From 41b38b6d540f951c49315d8573e6f6195a6e736d Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Sun, 1 Apr 2012 14:38:44 -0700 Subject: blkcg: cfq doesn't need per-cpu dispatch stats blkio_group_stats_cpu is used to count dispatch stats using per-cpu counters. This is used by both blk-throtl and cfq-iosched but the sharing is rather silly. * cfq-iosched doesn't need per-cpu dispatch stats. cfq always updates those stats while holding queue_lock. * blk-throtl needs per-cpu dispatch stats but only service_bytes and serviced. It doesn't make use of sectors. This patch makes cfq add and use global stats for service_bytes, serviced and sectors, removes per-cpu sectors counter and moves per-cpu stat printing code to blk-throttle.c. Signed-off-by: Tejun Heo --- block/cfq-iosched.c | 37 ++++++++++--------------------------- 1 file changed, 10 insertions(+), 27 deletions(-) (limited to 'block/cfq-iosched.c') diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c index 4991380..effd894 100644 --- a/block/cfq-iosched.c +++ b/block/cfq-iosched.c @@ -624,29 +624,12 @@ static inline void cfq_blkiocg_update_dispatch_stats(struct blkio_group *blkg, struct blkio_policy_type *pol, uint64_t bytes, bool direction, bool sync) { + struct blkio_group_stats *stats = &blkg->pd[pol->plid]->stats; int rw = (direction ? REQ_WRITE : 0) | (sync ? REQ_SYNC : 0); - struct blkg_policy_data *pd = blkg->pd[pol->plid]; - struct blkio_group_stats_cpu *stats_cpu; - unsigned long flags; - /* If per cpu stats are not allocated yet, don't do any accounting. */ - if (pd->stats_cpu == NULL) - return; - - /* - * Disabling interrupts to provide mutual exclusion between two - * writes on same cpu. It probably is not needed for 64bit. Not - * optimizing that case yet. - */ - local_irq_save(flags); - - stats_cpu = this_cpu_ptr(pd->stats_cpu); - - blkg_stat_add(&stats_cpu->sectors, bytes >> 9); - blkg_rwstat_add(&stats_cpu->serviced, rw, 1); - blkg_rwstat_add(&stats_cpu->service_bytes, rw, bytes); - - local_irq_restore(flags); + blkg_stat_add(&stats->sectors, bytes >> 9); + blkg_rwstat_add(&stats->serviced, rw, 1); + blkg_rwstat_add(&stats->service_bytes, rw, bytes); } static inline void cfq_blkiocg_update_completion_stats(struct blkio_group *blkg, @@ -1520,20 +1503,20 @@ static struct cftype cfq_blkcg_files[] = { { .name = "sectors", .private = BLKCG_STAT_PRIV(BLKIO_POLICY_PROP, - offsetof(struct blkio_group_stats_cpu, sectors)), - .read_seq_string = blkcg_print_cpu_stat, + offsetof(struct blkio_group_stats, sectors)), + .read_seq_string = blkcg_print_stat, }, { .name = "io_service_bytes", .private = BLKCG_STAT_PRIV(BLKIO_POLICY_PROP, - offsetof(struct blkio_group_stats_cpu, service_bytes)), - .read_seq_string = blkcg_print_cpu_rwstat, + offsetof(struct blkio_group_stats, service_bytes)), + .read_seq_string = blkcg_print_rwstat, }, { .name = "io_serviced", .private = BLKCG_STAT_PRIV(BLKIO_POLICY_PROP, - offsetof(struct blkio_group_stats_cpu, serviced)), - .read_seq_string = blkcg_print_cpu_rwstat, + offsetof(struct blkio_group_stats, serviced)), + .read_seq_string = blkcg_print_rwstat, }, { .name = "io_service_time", -- cgit v1.1