lkml.org 
[lkml]   [2019]   [May]   [31]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [PATCH 2/2] virtio_scsi: implement request batching
From
Date
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

\
 
 \ /
  Last update: 2019-05-31 11:03    [W:0.044 / U:33.464 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site