From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751252AbdAMIax (ORCPT ); Fri, 13 Jan 2017 03:30:53 -0500 Received: from bombadil.infradead.org ([198.137.202.9]:42652 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751157AbdAMIaw (ORCPT ); Fri, 13 Jan 2017 03:30:52 -0500 Date: Fri, 13 Jan 2017 00:30:51 -0800 From: Christoph Hellwig To: Jens Axboe Cc: linux-kernel@vger.kernel.org, linux-block@vger.kernel.org, osandov@osandov.com, bart.vanassche@sandisk.com Subject: Re: [PATCH 06/10] blk-mq-tag: cleanup the normal/reserved tag allocation Message-ID: <20170113083051.GD637@infradead.org> References: <1484170803-9311-1-git-send-email-axboe@fb.com> <1484170803-9311-7-git-send-email-axboe@fb.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1484170803-9311-7-git-send-email-axboe@fb.com> User-Agent: Mutt/1.7.1 (2016-10-04) X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Jan 11, 2017 at 02:39:59PM -0700, Jens Axboe wrote: > This is in preparation for having another tag set available. Cleanup > the parameters, and allow passing in of tags fo blk_mq_put_tag(). I've been playing around with this are a bit but never submitted anything. Below is an untested merge of my previous bits with your patch, let me know what you think about it: --- >>From c9ea92bfb468e9116149db95d246e48ace2b87f1 Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Wed, 11 Jan 2017 11:04:53 -0700 Subject: blk-mq-tag: cleanup the normal/reserved tag allocation This is in preparation for having another tag set available. Cleanup the parameters, and allow passing in of tags for blk_mq_put_tag(). Signed-off-by: Jens Axboe [hch: even more cleanups] Signed-off-by: Christoph Hellwig --- block/blk-mq-tag.c | 94 +++++++++++++++++++++--------------------------------- block/blk-mq-tag.h | 4 +-- block/blk-mq.c | 2 +- block/blk-mq.h | 5 +++ 4 files changed, 44 insertions(+), 61 deletions(-) diff --git a/block/blk-mq-tag.c b/block/blk-mq-tag.c index dcf5ce3..ced7527 100644 --- a/block/blk-mq-tag.c +++ b/block/blk-mq-tag.c @@ -90,32 +90,46 @@ static inline bool hctx_may_queue(struct blk_mq_hw_ctx *hctx, return atomic_read(&hctx->nr_active) < depth; } -static int __bt_get(struct blk_mq_hw_ctx *hctx, struct sbitmap_queue *bt) +static int __blk_mq_get_tag(struct blk_mq_hw_ctx *hctx, struct sbitmap_queue *bt) { if (!hctx_may_queue(hctx, bt)) return -1; return __sbitmap_queue_get(bt); } -static int bt_get(struct blk_mq_alloc_data *data, struct sbitmap_queue *bt, - struct blk_mq_hw_ctx *hctx, struct blk_mq_tags *tags) +unsigned int blk_mq_get_tag(struct blk_mq_alloc_data *data) { + struct blk_mq_tags *tags = blk_mq_tags_from_data(data); + struct sbitmap_queue *bt; struct sbq_wait_state *ws; DEFINE_WAIT(wait); + unsigned int tag_offset; int tag; - tag = __bt_get(hctx, bt); + if (data->flags & BLK_MQ_REQ_RESERVED) { + if (unlikely(!tags->nr_reserved_tags)) { + WARN_ON_ONCE(1); + return BLK_MQ_TAG_FAIL; + } + bt = &tags->breserved_tags; + tag_offset = 0; + } else { + bt = &tags->bitmap_tags; + tag_offset = tags->nr_reserved_tags; + } + + tag = __blk_mq_get_tag(data->hctx, bt); if (tag != -1) - return tag; + goto found_tag; if (data->flags & BLK_MQ_REQ_NOWAIT) - return -1; + return BLK_MQ_TAG_FAIL; - ws = bt_wait_ptr(bt, hctx); + ws = bt_wait_ptr(bt, data->hctx); do { prepare_to_wait(&ws->wait, &wait, TASK_UNINTERRUPTIBLE); - tag = __bt_get(hctx, bt); + tag = __blk_mq_get_tag(data->hctx, bt); if (tag != -1) break; @@ -125,14 +139,14 @@ static int bt_get(struct blk_mq_alloc_data *data, struct sbitmap_queue *bt, * some to complete. Note that hctx can be NULL here for * reserved tag allocation. */ - if (hctx) - blk_mq_run_hw_queue(hctx, false); + if (data->hctx) + blk_mq_run_hw_queue(data->hctx, false); /* * Retry