From: Christoph Hellwig <hch@infradead.org>
To: "Nicholas A. Bellinger" <nab@linux-iscsi.org>
Cc: Christoph Hellwig <hch@infradead.org>,
Jens Axboe <axboe@kernel.dk>,
James Bottomley <JBottomley@Parallels.com>,
linux-scsi@vger.kernel.org
Subject: Re: [PATCH 12/15] scsi: initial blk-mq support
Date: Fri, 7 Feb 2014 04:51:47 -0800 [thread overview]
Message-ID: <20140207125147.GA3198@infradead.org> (raw)
In-Reply-To: <1391724663.14985.11.camel@haakon3.risingtidesystems.com>
> Is there extra scsi_mq_done() part that does IPI here even necessary
> anymore..?
>
> I was under the assumption that blk_mq_end_io() is already taking care
> of this..?
blk_mq_end_io does it, but given that the SCSI-specific I/O completion
path is non-trivial I'd rather run it on the indicated CPU as well,
similar to how the old blk-softirq code works. I'll send out a patch
series that should make this area a lot cleaner and avoid having to
implement the IPIs in each driver that wants or needs it soon.
> OK, so your in-lining the allocation of data + protection SGLs from
> blk-mq..
>
> The original prototype code was doing these allocations separately below
> for each pre-allocated cmd, and offering LLD's to optionally
> pre-allocate their own descripts using sh->hostt->cmd_size if
> necessary..
>
> This was necessary to eliminate all fast-path allocations for
> virtio-scsi, and I'd like to see something similar here as an optional
> feature as well.
It's present. The cmd_size host_template parameter is added in the
previous series, and we still take it into account.
next prev parent reply other threads:[~2014-02-07 12:51 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-02-05 12:41 [PATCH 00/15] A different approach for using blk-mq in the SCSI layer Christoph Hellwig
2014-02-05 12:41 ` [PATCH 01/15] block: rework flush sequencing for blk-mq Christoph Hellwig
2014-02-06 2:08 ` Muthu Kumar
2014-02-06 16:18 ` Christoph Hellwig
2014-02-05 12:41 ` [PATCH 02/15] blk-mq: support at_head inserations for blk_execute_rq Christoph Hellwig
2014-02-06 2:27 ` Muthu Kumar
2014-02-06 16:17 ` Christoph Hellwig
2014-02-06 17:05 ` Muthu Kumar
2014-02-06 17:10 ` Christoph Hellwig
2014-02-05 12:41 ` [PATCH 03/15] blk-mq: divert __blk_put_request for MQ ops Christoph Hellwig
2014-02-05 12:41 ` [PATCH 04/15] blk-mq: handle dma_drain_size Christoph Hellwig
2014-02-05 12:41 ` [PATCH 05/15] blk-mq: initialize sg_reserved_size Christoph Hellwig
2014-02-05 12:41 ` [PATCH 06/15] scsi: reintroduce scsi_driver.init_command Christoph Hellwig
2014-02-05 12:41 ` [PATCH 07/15] block: remove unprep_rq_fn Christoph Hellwig
2014-02-05 12:41 ` [PATCH 08/15] scsi: cleanup scsi_end_request calling conventions Christoph Hellwig
2014-02-05 12:41 ` [PATCH 09/15] scsi: centralize command re-queueing in scsi_dispatch_fn Christoph Hellwig
2014-02-05 12:41 ` [PATCH 10/15] scsi: split __scsi_queue_insert Christoph Hellwig
2014-02-05 12:41 ` [PATCH 11/15] scsi: factor out __scsi_init_queue Christoph Hellwig
2014-02-05 12:41 ` [PATCH 12/15] scsi: initial blk-mq support Christoph Hellwig
2014-02-06 8:38 ` Sagi Grimberg
2014-02-06 16:16 ` Christoph Hellwig
2014-02-06 22:11 ` Nicholas A. Bellinger
2014-02-07 8:45 ` Mike Christie
2014-02-07 12:42 ` Christoph Hellwig
2014-02-07 12:51 ` Christoph Hellwig [this message]
2014-02-05 12:41 ` [PATCH 13/15] scsi: partially stub out scsi_adjust_queue_depth when using blk-mq Christoph Hellwig
2014-02-05 12:41 ` [PATCH 14/15] iscsi_tcp: use blk_mq Christoph Hellwig
2014-02-05 12:41 ` [PATCH 15/15] virtio_scsi: " Christoph Hellwig
2014-02-10 11:35 ` [PATCH 00/15] A different approach for using blk-mq in the SCSI layer Christoph Hellwig
2014-02-10 19:38 ` Nicholas A. Bellinger
2014-02-24 14:46 ` Christoph Hellwig
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