From e8368b57c006dc0e02dcd8a9dc9f2060ff5476fe Mon Sep 17 00:00:00 2001 From: Yu Kuai Date: Wed, 16 Aug 2023 09:27:07 +0800 Subject: blk-throttle: use calculate_io/bytes_allowed() for throtl_trim_slice() There are no functional changes, just make the code cleaner. Signed-off-by: Yu Kuai Acked-by: Tejun Heo Link: https://lore.kernel.org/r/20230816012708.1193747-4-yukuai1@huaweicloud.com Signed-off-by: Jens Axboe --- block/blk-throttle.c | 86 +++++++++++++++++++++++++--------------------------- 1 file changed, 41 insertions(+), 45 deletions(-) (limited to 'block') diff --git a/block/blk-throttle.c b/block/blk-throttle.c index 7c93144d03da5..69a9941567721 100644 --- a/block/blk-throttle.c +++ b/block/blk-throttle.c @@ -697,11 +697,40 @@ static bool throtl_slice_used(struct throtl_grp *tg, bool rw) return true; } +static unsigned int calculate_io_allowed(u32 iops_limit, + unsigned long jiffy_elapsed) +{ + unsigned int io_allowed; + u64 tmp; + + /* + * jiffy_elapsed should not be a big value as minimum iops can be + * 1 then at max jiffy elapsed should be equivalent of 1 second as we + * will allow dispatch after 1 second and after that slice should + * have been trimmed. + */ + + tmp = (u64)iops_limit * jiffy_elapsed; + do_div(tmp, HZ); + + if (tmp > UINT_MAX) + io_allowed = UINT_MAX; + else + io_allowed = tmp; + + return io_allowed; +} + +static u64 calculate_bytes_allowed(u64 bps_limit, unsigned long jiffy_elapsed) +{ + return mul_u64_u64_div_u64(bps_limit, (u64)jiffy_elapsed, (u64)HZ); +} + /* Trim the used slices and adjust slice start accordingly */ static inline void throtl_trim_slice(struct throtl_grp *tg, bool rw) { - unsigned long nr_slices, time_elapsed, io_trim; - u64 bytes_trim, tmp; + unsigned long time_elapsed, io_trim; + u64 bytes_trim; BUG_ON(time_before(tg->slice_end[rw], tg->slice_start[rw])); @@ -723,19 +752,14 @@ static inline void throtl_trim_slice(struct throtl_grp *tg, bool rw) throtl_set_slice_end(tg, rw, jiffies + tg->td->throtl_slice); - time_elapsed = jiffies - tg->slice_start[rw]; - - nr_slices = time_elapsed / tg->td->throtl_slice; - - if (!nr_slices) + time_elapsed = rounddown(jiffies - tg->slice_start[rw], + tg->td->throtl_slice); + if (!time_elapsed) return; - tmp = tg_bps_limit(tg, rw) * tg->td->throtl_slice * nr_slices; - do_div(tmp, HZ); - bytes_trim = tmp; - - io_trim = (tg_iops_limit(tg, rw) * tg->td->throtl_slice * nr_slices) / - HZ; + bytes_trim = calculate_bytes_allowed(tg_bps_limit(tg, rw), + time_elapsed); + io_trim = calculate_io_allowed(tg_iops_limit(tg, rw), time_elapsed); if (!bytes_trim && !io_trim) return; @@ -749,41 +773,13 @@ static inline void throtl_trim_slice(struct throtl_grp *tg, bool rw) else tg->io_disp[rw] = 0; - tg->slice_start[rw] += nr_slices * tg->td->throtl_slice; + tg->slice_start[rw] += time_elapsed; throtl_log(&tg->service_queue, "[%c] trim slice nr=%lu bytes=%llu io=%lu start=%lu end=%lu jiffies=%lu", - rw == READ ? 'R' : 'W', nr_slices, bytes_trim, io_trim, - tg->slice_start[rw], tg->slice_end[rw], jiffies); -} - -static unsigned int calculate_io_allowed(u32 iops_limit, - unsigned long jiffy_elapsed) -{ - unsigned int io_allowed; - u64 tmp; - - /* - * jiffy_elapsed should not be a big value as minimum iops can be - * 1 then at max jiffy elapsed should be equivalent of 1 second as we - * will allow dispatch after 1 second and after that slice should - * have been trimmed. - */ - - tmp = (u64)iops_limit * jiffy_elapsed; - do_div(tmp, HZ); - - if (tmp > UINT_MAX) - io_allowed = UINT_MAX; - else - io_allowed = tmp; - - return io_allowed; -} - -static u64 calculate_bytes_allowed(u64 bps_limit, unsigned long jiffy_elapsed) -{ - return mul_u64_u64_div_u64(bps_limit, (u64)jiffy_elapsed, (u64)HZ); + rw == READ ? 'R' : 'W', time_elapsed / tg->td->throtl_slice, + bytes_trim, io_trim, tg->slice_start[rw], tg->slice_end[rw], + jiffies); } static void __tg_update_carryover(struct throtl_grp *tg, bool rw) -- cgit 1.2.3-korg