From: Ming Lei <ming.lei@redhat.com>
To: John Garry <john.garry@huawei.com>
Cc: axboe@kernel.dk, jejb@linux.ibm.com, martin.petersen@oracle.com,
hare@suse.de, bvanassche@acm.org, hch@infradead.org,
linux-block@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-scsi@vger.kernel.org,
virtualization@lists.linux-foundation.org,
esc.storagedev@microsemi.com, chenxiang66@hisilicon.com,
Hannes Reinecke <hare@suse.com>
Subject: Re: [PATCH RFC v2 01/24] scsi: add 'nr_reserved_cmds' field to the SCSI host template
Date: Wed, 11 Mar 2020 07:08:35 +0800 [thread overview]
Message-ID: <20200310230835.GA16056@ming.t460p> (raw)
In-Reply-To: <1583857550-12049-2-git-send-email-john.garry@huawei.com>
On Wed, Mar 11, 2020 at 12:25:27AM +0800, John Garry wrote:
> From: Hannes Reinecke <hare@suse.com>
>
> Add a new field 'nr_reserved_cmds' to the SCSI host template to
> instruct the block layer to set aside a tag space for reserved
> commands.
>
> Signed-off-by: Hannes Reinecke <hare@suse.com>
> ---
> drivers/scsi/scsi_lib.c | 1 +
> include/scsi/scsi_host.h | 6 ++++++
> 2 files changed, 7 insertions(+)
>
> diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
> index 610ee41fa54c..2967325df7a0 100644
> --- a/drivers/scsi/scsi_lib.c
> +++ b/drivers/scsi/scsi_lib.c
> @@ -1896,6 +1896,7 @@ int scsi_mq_setup_tags(struct Scsi_Host *shost)
> shost->tag_set.ops = &scsi_mq_ops_no_commit;
> shost->tag_set.nr_hw_queues = shost->nr_hw_queues ? : 1;
> shost->tag_set.queue_depth = shost->can_queue;
> + shost->tag_set.reserved_tags = shost->nr_reserved_cmds;
You reserve tags for special usage, meantime the whole queue depth
isn't increased, that means the tags for IO request is decreased given
reserved tags can't be used for IO, so IO performance may be effected.
If not the case, please explain a bit in commit log.
Thanks,
Ming
next prev parent reply other threads:[~2020-03-10 23:08 UTC|newest]
Thread overview: 49+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-03-10 16:25 [PATCH RFC v2 00/24] scsi: enable reserved commands for LLDDs John Garry
2020-03-10 16:25 ` [PATCH RFC v2 01/24] scsi: add 'nr_reserved_cmds' field to the SCSI host template John Garry
2020-03-10 23:08 ` Ming Lei [this message]
2020-03-11 6:55 ` Hannes Reinecke
2020-03-11 8:00 ` Ming Lei
2020-03-10 16:25 ` [PATCH RFC v2 02/24] scsi: allocate separate queue for reserved commands John Garry
2020-03-10 18:32 ` Christoph Hellwig
2020-03-10 21:08 ` John Garry
2020-03-11 6:22 ` Christoph Hellwig
2020-03-11 6:58 ` Hannes Reinecke
2020-03-11 7:51 ` John Garry
2020-04-06 9:05 ` Hannes Reinecke
2020-04-07 11:54 ` John Garry
2020-04-07 14:00 ` Hannes Reinecke
2020-04-07 14:35 ` John Garry
2020-04-07 14:45 ` Hannes Reinecke
2020-04-07 15:19 ` John Garry
2020-04-07 16:30 ` Christoph Hellwig
2020-04-23 14:13 ` John Garry
2020-04-23 14:49 ` Hannes Reinecke
2020-04-23 15:33 ` John Garry
2020-03-10 16:25 ` [PATCH RFC v2 03/24] blk-mq: Implement blk_mq_rq_is_reserved() John Garry
2020-03-10 16:25 ` [PATCH RFC v2 04/24] scsi: Add scsi_{get, put}_reserved_cmd() John Garry
2020-03-10 16:25 ` [PATCH RFC v2 05/24] csiostor: use reserved command for LUN reset John Garry
2020-03-10 16:25 ` [PATCH RFC v2 06/24] scsi: add scsi_cmd_from_priv() John Garry
2020-03-10 16:25 ` [PATCH RFC v2 07/24] virtio_scsi: use reserved commands for TMF John Garry
2020-03-10 16:25 ` [PATCH RFC v2 08/24] scsi: add host tagset busy iterator John Garry
2020-03-10 16:25 ` [PATCH RFC v2 09/24] fnic: use reserved commands John Garry
2020-03-10 16:25 ` [PATCH RFC v2 10/24] fnic: use scsi_host_tagset_busy_iter() to traverse commands John Garry
2020-03-10 16:25 ` [PATCH RFC v2 11/24] hpsa: move hpsa_hba_inquiry after scsi_add_host() John Garry
2020-03-10 16:25 ` [PATCH RFC v2 12/24] hpsa: use reserved commands John Garry
2020-03-11 8:10 ` Ming Lei
2020-03-17 9:38 ` John Garry
2020-03-17 9:48 ` Hannes Reinecke
2020-03-30 13:42 ` John Garry
2020-03-10 16:25 ` [PATCH RFC v2 13/24] hpsa: use blk_mq_tagset_busy_iter() to traverse outstanding commands John Garry
2020-03-10 16:25 ` [PATCH RFC v2 14/24] hpsa: drop refcount field from CommandList John Garry
2020-03-10 16:25 ` [PATCH RFC v2 15/24] snic: use reserved commands John Garry
2020-03-10 16:25 ` [PATCH RFC v2 16/24] snic: use tagset iter for traversing commands John Garry
2020-03-10 16:25 ` [PATCH RFC v2 17/24] aacraid: move scsi_add_host() John Garry
2020-03-10 16:25 ` [PATCH RFC v2 18/24] aacraid: use private commands John Garry
2020-03-10 16:25 ` [PATCH RFC v2 19/24] aacraid: replace cmd_list with scsi_host_tagset_busy_iter() John Garry
2020-03-10 16:25 ` [PATCH RFC v2 20/24] aacraid: use scsi_host_tagset_busy_iter() to traverse outstanding commands John Garry
2020-03-10 16:25 ` [PATCH RFC v2 21/24] dpt_i2o: drop cmd_list usage John Garry
2020-03-10 16:25 ` [PATCH RFC v2 22/24] scsi: drop scsi command list John Garry
2020-03-10 18:35 ` Christoph Hellwig
2020-03-10 20:47 ` John Garry
2020-03-10 16:25 ` [PATCH RFC v2 23/24] scsi: libsas: aic94xx: hisi_sas: mvsas: pm8001: Allocate Scsi_cmd for slow task John Garry
2020-03-10 16:25 ` [PATCH RFC v2 24/24] scsi: hisi_sas: Use libsas slow task SCSI command John Garry
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