From: Douglas Gilbert <dgilbert@interlog.com>
To: Phillip Susi <psusi@ubuntu.com>,
James Bottomley <James.Bottomley@HansenPartnership.com>
Cc: todd.e.brandt@linux.intel.com, linux-ide@vger.kernel.org,
linux-scsi@vger.kernel.org, tj@kernel.org
Subject: Re: [PATCH 1/3] sd: don't bother spinning up disks on resume
Date: Sun, 17 Nov 2013 18:54:34 -0500 [thread overview]
Message-ID: <5289573A.9070307@interlog.com> (raw)
In-Reply-To: <5288EBA6.3070609@ubuntu.com>
On 13-11-17 11:15 AM, Phillip Susi wrote:
> -----BEGIN PGP SIGNED MESSAGE-----
> Hash: SHA512
>
> On 11/17/2013 01:43 AM, James Bottomley wrote:
>> OK, so three people have now told you that's not how the code
>> works. Why don't you just read it? because there's not really much
>> point us reading your patches until you do.
>
> I have, which is why I said it handles it via scsi_eh_stu. If I'm not
> understanding it correctly, then by all means, explain.
Even if the SCSI EH code does spin-up the disk,
it is inefficient and undesirable to send a device
into EH for what is a normal, predictable situation
(i.e. that a SCSI disk will need a START STOP UNIT
(start) command as part of a resume operation).
A big server machine could have thousands of SCSI
disks (many potentially virtual). Sending them all
into EH during a resume would be a really good
test for EH, but horrible for performance. If I was
designing the SCSI EH I would probably assume not
all disks would go into EH at roughly the same time.
Also if that many devices went into EH on the same
controller (HBA) it might be reasonable to assume
that the controller they share needs resetting.
Doug Gilbert
next prev parent reply other threads:[~2013-11-17 23:54 UTC|newest]
Thread overview: 165+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-10-17 19:33 [PATCH/RESEND v2 0/2] SATA disk resume time optimization Todd E Brandt
2013-11-07 1:53 ` Phillip Susi
2013-11-07 1:57 ` [PATCH 1/3] sd: don't bother spinning up disks on resume Phillip Susi
2013-11-07 18:21 ` Douglas Gilbert
2013-11-07 21:16 ` Phillip Susi
2013-11-16 18:20 ` James Bottomley
2013-11-17 3:50 ` Phillip Susi
2013-11-17 6:43 ` James Bottomley
2013-11-17 16:15 ` Phillip Susi
2013-11-17 23:54 ` Douglas Gilbert [this message]
2013-11-18 1:06 ` Phillip Susi
2013-11-18 15:54 ` Phillip Susi
2013-11-20 14:23 ` Mark Lord
2013-11-20 14:48 ` Phillip Susi
2013-11-28 1:39 ` Phillip Susi
2013-11-18 0:09 ` James Bottomley
2013-11-18 1:11 ` Phillip Susi
2013-11-16 5:23 ` Mark Lord
2013-11-16 14:52 ` Phillip Susi
2013-11-07 1:57 ` [PATCH 2/3] libata: resume in the background Phillip Susi
2013-11-07 1:57 ` [PATCH 3/3] libata: don't start disks on resume Phillip Susi
2013-11-09 1:20 ` [PATCH/RESEND v2 0/2] SATA disk resume time optimization Todd E Brandt
