From: Jeff Garzik <jgarzik@pobox.com>
To: Lin Ming <ming.m.lin@intel.com>
Cc: linux-ide@vger.kernel.org, linux-kernel@vger.kernel.org,
Tejun Heo <tj@kernel.org>, "Rafael J. Wysocki" <rjw@sisk.pl>,
Priyanka Gupta <ankaguptaca@gmail.com>,
Zhang Rui <rui.zhang@intel.com>,
"Huang, Ying" <ying.huang@intel.com>
Subject: Re: [RFC] ata port runtime pm
Date: Thu, 27 Oct 2011 23:37:54 -0400 [thread overview]
Message-ID: <4EAA2392.40105@pobox.com> (raw)
In-Reply-To: <1319772072.24236.0.camel@minggr>
On 10/27/2011 11:21 PM, Lin Ming wrote:
> @@ -3208,6 +3209,11 @@ int ata_scsi_queuecmd(struct Scsi_Host *shost, struct scsi_cmnd *cmd)
>
> ap = ata_shost_to_port(shost);
>
> + if (pm_runtime_suspended(&ap->tdev))
> + pm_runtime_resume(&ap->tdev);
> + pm_runtime_mark_last_busy(&ap->tdev);
> + pm_request_autosuspend(&ap->tdev);
> +
> spin_lock_irqsave(ap->lock, irq_flags);
>
Putting this into the core command dispatch fast-path is rather
disappointing. That's at least one additional lock, plus some atomic
instructions and tests.
Jeff
next prev parent reply other threads:[~2011-10-28 3:37 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-10-28 3:21 [RFC] ata port runtime pm Lin Ming
2011-10-28 3:37 ` Jeff Garzik [this message]
2011-10-28 5:36 ` Lin Ming
2011-10-28 17:31 ` Rafael J. Wysocki
2011-10-28 18:51 ` Alan Stern
2011-11-01 8:12 ` Lin Ming
2011-11-01 19:34 ` Alan Stern
-- strict thread matches above, loose matches on Subject: below --
2011-10-28 3:20 Lin Ming
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