00
io.c bcache: fix typo 'succesfully' to 'successfully' 2018-08-11 15:46:42 -06:00
journal.c bcache: add separate workqueue for journal_write to avoid deadlock 2018-09-27 09:47:01 -06:00
journal.h bcache: add identifier names to arguments of function definitions 2018-08-11 15:46:41 -06:00
Kconfig for-4.19/post-20180822 2018-08-22 13:38:05 -07:00
Makefile License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
movinggc.c bcache: style fix to add a blank line after declarations 2018-08-11 15:46:41 -06:00
request.c bcache: update comment for bch_data_insert 2018-12-13 08:15:54 -07:00
request.h bcache: remove unused bch_passthrough_cache 2018-10-08 08:19:52 -06:00
stats.c bcache: style fix to add a blank line after declarations 2018-08-11 15:46:41 -06:00
stats.h bcache: add identifier names to arguments of function definitions 2018-08-11 15:46:41 -06:00
super.c bcache: make cutoff_writeback and cutoff_writeback_sync tunable 2018-12-13 08:15:54 -07:00
sysfs.c bcache: make cutoff_writeback and cutoff_writeback_sync tunable 2018-12-13 08:15:54 -07:00
sysfs.h bcache: replace Symbolic permissions by octal permission numbers 2018-08-11 15:46:41 -06:00
trace.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
util.c for-4.19/post-20180822 2018-08-22 13:38:05 -07:00
util.h for-4.19/post-20180822 2018-08-22 13:38:05 -07:00
writeback.c bcache: option to automatically run gc thread after writeback 2018-12-13 08:15:54 -07:00
writeback.h bcache: make cutoff_writeback and cutoff_writeback_sync tunable 2018-12-13 08:15:54 -07:00