2013-11-09 20:59 ` Phillip Susi
2013-11-09 21:03 ` [PATCH 0/6] Let sleeping disks lie Phillip Susi
2013-12-16 23:30 ` Phillip Susi
2013-12-16 23:30 ` [PATCH 1/6] libata: use sleep instead of standby command Phillip Susi
2013-12-16 23:30 ` [PATCH 2/6] libata: avoid waking disk for several commands Phillip Susi
2013-12-16 23:30 ` [PATCH 3/6] libata: resume in the background Phillip Susi
2014-01-10 22:26 ` Dan Williams
2014-01-11 2:25 ` Phillip Susi
2014-01-11 3:11 ` Dan Williams
2013-12-16 23:30 ` [PATCH 4/6] libata: don't start disks on resume Phillip Susi
2013-12-16 23:30 ` [PATCH 5/6] sd: don't start disks on system resume Phillip Susi
2013-12-17 6:43 ` James Bottomley
2013-12-17 15:01 ` Phillip Susi
2013-12-17 17:48 ` James Bottomley
2013-12-17 18:30 ` Phillip Susi
2013-12-16 23:30 ` [PATCH 6/6] libata: return power status in REQUEST SENSE command Phillip Susi
2013-12-17 18:02 ` Sergei Shtylyov
2013-12-17 18:35 ` Phillip Susi
2014-01-06 2:14 ` REQ_PM vs REQ_TYPE_PM_RESUME Phillip Susi
2014-01-06 7:36 ` Sujit Reddy Thumma
2014-01-06 9:15 ` Aaron Lu
2014-01-06 14:40 ` Phillip Susi
2014-01-06 15:38 ` Alan Stern
2014-01-07 2:44 ` Phillip Susi
2014-01-07 15:20 ` Alan Stern
2014-01-07 15:40 ` Phillip Susi
2014-01-07 15:56 ` Alan Stern
2014-01-09 18:29 ` Douglas Gilbert
2014-01-09 19:20 ` Phillip Susi
2014-01-10 5:23 ` Douglas Gilbert
2014-01-10 14:29 ` Phillip Susi
2014-01-07 7:49 ` Aaron Lu
2014-01-07 14:50 ` Phillip Susi
2014-01-08 1:03 ` Aaron Lu
2014-01-08 1:16 ` Phillip Susi
2014-01-08 1:32 ` Aaron Lu
2014-01-08 1:53 ` Phillip Susi
2014-01-08 2:11 ` Aaron Lu
2014-01-08 2:19 ` Phillip Susi
2014-01-08 2:36 ` Aaron Lu
2014-01-08 5:24 ` Phillip Susi
2014-01-08 7:00 ` Aaron Lu
2014-01-08 19:30 ` Phillip Susi
2014-01-07 15:25 ` Alan Stern
2014-01-07 15:43 ` Phillip Susi
2014-01-07 16:08 ` Alan Stern
2014-01-07 16:37 ` Phillip Susi
2014-01-07 18:05 ` Alan Stern
2014-01-07 18:43 ` Phillip Susi
2014-01-07 19:18 ` Alan Stern
2014-01-07 23:47 ` Phillip Susi
2014-01-08 17:46 ` Alan Stern
2014-01-08 18:31 ` Alan Stern
2014-01-08 20:44 ` Allow runtime suspend during system resume Alan Stern
2014-01-08 21:17 ` Phillip Susi
2014-01-08 21:34 ` Alan Stern
2014-01-09 10:14 ` Ulf Hansson
2014-01-09 15:41 ` Alan Stern
2014-01-08 22:55 ` Rafael J. Wysocki
2014-01-08 23:24 ` Alan Stern
2014-01-09 0:05 ` Rafael J. Wysocki
2014-01-09 15:32 ` Alan Stern
2014-01-09 15:50 ` Phillip Susi
2014-01-09 16:08 ` Alan Stern
2014-01-09 16:30 ` Phillip Susi
2014-01-09 17:04 ` Alan Stern
2014-01-10 1:25 ` Rafael J. Wysocki
2014-01-10 1:55 ` Phillip Susi
2014-01-10 13:35 ` Rafael J. Wysocki
2014-01-10 14:46 ` Phillip Susi
2014-01-10 15:25 ` Alan Stern
2014-01-10 23:02 ` Rafael J. Wysocki
