Messages in this thread Patch in this message | | | From | Robin Dong <> | Subject | [PATCH 2/2 v5] block/throttle: Add IO submitted information in blkio.throttle | Date | Fri, 2 Nov 2012 17:31:37 +0800 |
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From: Robin Dong <sanbai@taobao.com>
Currently, if the IO is throttled by io-throttle, the system admin has no idea of the situation and can't report it to the real application user about that he/she has to do something.
So this patch adds a new interface named blkio.throttle.io_submitted which exposes the number of bios that have been sent into blk-throttle therefore the user could calculate the difference from throttle.io_serviced to see how many IOs are currently throttled.
Cc: Tejun Heo <tj@kernel.org> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: Jens Axboe <axboe@kernel.dk> Signed-off-by: Tao Ma <boyu.mt@taobao.com> Signed-off-by: Robin Dong <sanbai@taobao.com> --- v3 <-- v2: - Use nr-queued[] of struct throtl_grp for stats instaed of adding new blkg_rwstat.
v4 <-- v3: - Add two new blkg_rwstat arguments to count total bios be sent into blk_throttle.
v5 <-- v4: - Change name "io_submit_bytes" to "io_submitted_bytes".
block/blk-throttle.c | 43 +++++++++++++++++++++++++++++++++++++++++++ 1 files changed, 43 insertions(+), 0 deletions(-)
diff --git a/block/blk-throttle.c b/block/blk-throttle.c index 46ddeff..c6391b5 100644 --- a/block/blk-throttle.c +++ b/block/blk-throttle.c @@ -46,6 +46,10 @@ struct tg_stats_cpu { struct blkg_rwstat service_bytes; /* total IOs serviced, post merge */ struct blkg_rwstat serviced; + /* total bytes submitted into blk-throttle */ + struct blkg_rwstat submit_bytes; + /* total IOs submitted into blk-throttle */ + struct blkg_rwstat submitted; }; struct throtl_grp { @@ -266,6 +270,8 @@ static void throtl_pd_reset_stats(struct blkcg_gq *blkg) blkg_rwstat_reset(&sc->service_bytes); blkg_rwstat_reset(&sc->serviced); + blkg_rwstat_reset(&sc->submit_bytes); + blkg_rwstat_reset(&sc->submitted); } } @@ -699,6 +705,30 @@ static void throtl_update_dispatch_stats(struct throtl_grp *tg, u64 bytes, local_irq_restore(flags); } +static void throtl_update_submit_stats(struct throtl_grp *tg, u64 bytes, int rw) +{ + struct tg_stats_cpu *stats_cpu; + unsigned long flags; + + /* If per cpu stats are not allocated yet, don't do any accounting. */ + if (tg->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(tg->stats_cpu); + + blkg_rwstat_add(&stats_cpu->submitted, rw, 1); + blkg_rwstat_add(&stats_cpu->submit_bytes, rw, bytes); + + local_irq_restore(flags); +} + static void throtl_charge_bio(struct throtl_grp *tg, struct bio *bio) { bool rw = bio_data_dir(bio); @@ -1084,6 +1114,16 @@ static struct cftype throtl_files[] = { .private = offsetof(struct tg_stats_cpu, serviced), .read_seq_string = tg_print_cpu_rwstat, }, + { + .name = "throttle.io_submitted_bytes", + .private = offsetof(struct tg_stats_cpu, submit_bytes), + .read_seq_string = tg_print_cpu_rwstat, + }, + { + .name = "throttle.io_submitted", + .private = offsetof(struct tg_stats_cpu, submitted), + .read_seq_string = tg_print_cpu_rwstat, + }, { } /* terminate */ }; @@ -1128,6 +1168,8 @@ bool blk_throtl_bio(struct request_queue *q, struct bio *bio) if (tg_no_rule_group(tg, rw)) { throtl_update_dispatch_stats(tg, bio->bi_size, bio->bi_rw); + throtl_update_submit_stats(tg, + bio->bi_size, bio->bi_rw); goto out_unlock_rcu; } } @@ -1141,6 +1183,7 @@ bool blk_throtl_bio(struct request_queue *q, struct bio *bio) if (unlikely(!tg)) goto out_unlock; + throtl_update_submit_stats(tg, bio->bi_size, bio->bi_rw); if (tg->nr_queued[rw]) { /* * There is already another bio queued in same dir. No -- 1.7.1
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