From: John Garry <john.garry@huawei.com>
To: Ming Lei <ming.lei@redhat.com>, Jens Axboe <axboe@kernel.dk>,
<linux-block@vger.kernel.org>, <linux-scsi@vger.kernel.org>,
"Martin K . Petersen" <martin.petersen@oracle.com>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>,
Bart Van Assche <bvanassche@acm.org>,
Hannes Reinecke <hare@suse.com>,
Don Brace <don.brace@microsemi.com>,
Kashyap Desai <kashyap.desai@broadcom.com>,
"Sathya Prakash" <sathya.prakash@broadcom.com>,
Christoph Hellwig <hch@lst.de>
Subject: Re: [PATCH 1/9] blk-mq: allow hw queues to share hostwide tags
Date: Wed, 5 Jun 2019 15:10:51 +0100 [thread overview]
Message-ID: <0f1773af-170a-a6b5-54ce-274dacb2b63a@huawei.com> (raw)
In-Reply-To: <20190531022801.10003-2-ming.lei@redhat.com>
On 31/05/2019 03:27, Ming Lei wrote:
> index 32b8ad3d341b..49d73d979cb3 100644
> --- a/block/blk-mq.c
> +++ b/block/blk-mq.c
> @@ -2433,6 +2433,11 @@ static bool __blk_mq_alloc_rq_map(struct blk_mq_tag_set *set, int hctx_idx)
> {
> int ret = 0;
>
Hi Ming,
> + if ((set->flags & BLK_MQ_F_HOST_TAGS) && hctx_idx) {
> + set->tags[hctx_idx] = set->tags[0];
Here we set all tags same as that of hctx index 0.
> + return true;
As such, I think that the error handling in __blk_mq_alloc_rq_maps() is
made a little fragile:
__blk_mq_alloc_rq_maps(struct blk_mq_tag_set *set)
{
int i;
for (i = 0; i < set->nr_hw_queues; i++)
if (!__blk_mq_alloc_rq_map(set, i))
goto out_unwind;
return 0;
out_unwind:
while (--i >= 0)
blk_mq_free_rq_map(set->tags[i]);
return -ENOMEM;
}
If __blk_mq_alloc_rq_map(, i > 1) fails for when BLK_MQ_F_HOST_TAGS FLAG
is set (even though today it can't), then we would try to free
set->tags[0] multiple times.
> + }
> +
> set->tags[hctx_idx] = blk_mq_alloc_rq_map(set, hctx_idx,
> set->queue_depth, set->reserved_tags);
Thanks,
John
> if (!set->tags[hctx_idx])
> @@ -2451,6 +2456,9 @@ static bool __blk_mq_alloc_rq_map(struct blk_mq_tag_set *set, int hctx_idx)
> static void blk_mq_free_map_and_requests(struct blk_mq_tag_set *set,
>
next prev parent reply other threads:[~2019-06-05 14:11 UTC|newest]
Thread overview: 48+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-05-31 2:27 [PATCH 0/9] blk-mq/scsi: convert private reply queue into blk_mq hw queue Ming Lei
2019-05-31 2:27 ` [PATCH 1/9] blk-mq: allow hw queues to share hostwide tags Ming Lei
2019-05-31 6:07 ` Hannes Reinecke
2019-05-31 15:37 ` Bart Van Assche
2019-06-24 8:44 ` Ming Lei
2019-06-05 14:10 ` John Garry [this message]
2019-06-24 8:46 ` Ming Lei
2019-06-24 13:14 ` John Garry
2019-05-31 2:27 ` [PATCH 2/9] block: null_blk: introduce module parameter of 'g_host_tags' Ming Lei
2019-05-31 6:08 ` Hannes Reinecke
2019-05-31 15:39 ` Bart Van Assche
2019-06-24 8:43 ` Ming Lei
2019-06-02 1:56 ` Minwoo Im
2019-05-31 2:27 ` [PATCH 3/9] scsi: Add template flag 'host_tagset' Ming Lei
2019-05-31 6:08 ` Hannes Reinecke
2019-05-31 2:27 ` [PATCH 4/9] scsi_debug: support host tagset Ming Lei
2019-05-31 6:09 ` Hannes Reinecke
2019-06-02 2:03 ` Minwoo Im
2019-06-02 17:01 ` Douglas Gilbert
2019-05-31 2:27 ` [PATCH 5/9] scsi: introduce scsi_cmnd_hctx_index() Ming Lei
2019-05-31 6:10 ` Hannes Reinecke
2019-05-31 2:27 ` [PATCH 6/9] scsi: hpsa: convert private reply queue to blk-mq hw queue Ming Lei
2019-05-31 6:15 ` Hannes Reinecke
2019-05-31 6:30 ` Ming Lei
2019-05-31 6:40 ` Hannes Reinecke
2019-05-31 2:27 ` [PATCH 7/9] scsi: hisi_sas_v3: " Ming Lei
2019-05-31 6:20 ` Hannes Reinecke
2019-05-31 6:34 ` Ming Lei
2019-05-31 6:42 ` Hannes Reinecke
2019-05-31 7:14 ` Ming Lei
2019-05-31 11:38 ` John Garry
2019-06-03 11:00 ` Ming Lei
2019-06-03 13:00 ` John Garry
2019-06-04 13:37 ` Ming Lei
2019-05-31 2:28 ` [PATCH 8/9] scsi: megaraid: " Ming Lei
2019-05-31 6:22 ` Hannes Reinecke
2019-06-01 21:41 ` Kashyap Desai
2019-06-02 6:42 ` Ming Lei
2019-06-02 7:48 ` Ming Lei
2019-06-02 16:34 ` Kashyap Desai
2019-06-03 3:56 ` Ming Lei
2019-06-03 10:00 ` Kashyap Desai
2019-06-07 9:45 ` Kashyap Desai
2019-05-31 2:28 ` [PATCH 9/9] scsi: mp3sas: " Ming Lei
2019-05-31 6:23 ` Hannes Reinecke
2019-06-06 11:58 ` Sreekanth Reddy
2019-06-04 8:49 ` [PATCH 0/9] blk-mq/scsi: convert private reply queue into blk_mq " John Garry
2019-08-13 8:30 ` John Garry
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