Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751953AbcDWIVz (ORCPT ); Sat, 23 Apr 2016 04:21:55 -0400 Received: from szxga03-in.huawei.com ([119.145.14.66]:3348 "EHLO szxga03-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751742AbcDWIVw (ORCPT ); Sat, 23 Apr 2016 04:21:52 -0400 Message-ID: <571B3073.2010206@huawei.com> Date: Sat, 23 Apr 2016 16:21:07 +0800 From: xiakaixu User-Agent: Mozilla/5.0 (Windows NT 6.1; rv:17.0) Gecko/20130801 Thunderbird/17.0.8 MIME-Version: 1.0 To: Jens Axboe CC: , , , , , "miaoxie (A)" , Bintian , Huxinwei , Xia Kaixu Subject: Re: [PATCH 8/8] writeback: throttle buffered writeback References: <1460953487-3430-1-git-send-email-axboe@fb.com> <1460953487-3430-9-git-send-email-axboe@fb.com> In-Reply-To: <1460953487-3430-9-git-send-email-axboe@fb.com> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.111.101.23] X-CFilter-Loop: Reflected X-Mirapoint-Virus-RAPID-Raw: score=unknown(0), refid=str=0001.0A020205.571B3086.0006,ss=1,re=0.000,recu=0.000,reip=0.000,cl=1,cld=1,fgs=0, ip=0.0.0.0, so=2013-05-26 15:14:31, dmn=2013-03-21 17:37:32 X-Mirapoint-Loop-Id: dc841e9e25f50e20403938222cdb44c7 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 6012 Lines: 202 > diff --git a/block/blk-core.c b/block/blk-core.c > index 40b57bf4852c..d941f69dfb4b 100644 > --- a/block/blk-core.c > +++ b/block/blk-core.c > @@ -39,6 +39,7 @@ > > #include "blk.h" > #include "blk-mq.h" > +#include "blk-wb.h" > > EXPORT_TRACEPOINT_SYMBOL_GPL(block_bio_remap); > EXPORT_TRACEPOINT_SYMBOL_GPL(block_rq_remap); > @@ -880,6 +881,7 @@ blk_init_allocated_queue(struct request_queue *q, request_fn_proc *rfn, > > fail: > blk_free_flush_queue(q->fq); > + blk_wb_exit(q); > return NULL; > } > EXPORT_SYMBOL(blk_init_allocated_queue); > @@ -1395,6 +1397,7 @@ void blk_requeue_request(struct request_queue *q, struct request *rq) > blk_delete_timer(rq); > blk_clear_rq_complete(rq); > trace_block_rq_requeue(q, rq); > + blk_wb_requeue(q->rq_wb, rq); > > if (rq->cmd_flags & REQ_QUEUED) > blk_queue_end_tag(q, rq); > @@ -1485,6 +1488,8 @@ void __blk_put_request(struct request_queue *q, struct request *req) > /* this is a bio leak */ > WARN_ON(req->bio != NULL); > > + blk_wb_done(q->rq_wb, req); > + > /* > * Request may not have originated from ll_rw_blk. if not, > * it didn't come out of our reserved rq pools > @@ -1714,6 +1719,7 @@ static blk_qc_t blk_queue_bio(struct request_queue *q, struct bio *bio) > int el_ret, rw_flags, where = ELEVATOR_INSERT_SORT; > struct request *req; > unsigned int request_count = 0; > + bool wb_acct; > > /* > * low level driver can indicate that it wants pages above a > @@ -1766,6 +1772,8 @@ static blk_qc_t blk_queue_bio(struct request_queue *q, struct bio *bio) > } > > get_rq: > + wb_acct = blk_wb_wait(q->rq_wb, bio, q->queue_lock); > + > /* > * This sync check and mask will be re-done in init_request_from_bio(), > * but we need to set it earlier to expose the sync flag to the > @@ -1781,11 +1789,16 @@ get_rq: > */ > req = get_request(q, rw_flags, bio, GFP_NOIO); > if (IS_ERR(req)) { > + if (wb_acct) > + __blk_wb_done(q->rq_wb); > bio->bi_error = PTR_ERR(req); > bio_endio(bio); > goto out_unlock; > } > > + if (wb_acct) > + req->cmd_flags |= REQ_BUF_INFLIGHT; > + > /* > * After dropping the lock and possibly sleeping here, our request > * may now be mergeable after it had proven unmergeable (above). > @@ -2515,6 +2528,7 @@ void blk_start_request(struct request *req) > blk_dequeue_request(req); > > req->issue_time = ktime_to_ns(ktime_get()); > + blk_wb_issue(req->q->rq_wb, req); > > /* > * We are now handing the request to the hardware, initialize > @@ -2751,6 +2765,7 @@ void blk_finish_request(struct request *req, int error) > blk_unprep_request(req); > > blk_account_io_done(req); > + blk_wb_done(req->q->rq_wb, req); Hi Jens, Seems the function blk_wb_done() will be executed twice even if the end_io callback is set. Maybe the same thing would happen in blk-mq.c. > > if (req->end_io) > req->end_io(req, error); > diff --git a/block/blk-mq.c b/block/blk-mq.c > index 71b4a13fbf94..c0c5207fe7fd 100644 > --- a/block/blk-mq.c > +++ b/block/blk-mq.c > @@ -30,6 +30,7 @@ > #include "blk-mq.h" > #include "blk-mq-tag.h" > #include "blk-stat.h" > +#include "blk-wb.h" > > static DEFINE_MUTEX(all_q_mutex); > static LIST_HEAD(all_q_list); > @@ -275,6 +276,9 @@ static void __blk_mq_free_request(struct blk_mq_hw_ctx *hctx, > > if (rq->cmd_flags & REQ_MQ_INFLIGHT) > atomic_dec(&hctx->nr_active); > + > + blk_wb_done(q->rq_wb, rq); > + > rq->cmd_flags = 0; > > clear_bit(REQ_ATOM_STARTED, &rq->atomic_flags); > @@ -305,6 +309,7 @@ EXPORT_SYMBOL_GPL(blk_mq_free_request); > inline void __blk_mq_end_request(struct request *rq, int error) > { > blk_account_io_done(rq); > + blk_wb_done(rq->q->rq_wb, rq); > > if (rq->end_io) { > rq->end_io(rq, error); > @@ -414,6 +419,7 @@ void blk_mq_start_request(struct request *rq) > rq->next_rq->resid_len = blk_rq_bytes(rq->next_rq); > > rq->issue_time = ktime_to_ns(ktime_get()); > + blk_wb_issue(q->rq_wb, rq); > > blk_add_timer(rq); > > @@ -450,6 +456,7 @@ static void __blk_mq_requeue_request(struct request *rq) > struct request_queue *q = rq->q; > > trace_block_rq_requeue(q, rq); > + blk_wb_requeue(q->rq_wb, rq); > > if (test_and_clear_bit(REQ_ATOM_STARTED, &rq->atomic_flags)) { > if (q->dma_drain_size && blk_rq_bytes(rq)) > @@ -1265,6 +1272,7 @@ static blk_qc_t blk_mq_make_request(struct request_queue *q, struct bio *bio) > struct blk_plug *plug; > struct request *same_queue_rq = NULL; > blk_qc_t cookie; > + bool wb_acct; > > blk_queue_bounce(q, &bio); > > @@ -1282,9 +1290,17 @@ static blk_qc_t blk_mq_make_request(struct request_queue *q, struct bio *bio) > } else > request_count = blk_plug_queued_count(q); > > + wb_acct = blk_wb_wait(q->rq_wb, bio, NULL); > + > rq = blk_mq_map_request(q, bio, &data); > - if (unlikely(!rq)) > + if (unlikely(!rq)) { > + if (wb_acct) > + __blk_wb_done(q->rq_wb); > return BLK_QC_T_NONE; > + } > + > + if (wb_acct) > + rq->cmd_flags |= REQ_BUF_INFLIGHT; > > cookie = blk_tag_to_qc_t(rq->tag, data.hctx->queue_num); > > @@ -1361,6 +1377,7 @@ static blk_qc_t blk_sq_make_request(struct request_queue *q, struct bio *bio) > struct blk_map_ctx data; > struct request *rq; > blk_qc_t cookie; > + bool wb_acct; > > blk_queue_bounce(q, &bio); > > @@ -1375,9 +1392,17 @@ static blk_qc_t blk_sq_make_request(struct request_queue *q, struct bio *bio) > blk_attempt_plug_merge(q, bio, &request_count, NULL)) > return BLK_QC_T_NONE; > > + wb_acct = blk_wb_wait(q->rq_wb, bio, NULL); > + > rq = blk_mq_map_request(q, bio, &data); > - if (unlikely(!rq)) > + if (unlikely(!rq)) { > + if (wb_acct) > + __blk_wb_done(q->rq_wb); > return BLK_QC_T_NONE; > + } > + > + if (wb_acct) > + rq->cmd_flags |= REQ_BUF_INFLIGHT; > > cookie = blk_tag_to_qc_t(rq->tag, data.hctx->queue_num); > > @@ -2111,6 +2136,8 @@ void blk_mq_free_queue(struct request_queue *q) > list_del_init(&q->all_q_node); -- Regards Kaixu Xia