From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Hannes Reinecke To: Jens Axboe Cc: Omar Sandoval , "Martin K. Petersen" , James Bottomley , Christoph Hellwig , Bart van Assche , linux-block@vger.kernel.org, linux-scsi@vger.kernel.org, Hannes Reinecke , Hannes Reinecke Subject: [PATCH 1/2] block: Implement global tagset Date: Tue, 4 Apr 2017 14:07:44 +0200 Message-Id: <1491307665-47656-2-git-send-email-hare@suse.de> In-Reply-To: <1491307665-47656-1-git-send-email-hare@suse.de> References: <1491307665-47656-1-git-send-email-hare@suse.de> List-ID: Most legacy HBAs have a tagset per HBA, not per queue. To map these devices onto block-mq this patch implements a new tagset flag BLK_MQ_F_GLOBAL_TAGS, which will cause the tag allocator to use just one tagset for all hardware queues. Signed-off-by: Hannes Reinecke --- block/blk-mq-tag.c | 12 ++++++++---- block/blk-mq.c | 10 ++++++++-- include/linux/blk-mq.h | 1 + 3 files changed, 17 insertions(+), 6 deletions(-) diff --git a/block/blk-mq-tag.c b/block/blk-mq-tag.c index e48bc2c..a14e76c 100644 --- a/block/blk-mq-tag.c +++ b/block/blk-mq-tag.c @@ -276,9 +276,11 @@ static void blk_mq_all_tag_busy_iter(struct blk_mq_tags *tags, void blk_mq_tagset_busy_iter(struct blk_mq_tag_set *tagset, busy_tag_iter_fn *fn, void *priv) { - int i; + int i, lim = tagset->nr_hw_queues; - for (i = 0; i < tagset->nr_hw_queues; i++) { + if (tagset->flags & BLK_MQ_F_GLOBAL_TAGS) + lim = 1; + for (i = 0; i < lim; i++) { if (tagset->tags && tagset->tags[i]) blk_mq_all_tag_busy_iter(tagset->tags[i], fn, priv); } @@ -287,12 +289,14 @@ void blk_mq_tagset_busy_iter(struct blk_mq_tag_set *tagset, int blk_mq_reinit_tagset(struct blk_mq_tag_set *set) { - int i, j, ret = 0; + int i, j, ret = 0, lim = set->nr_hw_queues; if (!set->ops->reinit_request) goto out; - for (i = 0; i < set->nr_hw_queues; i++) { + if (set->flags & BLK_MQ_F_GLOBAL_TAGS) + lim = 1; + for (i = 0; i < lim; i++) { struct blk_mq_tags *tags = set->tags[i]; for (j = 0; j < tags->nr_tags; j++) { diff --git a/block/blk-mq.c b/block/blk-mq.c index 159187a..db96ed0 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -2061,6 +2061,10 @@ static bool __blk_mq_alloc_rq_map(struct blk_mq_tag_set *set, int hctx_idx) { int ret = 0; + if ((set->flags & BLK_MQ_F_GLOBAL_TAGS) && hctx_idx != 0) { + set->tags[hctx_idx] = set->tags[0]; + return true; + } set->tags[hctx_idx] = blk_mq_alloc_rq_map(set, hctx_idx, set->queue_depth, set->reserved_tags); if (!set->tags[hctx_idx]) @@ -2080,8 +2084,10 @@ static void blk_mq_free_map_and_requests(struct blk_mq_tag_set *set, unsigned int hctx_idx) { if (set->tags[hctx_idx]) { - blk_mq_free_rqs(set, set->tags[hctx_idx], hctx_idx); - blk_mq_free_rq_map(set->tags[hctx_idx]); + if (!(set->flags & BLK_MQ_F_GLOBAL_TAGS) || hctx_idx == 0) { + blk_mq_free_rqs(set, set->tags[hctx_idx], hctx_idx); + blk_mq_free_rq_map(set->tags[hctx_idx]); + } set->tags[hctx_idx] = NULL; } } diff --git a/include/linux/blk-mq.h b/include/linux/blk-mq.h index b296a90..eee27b016 100644 --- a/include/linux/blk-mq.h +++ b/include/linux/blk-mq.h @@ -155,6 +155,7 @@ enum { BLK_MQ_F_DEFER_ISSUE = 1 << 4, BLK_MQ_F_BLOCKING = 1 << 5, BLK_MQ_F_NO_SCHED = 1 << 6, + BLK_MQ_F_GLOBAL_TAGS = 1 << 7, BLK_MQ_F_ALLOC_POLICY_START_BIT = 8, BLK_MQ_F_ALLOC_POLICY_BITS = 1, -- 1.8.5.6