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Message-Id: <20171017050418.22555-2-ming.lei@redhat.com>
Date: Tue, 17 Oct 2017 13:04:17 +0800
From: Ming Lei <ming.lei@...hat.com>
To: Jens Axboe <axboe@...com>, linux-block@...r.kernel.org,
Christoph Hellwig <hch@...radead.org>
Cc: Bart Van Assche <bart.vanassche@...disk.com>,
linux-kernel@...r.kernel.org, linux-scsi@...r.kernel.org,
Omar Sandoval <osandov@...com>,
John Garry <john.garry@...wei.com>,
Ming Lei <ming.lei@...hat.com>
Subject: [PATCH 1/2] SCSI: run idle hctx after delay in scsi_mq_get_budget()
If there isn't any outstanding request in this queue, both
blk-mq's RESTART and SCSI's builtin RESTART can't work,
so we have to deal with this case by running this queue
after delay.
Fixes: d04b6d97d0a1(scsi: implement .get_budget and .put_budget for blk-mq)
Signed-off-by: Ming Lei <ming.lei@...hat.com>
---
drivers/scsi/scsi_lib.c | 13 ++++++++++---
1 file changed, 10 insertions(+), 3 deletions(-)
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index 6f10afaca25b..08c495364b28 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -1959,6 +1959,14 @@ static void scsi_mq_put_budget(struct blk_mq_hw_ctx *hctx)
put_device(&sdev->sdev_gendev);
}
+static void scsi_mq_run_idle_hctx(struct scsi_device *sdev,
+ struct blk_mq_hw_ctx *hctx)
+{
+ if (atomic_read(&sdev->device_busy) == 0 &&
+ !scsi_device_blocked(sdev))
+ blk_mq_delay_run_hw_queue(hctx, SCSI_QUEUE_DELAY);
+}
+
static blk_status_t scsi_mq_get_budget(struct blk_mq_hw_ctx *hctx)
{
struct request_queue *q = hctx->queue;
@@ -1989,6 +1997,7 @@ static blk_status_t scsi_mq_get_budget(struct blk_mq_hw_ctx *hctx)
out_put_device:
put_device(&sdev->sdev_gendev);
out:
+ scsi_mq_run_idle_hctx(sdev, hctx);
return BLK_STS_RESOURCE;
}
@@ -2039,9 +2048,7 @@ static blk_status_t scsi_queue_rq(struct blk_mq_hw_ctx *hctx,
case BLK_STS_OK:
break;
case BLK_STS_RESOURCE:
- if (atomic_read(&sdev->device_busy) == 0 &&
- !scsi_device_blocked(sdev))
- blk_mq_delay_run_hw_queue(hctx, SCSI_QUEUE_DELAY);
+ scsi_mq_run_idle_hctx(sdev, hctx);
break;
default:
/*
--
2.9.5
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