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| author | Shaohua Li <shli@fb.com> | 2017-03-27 10:51:37 -0700 |
|---|---|---|
| committer | Jens Axboe <axboe@fb.com> | 2017-03-28 08:02:20 -0600 |
| commit | 297e3d854784821d3b8ff3ae117f20d71f125504 (patch) | |
| tree | 1909a3ce719f5a434d4e4e7584424b3559738be0 /block/blk.h | |
| parent | 06cceedcca67a93ac7f7aa93bbd9980c7496d14e (diff) | |
| download | linux-297e3d854784821d3b8ff3ae117f20d71f125504.tar.bz2 | |
blk-throttle: make throtl_slice tunable
throtl_slice is important for blk-throttling. It's called slice
internally but it really is a time window blk-throttling samples data.
blk-throttling will make decision based on the samplings. An example is
bandwidth measurement. A cgroup's bandwidth is measured in the time
interval of throtl_slice.
A small throtl_slice meanse cgroups have smoother throughput but burn
more CPUs. It has 100ms default value, which is not appropriate for all
disks. A fast SSD can dispatch a lot of IOs in 100ms. This patch makes
it tunable.
Since throtl_slice isn't a time slice, the sysfs name
'throttle_sample_time' reflects its character better.
Signed-off-by: Shaohua Li <shli@fb.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
Diffstat (limited to 'block/blk.h')
| -rw-r--r-- | block/blk.h | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/block/blk.h b/block/blk.h index d1ea4bd9b9a3..bcd3de6c1081 100644 --- a/block/blk.h +++ b/block/blk.h @@ -324,5 +324,10 @@ static inline void blk_throtl_drain(struct request_queue *q) { } static inline int blk_throtl_init(struct request_queue *q) { return 0; } static inline void blk_throtl_exit(struct request_queue *q) { } #endif /* CONFIG_BLK_DEV_THROTTLING */ +#ifdef CONFIG_BLK_DEV_THROTTLING_LOW +extern ssize_t blk_throtl_sample_time_show(struct request_queue *q, char *page); +extern ssize_t blk_throtl_sample_time_store(struct request_queue *q, + const char *page, size_t count); +#endif #endif /* BLK_INTERNAL_H */ |