From 0f3457f60edc57332bf6564fa00d561a4372dcb9 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Tue, 14 May 2013 13:52:32 -0700 Subject: [PATCH] blk-throttle: add backlink pointer from throtl_grp to throtl_data Add throtl_grp->td so that the td (throtl_data) a given tg (throtl_grp) belongs to can be determined, and remove @td argument from functions which take both @td and @tg as the former now can be determined from the latter. This generally simplifies the code and removes a number of cases where @td is passed as an argument without being actually used. This will also help hierarchy support implementation. While at it, in multi-line conditions, move the logical operators leading broken lines to the end of the previous line. Signed-off-by: Tejun Heo Acked-by: Vivek Goyal --- block/blk-throttle.c | 106 +++++++++++++++++++++---------------------- 1 file changed, 53 insertions(+), 53 deletions(-) diff --git a/block/blk-throttle.c b/block/blk-throttle.c index e8ef43d3fab3..a489391f9153 100644 --- a/block/blk-throttle.c +++ b/block/blk-throttle.c @@ -57,6 +57,9 @@ struct throtl_grp { /* active throtl group service_queue member */ struct rb_node rb_node; + /* throtl_data this group belongs to */ + struct throtl_data *td; + /* * Dispatch time in jiffies. This is the estimated time when group * will unthrottle and is ready to dispatch more bio. It is used as @@ -140,11 +143,11 @@ static inline struct throtl_grp *td_root_tg(struct throtl_data *td) return blkg_to_tg(td->queue->root_blkg); } -#define throtl_log_tg(td, tg, fmt, args...) do { \ +#define throtl_log_tg(tg, fmt, args...) do { \ char __pbuf[128]; \ \ blkg_path(tg_to_blkg(tg), __pbuf, sizeof(__pbuf)); \ - blk_add_trace_msg((td)->queue, "throtl %s " fmt, __pbuf, ##args); \ + blk_add_trace_msg((tg)->td->queue, "throtl %s " fmt, __pbuf, ##args); \ } while (0) #define throtl_log(td, fmt, args...) \ @@ -193,6 +196,7 @@ static void throtl_pd_init(struct blkcg_gq *blkg) unsigned long flags; RB_CLEAR_NODE(&tg->rb_node); + tg->td = blkg->q->td; bio_list_init(&tg->bio_lists[0]); bio_list_init(&tg->bio_lists[1]); @@ -401,36 +405,34 @@ static void throtl_schedule_next_dispatch(struct throtl_data *td) throtl_schedule_delayed_work(td, sq->first_pending_disptime - jiffies); } -static inline void -throtl_start_new_slice(struct throtl_data *td, struct throtl_grp *tg, bool rw) +static inline void throtl_start_new_slice(struct throtl_grp *tg, bool rw) { tg->bytes_disp[rw] = 0; tg->io_disp[rw] = 0; tg->slice_start[rw] = jiffies; tg->slice_end[rw] = jiffies + throtl_slice; - throtl_log_tg(td, tg, "[%c] new slice start=%lu end=%lu jiffies=%lu", + throtl_log_tg(tg, "[%c] new slice start=%lu end=%lu jiffies=%lu", rw == READ ? 'R' : 'W', tg->slice_start[rw], tg->slice_end[rw], jiffies); } -static inline void throtl_set_slice_end(struct throtl_data *td, - struct throtl_grp *tg, bool rw, unsigned long jiffy_end) +static inline void throtl_set_slice_end(struct throtl_grp *tg, bool rw, + unsigned long jiffy_end) { tg->slice_end[rw] = roundup(jiffy_end, throtl_slice); } -static inline void throtl_extend_slice(struct throtl_data *td, - struct throtl_grp *tg, bool rw, unsigned long jiffy_end) +static inline void throtl_extend_slice(struct throtl_grp *tg, bool rw, + unsigned long jiffy_end) { tg->slice_end[rw] = roundup(jiffy_end, throtl_slice); - throtl_log_tg(td, tg, "[%c] extend slice start=%lu end=%lu jiffies=%lu", + throtl_log_tg(tg, "[%c] extend slice start=%lu end=%lu jiffies=%lu", rw == READ ? 