From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tejun Heo Subject: [PATCH 6/7] blkcg: account requests instead of bios for request based request_queues Date: Sun, 12 Nov 2017 14:26:12 -0800 Message-ID: <20171112222613.3613362-7-tj@kernel.org> References: <20171112222613.3613362-1-tj@kernel.org> Return-path: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=sender:from:to:cc:subject:date:message-id:in-reply-to:references; bh=KzEP2r7HKUFZsx/KBh9pVeUjTtngSwnI6y9v2XYkusw=; b=vD5ro/KiPL9wdN2AtQTBKUUKzEXkM/kWA14guhpwLr7bEdMii12pAVgfmLOGsMpdWZ 38np32sNTHfBgKwuhwTa8wqJRXIcjEmmGE429mrtVlUjCz7pfIdwmf+vp7EMeuYfDl4z ritgCPY8LzarWTnBzFWzNodWPeWRSwUm/N7iIGhs2CP5WzwC4aoxW2OtsQHLRbe0dRkl wnAKIfHvG73sLfRL5QQSJJCSYmGCL1Y/8VOLXx9fZsTDpbNDn9OTQckXr4Ozcx9pnb9F cooaIeL7nauwH4Zwk2SWDJsU54fsMswHP9XPTrMiYgrfNeHD7EX5rSnytt3987W7MA3D eoHA== In-Reply-To: <20171112222613.3613362-1-tj@kernel.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: axboe@kernel.dk Cc: shli@kernel.org, linux-kernel@vger.kernel.org, kernel-team@fb.com, lizefan@huawei.com, hannes@cmpxchg.org, cgroups@vger.kernel.org, guro@fb.com, Tejun Heo blkcg accounting is currently bio based, which is silly for request based request_queues. This is silly as the number of bios doesn't have much to do with the actual number of IOs issued to the underlying device (can be significantly higher or lower) and may change depending on the implementation details on how the bios are issued (e.g. from the recent split-bios-while-issuing change). request based request_queues have QUEUE_FLAG_IO_STAT set by default which controls the gendisk accounting. Do cgroup accounting for those request_queues together with gendisk accounting on request completion. This makes cgroup accounting consistent with gendisk accounting and what's happening on the system. Signed-off-by: Tejun Heo --- block/blk-core.c | 3 +++ include/linux/blk-cgroup.h | 18 +++++++++++++++++- 2 files changed, 20 insertions(+), 1 deletion(-) diff --git a/block/blk-core.c b/block/blk-core.c index 048be4a..ad23b96 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -2429,6 +2429,7 @@ void blk_account_io_completion(struct request *req, unsigned int bytes) cpu = part_stat_lock(); part = req->part; part_stat_add(cpu, part, sectors[rw], bytes >> 9); + blkcg_account_io_completion(req, bytes); part_stat_unlock(); } } @@ -2454,6 +2455,8 @@ void blk_account_io_done(struct request *req) part_round_stats(req->q, cpu, part); part_dec_in_flight(req->q, part, rw); + blkcg_account_io_done(req); + hd_struct_put(part); part_stat_unlock(); } diff --git a/include/linux/blk-cgroup.h b/include/linux/blk-cgroup.h index 96eed0f..f2f9691 100644 --- a/include/linux/blk-cgroup.h +++ b/include/linux/blk-cgroup.h @@ -715,7 +715,8 @@ static inline bool blkcg_bio_issue_check(struct request_queue *q, throtl = blk_throtl_bio(q, blkg, bio); - if (!throtl) { + /* if @q does io stat, blkcg stats are updated together with them */ + if (!blk_queue_io_stat(q) && !throtl) { blkg_rwstat_add(&blkg->stat_bytes, bio->bi_opf, bio->bi_iter.bi_size); blkg_rwstat_add(&blkg->stat_ios, bio->bi_opf, 1); @@ -764,6 +765,17 @@ static inline void blk_rq_disassociate_blkg(struct request *rq) rq->blkg = NULL; } +static inline void blkcg_account_io_completion(struct request *rq, + unsigned int bytes) +{ + blkg_rwstat_add(&rq->blkg->stat_bytes, rq_data_dir(rq), bytes); +} + +static inline void blkcg_account_io_done(struct request *rq) +{ + blkg_rwstat_add(&rq->blkg->stat_ios, rq_data_dir(rq), 1); +} + #else /* CONFIG_BLK_CGROUP */ struct blkcg { @@ -823,6 +835,10 @@ static inline bool blkcg_bio_issue_check(struct request_queue *q, static inline void blk_rq_associate_blkg(struct request *rq, struct blkcg *blkcg) { } static inline void blk_rq_disassociate_blkg(struct request *rq) { } +static inline void blkcg_account_io_completion(struct request *rq, + unsigned int bytes) { } +static inline void blkcg_account_io_done(struct request *rq) { } + #define blk_queue_for_each_rl(rl, q) \ for ((rl) = &(q)->root_rl; (rl); (rl) = NULL) -- 2.9.5