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From: Jens Axboe <axboe@kernel.dk>
To: linux-block@vger.kernel.org, linux-nvme@lists.infradead.org,
	linux-kernel@vger.kernel.org
Cc: Jens Axboe <axboe@kernel.dk>
Subject: [PATCH 11/16] blk-mq: improve plug list sorting
Date: Tue, 30 Oct 2018 12:32:47 -0600	[thread overview]
Message-ID: <20181030183252.17857-12-axboe@kernel.dk> (raw)
In-Reply-To: <20181030183252.17857-1-axboe@kernel.dk>

Currently we only look at the software queue, but with support
for multiple maps, we should also look at the hardware queue.
This is important since we'll flush out the request list if
either the software queue or hardware queue don't match.

This sorts by software queue first, then hardware queue if
that differs. Finally we sort by request location like before.
This minimizes the flush points per plug list.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
---
 block/blk-mq.c | 17 ++++++++++++-----
 1 file changed, 12 insertions(+), 5 deletions(-)

diff --git a/block/blk-mq.c b/block/blk-mq.c
index 51b8166959b9..5a34c9374dc7 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -1611,14 +1611,21 @@ void blk_mq_insert_requests(struct blk_mq_hw_ctx *hctx, struct blk_mq_ctx *ctx,
 	spin_unlock(&ctx->lock);
 }
 
-static int plug_ctx_cmp(void *priv, struct list_head *a, struct list_head *b)
+static int plug_rq_cmp(void *priv, struct list_head *a, struct list_head *b)
 {
 	struct request *rqa = container_of(a, struct request, queuelist);
 	struct request *rqb = container_of(b, struct request, queuelist);
 
-	return !(rqa->mq_ctx < rqb->mq_ctx ||
-		 (rqa->mq_ctx == rqb->mq_ctx &&
-		  blk_rq_pos(rqa) < blk_rq_pos(rqb)));
+	if (rqa->mq_ctx < rqb->mq_ctx)
+		return -1;
+	else if (rqa->mq_ctx > rqb->mq_ctx)
+		return 1;
+	else if (rqa->mq_hctx < rqb->mq_hctx)
+		return -1;
+	else if (rqa->mq_hctx > rqb->mq_hctx)
+		return 1;
+
+	return blk_rq_pos(rqa) > blk_rq_pos(rqb);
 }
 
 void blk_mq_flush_plug_list(struct blk_plug *plug, bool from_schedule)
@@ -1633,7 +1640,7 @@ void blk_mq_flush_plug_list(struct blk_plug *plug, bool from_schedule)
 
 	list_splice_init(&plug->mq_list, &list);
 
-	list_sort(NULL, &list, plug_ctx_cmp);
+	list_sort(NULL, &list, plug_rq_cmp);
 
 	this_q = NULL;
 	this_hctx = NULL;
-- 
2.17.1


  parent reply	other threads:[~2018-10-30 18:33 UTC|newest]

Thread overview: 48+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-10-30 18:32 [PATCHSET v3 0/16] blk-mq: Add support for multiple queue maps Jens Axboe
2018-10-30 18:32 ` [PATCH 01/16] blk-mq: kill q->mq_map Jens Axboe
2018-10-31  0:28   ` Sagi Grimberg
2018-10-30 18:32 ` [PATCH 02/16] blk-mq: abstract out queue map Jens Axboe
2018-10-31  0:31   ` Sagi Grimberg
2018-10-31 14:17     ` Jens Axboe
2018-10-30 18:32 ` [PATCH 03/16] blk-mq: provide dummy blk_mq_map_queue_type() helper Jens Axboe
2018-10-31  0:32   ` Sagi Grimberg
2018-10-30 18:32 ` [PATCH 04/16] blk-mq: pass in request/bio flags to queue mapping Jens Axboe
2018-10-31  0:37   ` Sagi Grimberg
2018-10-31 14:18     ` Jens Axboe
2018-10-30 18:32 ` [PATCH 05/16] blk-mq: allow software queue to map to multiple hardware queues Jens Axboe
2018-10-31  0:49   ` Sagi Grimberg
2018-10-31 14:19     ` Jens Axboe
2018-10-30 18:32 ` [PATCH 06/16] blk-mq: add 'type' attribute to the sysfs hctx directory Jens Axboe
2018-10-31  0:53   ` Sagi Grimberg
2018-10-31 14:21     ` Jens Axboe
2018-11-01 21:59   ` Omar Sandoval
2018-11-01 22:50     ` Jens Axboe
2018-10-30 18:32 ` [PATCH 07/16] blk-mq: support multiple hctx maps Jens Axboe
2018-10-31  0:59   ` Sagi Grimberg
2018-10-31 14:23     ` Jens Axboe
2018-10-30 18:32 ` [PATCH 08/16] blk-mq: separate number of hardware queues from nr_cpu_ids Jens Axboe
2018-10-31  1:00   ` Sagi Grimberg
2018-10-30 18:32 ` [PATCH 09/16] blk-mq: cache request hardware queue mapping Jens Axboe
2018-10-31  1:01   ` Sagi Grimberg
2018-11-01  9:27   ` Hannes Reinecke
2018-11-01 12:22     ` Jens Axboe
2018-10-30 18:32 ` [PATCH 10/16] blk-mq: cleanup and improve list insertion Jens Axboe
2018-10-31  1:03   ` Sagi Grimberg
2018-11-01  9:28   ` Hannes Reinecke
2018-10-30 18:32 ` Jens Axboe [this message]
2018-10-31  1:04   ` [PATCH 11/16] blk-mq: improve plug list sorting Sagi Grimberg
2018-11-01  9:30   ` Hannes Reinecke
2018-10-30 18:32 ` [PATCH 12/16] blk-mq: initial support for multiple queue maps Jens Axboe
2018-10-31  1:14   ` Sagi Grimberg
2018-10-30 18:32 ` [PATCH 13/16] irq: add support for allocating (and affinitizing) sets of IRQs Jens Axboe
2018-10-31  1:17   ` Sagi Grimberg
2018-11-02 14:37   ` Ming Lei
2018-11-02 15:09     ` Keith Busch
2018-11-03  2:22       ` Ming Lei
2018-10-30 18:32 ` [PATCH 14/16] nvme: utilize two queue maps, one for reads and one for writes Jens Axboe
2018-10-31  1:57   ` Sagi Grimberg
2018-10-31 14:32     ` Jens Axboe
2018-10-30 18:32 ` [PATCH 15/16] block: add REQ_HIPRI and inherit it from IOCB_HIPRI Jens Axboe
2018-10-31  1:58   ` Sagi Grimberg
2018-10-30 18:32 ` [PATCH 16/16] nvme: add separate poll queue map Jens Axboe
2018-10-30 18:35 ` [PATCHSET v3 0/16] blk-mq: Add support for multiple queue maps Keith Busch

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