From d61fcfa4bb18992dc8e171996808e1034dc643bb Mon Sep 17 00:00:00 2001 From: Shaohua Li Date: Mon, 27 Mar 2017 10:51:38 -0700 Subject: [PATCH] blk-throttle: choose a small throtl_slice for SSD The throtl_slice is 100ms by default. This is a long time for SSD, a lot of IO can run. To make cgroups have smoother throughput, we choose a small value (20ms) for SSD. Signed-off-by: Shaohua Li Signed-off-by: Jens Axboe --- block/blk-sysfs.c | 2 ++ block/blk-throttle.c | 23 ++++++++++++++++++++--- block/blk.h | 2 ++ 3 files changed, 24 insertions(+), 3 deletions(-) diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c index b315e62..7f090dd 100644 --- a/block/blk-sysfs.c +++ b/block/blk-sysfs.c @@ -906,6 +906,8 @@ int blk_register_queue(struct gendisk *disk) blk_wb_init(q); + blk_throtl_register_queue(q); + if (q->request_fn || (q->mq_ops && q->elevator)) { ret = elv_register_queue(q); if (ret) { diff --git a/block/blk-throttle.c b/block/blk-throttle.c index 93841da..d00c1c1 100644 --- a/block/blk-throttle.c +++ b/block/blk-throttle.c @@ -18,8 +18,9 @@ static int throtl_grp_quantum = 8; /* Total max dispatch from all groups in one round */ static int throtl_quantum = 32; -/* Throttling is performed over 100ms slice and after that slice is renewed */ -#define DFL_THROTL_SLICE (HZ / 10) +/* Throttling is performed over a slice and after that slice is renewed */ +#define DFL_THROTL_SLICE_HD (HZ / 10) +#define DFL_THROTL_SLICE_SSD (HZ / 50) #define MAX_THROTL_SLICE (HZ) static struct blkcg_policy blkcg_policy_throtl; @@ -1961,7 +1962,6 @@ int blk_throtl_init(struct request_queue *q) q->td = td; td->queue = q; - td->throtl_slice = DFL_THROTL_SLICE; td->limit_valid[LIMIT_MAX] = true; td->limit_index = LIMIT_MAX; @@ -1982,6 +1982,23 @@ void blk_throtl_exit(struct request_queue *q) kfree(q->td); } +void blk_throtl_register_queue(struct request_queue *q) +{ + struct throtl_data *td; + + td = q->td; + BUG_ON(!td); + + if (blk_queue_nonrot(q)) + td->throtl_slice = DFL_THROTL_SLICE_SSD; + else + td->throtl_slice = DFL_THROTL_SLICE_HD; +#ifndef CONFIG_BLK_DEV_THROTTLING_LOW + /* if no low limit, use previous default */ + td->throtl_slice = DFL_THROTL_SLICE_HD; +#endif +} + #ifdef CONFIG_BLK_DEV_THROTTLING_LOW ssize_t blk_throtl_sample_time_show(struct request_queue *q, char *page) { diff --git a/block/blk.h b/block/blk.h index bcd3de6..13070c3 100644 --- a/block/blk.h +++ b/block/blk.h @@ -319,10 +319,12 @@ static inline struct io_context *create_io_context(gfp_t gfp_mask, int node) extern void blk_throtl_drain(struct request_queue *q); extern int blk_throtl_init(struct request_queue *q); extern void blk_throtl_exit(struct request_queue *q); +extern void blk_throtl_register_queue(struct request_queue *q); #else /* CONFIG_BLK_DEV_THROTTLING */ 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) { } +static inline void blk_throtl_register_queue(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); -- 2.7.4