2014-01-11 2:08 ` Phillip Susi
2014-01-11 22:50 ` Alan Stern
2014-01-12 1:50 ` Phillip Susi
2014-01-11 22:34 ` Alan Stern
2014-01-08 20:20 ` REQ_PM vs REQ_TYPE_PM_RESUME Phillip Susi
2014-01-08 21:21 ` Alan Stern
2014-01-08 21:50 ` Phillip Susi
2014-01-09 1:29 ` Aaron Lu
2014-01-09 12:17 ` Rafael J. Wysocki
2014-01-09 13:18 ` Rafael J. Wysocki
2014-01-09 15:40 ` Alan Stern
2014-01-09 15:53 ` Phillip Susi
2014-01-09 16:14 ` Alan Stern
2014-01-09 16:34 ` Phillip Susi
2014-01-09 17:06 ` Alan Stern
2014-01-16 16:59 ` Disk spin-up optimization during system resume Alan Stern
2014-01-16 18:04 ` Todd E Brandt
2014-01-16 18:33 ` Phillip Susi
2014-01-16 20:05 ` Alan Stern
2014-01-16 22:04 ` Todd E Brandt
2014-01-17 14:57 ` Alan Stern
2014-01-17 19:31 ` Dan Williams
2014-01-17 20:15 ` Alan Stern
2014-01-17 20:24 ` Tejun Heo
2014-01-17 20:55 ` Phillip Susi
2014-01-18 14:04 ` Tejun Heo
2014-01-18 1:36 ` Todd E Brandt
2014-01-18 1:41 ` Alan Stern
2014-01-18 2:15 ` Dan Williams
2014-01-18 2:33 ` Alan Stern
2014-01-18 3:24 ` Phillip Susi
2014-01-18 13:59 ` Tejun Heo
2014-01-17 20:49 ` Phillip Susi
2014-01-17 22:17 ` Dan Williams
2014-01-18 3:18 ` Phillip Susi
2014-01-18 4:09 ` Dan Williams
2014-01-18 14:08 ` Alan Stern
2014-01-21 10:12 ` Dan Williams
2014-01-21 14:37 ` Phillip Susi
2014-01-21 16:03 ` Alan Stern
2014-01-21 16:18 ` Phillip Susi
2014-01-21 16:49 ` Alan Stern
2014-01-21 15:44 ` Alan Stern
2014-01-21 16:18 ` Dan Williams
2014-01-21 16:55 ` Dan Williams
2014-01-20 12:38 ` CrashPlan Pro
2014-01-20 14:30 ` Phillip Susi
2014-01-18 1:24 ` Todd E Brandt
2014-01-18 3:20 ` Phillip Susi
2014-01-16 18:39 ` Phillip Susi
2014-01-16 20:08 ` Alan Stern
2014-01-17 10:16 ` Oliver Neukum
2014-01-17 10:21 ` Tejun Heo
2014-01-17 18:18 ` Alan Stern
2014-01-17 18:39 ` James Bottomley
2014-01-17 19:07 ` Tejun Heo
2013-11-09 21:03 ` [PATCH 1/6] libata: use sleep instead of standby command Phillip Susi
2013-11-09 21:03 ` [PATCH 2/6] libata: avoid waking disk to check power Phillip Susi
2013-11-11 13:05 ` Sergei Shtylyov
2013-11-09 21:03 ` [PATCH 3/6] sd: don't bother spinning up disks on resume Phillip Susi
2013-11-11 13:08 ` Sergei Shtylyov
2013-11-11 14:28 ` Phillip Susi
2013-11-09 21:03 ` [PATCH 4/6] libata: resume in the background Phillip Susi
2013-11-11 13:10 ` Sergei Shtylyov
2013-11-09 21:03 ` [PATCH 5/6] libata: don't start disks on resume Phillip Susi
2013-11-09 21:03 ` [PATCH 6/6] libata: fake some more commands when drive is sleeping Phillip Susi
2013-11-11 16:59 ` [PATCH/RESEND v2 0/2] SATA disk resume time optimization Todd E Brandt
2013-11-11 17:08 ` Phillip Susi
2013-12-17 12:15 ` Tejun Heo
2013-12-17 14:24 ` Phillip Susi
2013-11-27 16:18 ` Phillip Susi
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