'R' : 'W', tg->slice_start[rw], tg->slice_end[rw], jiffies); } /* Determine if previously allocated or extended slice is complete or not */ -static bool -throtl_slice_used(struct throtl_data *td, struct throtl_grp *tg, bool rw) +static bool throtl_slice_used(struct throtl_grp *tg, bool rw) { if (time_in_range(jiffies, tg->slice_start[rw], tg->slice_end[rw])) return 0; @@ -439,8 +441,7 @@ throtl_slice_used(struct throtl_data *td, struct throtl_grp *tg, bool rw) } /* Trim the used slices and adjust slice start accordingly */ -static inline void -throtl_trim_slice(struct throtl_data *td, struct throtl_grp *tg, bool rw) +static inline void throtl_trim_slice(struct throtl_grp *tg, bool rw) { unsigned long nr_slices, time_elapsed, io_trim; u64 bytes_trim, tmp; @@ -452,7 +453,7 @@ throtl_trim_slice(struct throtl_data *td, struct throtl_grp *tg, bool rw) * renewed. Don't try to trim the slice if slice is used. A new * slice will start when appropriate. */ - if (throtl_slice_used(td, tg, rw)) + if (throtl_slice_used(tg, rw)) return; /* @@ -463,7 +464,7 @@ throtl_trim_slice(struct throtl_data *td, struct throtl_grp *tg, bool rw) * is bad because it does not allow new slice to start. */ - throtl_set_slice_end(td, tg, rw, jiffies + throtl_slice); + throtl_set_slice_end(tg, rw, jiffies + throtl_slice); time_elapsed = jiffies - tg->slice_start[rw]; @@ -492,14 +493,14 @@ throtl_trim_slice(struct throtl_data *td, struct throtl_grp *tg, bool rw) tg->slice_start[rw] += nr_slices * throtl_slice; - throtl_log_tg(td, tg, "[%c] trim slice nr=%lu bytes=%llu io=%lu" + throtl_log_tg(tg, "[%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 bool tg_with_in_iops_limit(struct throtl_data *td, struct throtl_grp *tg, - struct bio *bio, unsigned long *wait) +static bool tg_with_in_iops_limit(struct throtl_grp *tg, struct bio *bio, + unsigned long *wait) { bool rw = bio_data_dir(bio); unsigned int io_allowed; @@ -548,8 +549,8 @@ static bool tg_with_in_iops_limit(struct throtl_data *td, struct throtl_grp *tg, return 0; } -static bool tg_with_in_bps_limit(struct throtl_data *td, struct throtl_grp *tg, - struct bio *bio, unsigned long *wait) +static bool tg_with_in_bps_limit(struct throtl_grp *tg, struct bio *bio, + unsigned long *wait) { bool rw = bio_data_dir(bio); u64 bytes_allowed, extra_bytes, tmp; @@ -600,8 +601,8 @@ static bool tg_no_rule_group(struct throtl_grp *tg, bool rw) { * Returns whether one can dispatch a bio or not. Also returns approx number * of jiffies to wait before this bio is with-in IO rate and can be dispatched */ -static bool tg_may_dispatch(struct throtl_data *td, struct throtl_grp *tg, - struct bio *bio, unsigned long *wait) +static bool tg_may_dispatch(struct throtl_grp *tg, struct bio *bio, + unsigned long *wait) { bool rw = bio_data_dir(bio); unsigned long bps_wait = 0, iops_wait = 0, max_wait = 0; @@ -626,15 +627,15 @@ static bool tg_may_dispatch(struct throtl_data *td, struct throtl_grp *tg, * existing slice to make sure it is at least throtl_slice interval * long since now. */ - if (throtl_slice_used(td, tg, rw)) - throtl_start_new_slice(td, tg, rw); + if (throtl_slice_used(tg, rw)) + throtl_start_new_slice(tg, rw); else { if (time_before(tg->slice_end[rw], jiffies + throtl_slice)) - throtl_extend_slice(td, tg, rw, jiffies + throtl_slice); + throtl_extend_slice(tg, rw, jiffies + throtl_slice); } - if (tg_with_in_bps_limit(td, tg, bio, &bps_wait) - && tg_with_in_iops_limit(td, tg, bio, &iops_wait)) { + if (tg_with_in_bps_limit(tg, bio, &bps_wait) && + tg_with_in_iops_limit(tg, bio, &iops_wait)) { if (wait) *wait = 0; return 1; @@ -646,7 +647,7 @@ static bool tg_may_dispatch(struct throtl_data *td, struct throtl_grp *tg, *wait = max_wait; if (time_before(tg->slice_end[rw], jiffies + max_wait)) - throtl_extend_slice(td, tg, rw, jiffies + max_wait); + throtl_extend_slice(tg, rw, jiffies + max_wait); return 0; } @@ -707,10 +708,10 @@ static void tg_update_disptime(struct throtl_data *td, struct throtl_grp *tg) struct bio *bio; if ((bio = bio_list_peek(&tg->bio_lists[READ]))) - tg_may_dispatch(td, tg, bio, &read_wait); + tg_may_dispatch(tg, bio, &read_wait); if ((bio = bio_list_peek(&tg->bio_lists[WRITE]))) - tg_may_dispatch(td, tg, bio, &write_wait); + tg_may_dispatch(tg, bio, &write_wait); min_wait = min(read_wait, write_wait); disptime = jiffies + min_wait; @@ -721,8 +722,8 @@ static void tg_update_disptime(struct throtl_data *td, struct throtl_grp *tg) throtl_enqueue_tg(td, tg); } -static