tag allocation after running the hardware queue, * as running the queue may also have found completions. */ - tag = __bt_get(hctx, bt); + tag = __blk_mq_get_tag(data->hctx, bt); if (tag != -1) break; @@ -142,61 +156,25 @@ static int bt_get(struct blk_mq_alloc_data *data, struct sbitmap_queue *bt, data->ctx = blk_mq_get_ctx(data->q); data->hctx = blk_mq_map_queue(data->q, data->ctx->cpu); - if (data->flags & BLK_MQ_REQ_RESERVED) { - bt = &data->hctx->tags->breserved_tags; - } else { - hctx = data->hctx; - bt = &hctx->tags->bitmap_tags; - } + tags = blk_mq_tags_from_data(data); + if (data->flags & BLK_MQ_REQ_RESERVED) + bt = &tags->breserved_tags; + else + bt = &tags->bitmap_tags; + finish_wait(&ws->wait, &wait); - ws = bt_wait_ptr(bt, hctx); + ws = bt_wait_ptr(bt, data->hctx); } while (1); finish_wait(&ws->wait, &wait); - return tag; -} - -static unsigned int __blk_mq_get_tag(struct blk_mq_alloc_data *data) -{ - int tag; - - tag = bt_get(data, &data->hctx->tags->bitmap_tags, data->hctx, - data->hctx->tags); - if (tag >= 0) - return tag + data->hctx->tags->nr_reserved_tags; - - return BLK_MQ_TAG_FAIL; -} - -static unsigned int __blk_mq_get_reserved_tag(struct blk_mq_alloc_data *data) -{ - int tag; - if (unlikely(!data->hctx->tags->nr_reserved_tags)) { - WARN_ON_ONCE(1); - return BLK_MQ_TAG_FAIL; - } - - tag = bt_get(data, &data->hctx->tags->breserved_tags, NULL, - data->hctx->tags); - if (tag < 0) - return BLK_MQ_TAG_FAIL; - - return tag; +found_tag: + return tag + tag_offset; } -unsigned int blk_mq_get_tag(struct blk_mq_alloc_data *data) +void blk_mq_put_tag(struct blk_mq_hw_ctx *hctx, struct blk_mq_tags *tags, + struct blk_mq_ctx *ctx, unsigned int tag) { - if (data->flags & BLK_MQ_REQ_RESERVED) - return __blk_mq_get_reserved_tag(data); - return __blk_mq_get_tag(data); -} - -void blk_mq_put_tag(struct blk_mq_hw_ctx *hctx, struct blk_mq_ctx *ctx, - unsigned int tag) -{ - struct blk_mq_tags *tags = hctx->tags; - if (tag >= tags->nr_reserved_tags) { const int real_tag = tag - tags->nr_reserved_tags; diff --git a/block/blk-mq-tag.h b/block/blk-mq-tag.h index d166273..923602d 100644 --- a/block/blk-mq-tag.h +++ b/block/blk-mq-tag.h @@ -24,8 +24,8 @@ extern struct blk_mq_tags *blk_mq_init_tags(unsigned int nr_tags, unsigned int r extern void blk_mq_free_tags(struct blk_mq_tags *tags); extern unsigned int blk_mq_get_tag(struct blk_mq_alloc_data *data); -extern void blk_mq_put_tag(struct blk_mq_hw_ctx *hctx, struct blk_mq_ctx *ctx, - unsigned int tag); +extern void blk_mq_put_tag(struct blk_mq_hw_ctx *hctx, struct blk_mq_tags *tags, + struct blk_mq_ctx *ctx, unsigned int tag); extern bool blk_mq_has_free_tags(struct blk_mq_tags *tags); extern ssize_t blk_mq_tag_sysfs_show(struct blk_mq_tags *tags, char *page); extern int blk_mq_tag_update_depth(struct blk_mq_tags *tags, unsigned int depth); diff --git a/block/blk-mq.c b/block/blk-mq.c index 9fc5217..6fab8e9 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -335,7 +335,7 @@ void __blk_mq_free_request(struct blk_mq_hw_ctx *hctx, struct blk_mq_ctx *ctx, clear_bit(REQ_ATOM_STARTED, &rq->atomic_flags); clear_bit(REQ_ATOM_POLL_SLEPT, &rq->atomic_flags); - blk_mq_put_tag(hctx, ctx, tag); + blk_mq_put_tag(hctx, hctx->tags, ctx, tag); blk_queue_exit(q); } diff --git a/block/blk-mq.h b/block/blk-mq.h index e59f5ca..48b7771 100644 --- a/block/blk-mq.h +++ b/block/blk-mq.h @@ -118,6 +118,11 @@ static inline void blk_mq_set_alloc_data(struct blk_mq_alloc_data *data, data->hctx = hctx; } +static inline struct blk_mq_tags *blk_mq_tags_from_data(struct blk_mq_alloc_data *data) +{ + return data->hctx->tags; +} + /* * Internal helpers for request allocation/init/free */ -- 2.1.4