From: Paolo Bonzini <pbonzini@redhat.com>
To: Bart Van Assche <bvanassche@acm.org>,
linux-kernel@vger.kernel.org, kvm@vger.kernel.org
Cc: jejb@linux.ibm.com, martin.petersen@oracle.com,
linux-scsi@vger.kernel.org, stefanha@redhat.com
Subject: Re: [PATCH 2/2] virtio_scsi: implement request batching
Date: Fri, 31 May 2019 11:03:16 +0200 [thread overview]
Message-ID: <ff7aaa01-022b-f55a-4bb2-c293cfd86bdd@redhat.com> (raw)
In-Reply-To: <79490df1-0145-5b40-027a-7e8fb96854d4@acm.org>
On 30/05/19 19:28, Bart Van Assche wrote:
> On 5/30/19 4:28 AM, Paolo Bonzini wrote:
>> @@ -531,7 +547,8 @@ static int virtscsi_queuecommand(struct Scsi_Host
>> *shost,
>> req_size = sizeof(cmd->req.cmd);
>> }
>> - ret = virtscsi_kick_cmd(req_vq, cmd, req_size,
>> sizeof(cmd->resp.cmd));
>> + kick = (sc->flags & SCMD_LAST) != 0;
>> + ret = virtscsi_add_cmd(req_vq, cmd, req_size,
>> sizeof(cmd->resp.cmd), kick);
>
> Have you considered to have the SCSI core call commit_rqs() if bd->last
> is true? I think that would avoid that we need to introduce the
> SCMD_LAST flag and that would also avoid that every SCSI LLD that
> supports a commit_rqs callback has to introduce code to test the
> SCMD_LAST flag.
That is slightly worse for performance, as it unlocks and re-locks the
spinlock.
Paolo
next prev parent reply other threads:[~2019-05-31 9:03 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-05-30 11:28 [PATCH 0/2] scsi: add support for request batching Paolo Bonzini
2019-05-30 11:28 ` [PATCH 1/2] scsi_host: " Paolo Bonzini
2019-05-30 15:36 ` Bart Van Assche
2019-05-30 15:54 ` Paolo Bonzini
2019-05-30 17:54 ` Bart Van Assche
2019-05-31 9:12 ` Paolo Bonzini
2019-05-31 3:27 ` Ming Lei
2019-06-03 8:16 ` Paolo Bonzini
2019-07-05 1:00 ` Ming Lei
2019-06-04 22:40 ` Bart Van Assche
2019-06-19 8:11 ` Hannes Reinecke
2019-06-19 10:31 ` Paolo Bonzini
2019-07-04 13:19 ` Paolo Bonzini
2019-07-05 7:12 ` Hannes Reinecke
2019-07-05 7:44 ` Stefan Hajnoczi
2019-07-05 7:51 ` Hannes Reinecke
2019-05-30 11:28 ` [PATCH 2/2] virtio_scsi: implement " Paolo Bonzini
2019-05-30 17:28 ` Bart Van Assche
2019-05-31 9:03 ` Paolo Bonzini [this message]
2019-07-05 7:52 ` Hannes Reinecke
2019-07-08 9:47 ` Ming Lei
2019-06-10 12:36 ` [PATCH 0/2] scsi: add support for " Stefan Hajnoczi
2019-06-26 13:51 ` Paolo Bonzini
2019-06-26 14:14 ` Douglas Gilbert
2019-06-26 14:50 ` Paolo Bonzini
2019-06-27 3:37 ` Martin K. Petersen
2019-06-27 8:17 ` Paolo Bonzini
2019-07-05 7:13 ` Hannes Reinecke
2019-07-05 11:58 ` Paolo Bonzini
2019-07-12 1:37 ` Martin K. Petersen
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