void tg_dispatch_one_bio(struct throtl_data *td, struct throtl_grp *tg, - bool rw, struct bio_list *bl) +static void tg_dispatch_one_bio(struct throtl_grp *tg, bool rw, + struct bio_list *bl) { struct bio *bio; @@ -731,18 +732,17 @@ static void tg_dispatch_one_bio(struct throtl_data *td, struct throtl_grp *tg, /* Drop bio reference on blkg */ blkg_put(tg_to_blkg(tg)); - BUG_ON(td->nr_queued[rw] <= 0); - td->nr_queued[rw]--; + BUG_ON(tg->td->nr_queued[rw] <= 0); + tg->td->nr_queued[rw]--; throtl_charge_bio(tg, bio); bio_list_add(bl, bio); bio->bi_rw |= REQ_THROTTLED; - throtl_trim_slice(td, tg, rw); + throtl_trim_slice(tg, rw); } -static int throtl_dispatch_tg(struct throtl_data *td, struct throtl_grp *tg, - struct bio_list *bl) +static int throtl_dispatch_tg(struct throtl_grp *tg, struct bio_list *bl) { unsigned int nr_reads = 0, nr_writes = 0; unsigned int max_nr_reads = throtl_grp_quantum*3/4; @@ -751,20 +751,20 @@ static int throtl_dispatch_tg(struct throtl_data *td, struct throtl_grp *tg, /* Try to dispatch 75% READS and 25% WRITES */ - while ((bio = bio_list_peek(&tg->bio_lists[READ])) - && tg_may_dispatch(td, tg, bio, NULL)) { + while ((bio = bio_list_peek(&tg->bio_lists[READ])) && + tg_may_dispatch(tg, bio, NULL)) { - tg_dispatch_one_bio(td, tg, bio_data_dir(bio), bl); + tg_dispatch_one_bio(tg, bio_data_dir(bio), bl); nr_reads++; if (nr_reads >= max_nr_reads) break; } - while ((bio = bio_list_peek(&tg->bio_lists[WRITE])) - && tg_may_dispatch(td, tg, bio, NULL)) { + while ((bio = bio_list_peek(&tg->bio_lists[WRITE])) && + tg_may_dispatch(tg, bio, NULL)) { - tg_dispatch_one_bio(td, tg, bio_data_dir(bio), bl); + tg_dispatch_one_bio(tg, bio_data_dir(bio), bl); nr_writes++; if (nr_writes >= max_nr_writes) @@ -791,7 +791,7 @@ static int throtl_select_dispatch(struct throtl_data *td, struct bio_list *bl) throtl_dequeue_tg(td, tg); - nr_disp += throtl_dispatch_tg(td, tg, bl); + nr_disp += throtl_dispatch_tg(tg, bl); if (tg->nr_queued[0] || tg->nr_queued[1]) tg_update_disptime(td, tg); @@ -933,7 +933,7 @@ static int tg_set_conf(struct cgroup *cgrp, struct cftype *cft, const char *buf, else *(unsigned int *)((void *)tg + cft->private) = ctx.v; - throtl_log_tg(td, tg, "limit change rbps=%llu wbps=%llu riops=%u wiops=%u", + throtl_log_tg(tg, "limit change rbps=%llu wbps=%llu riops=%u wiops=%u", tg->bps[READ], tg->bps[WRITE], tg->iops[READ], tg->iops[WRITE]); @@ -945,8 +945,8 @@ static int tg_set_conf(struct cgroup *cgrp, struct cftype *cft, const char *buf, * that a group's limit are dropped suddenly and we don't want to * account recently dispatched IO with new low rate. */ - throtl_start_new_slice(td, tg, 0); - throtl_start_new_slice(td, tg, 1); + throtl_start_new_slice(tg, 0); + throtl_start_new_slice(tg, 1); if (tg->flags & THROTL_TG_PENDING) { tg_update_disptime(td, tg); @@ -1076,7 +1076,7 @@ bool blk_throtl_bio(struct request_queue *q, struct bio *bio) } /* Bio is with-in rate limit of group */ - if (tg_may_dispatch(td, tg, bio, NULL)) { + if (tg_may_dispatch(tg, bio, NULL)) { throtl_charge_bio(tg, bio); /* @@ -1090,12 +1090,12 @@ bool blk_throtl_bio(struct request_queue *q, struct bio *bio) * * So keep on trimming slice even if bio is not queued. */ - throtl_trim_slice(td, tg, rw); + throtl_trim_slice(tg, rw); goto out_unlock; } queue_bio: - throtl_log_tg(td, tg, "[%c] bio. bdisp=%llu sz=%u bps=%llu" + throtl_log_tg(tg, "[%c] bio. bdisp=%llu sz=%u bps=%llu" " iodisp=%u iops=%u queued=%d/%d", rw == READ ? 'R' : 'W', tg->bytes_disp[rw], bio->bi_size, tg->bps[rw], @@ -1142,9 +1142,9 @@ void blk_throtl_drain(struct request_queue *q) throtl_dequeue_tg(td, tg); while ((bio = bio_list_peek(&tg->bio_lists[READ]))) - tg_dispatch_one_bio(td, tg, bio_data_dir(bio), &bl); + tg_dispatch_one_bio(tg, bio_data_dir(bio), &bl); while ((bio = bio_list_peek(&tg->bio_lists[WRITE]))) - tg_dispatch_one_bio(td, tg, bio_data_dir(bio), &bl); + tg_dispatch_one_bio(tg, bio_data_dir(bio), &bl); } spin_unlock_irq(q->queue_lock);