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From: "Ross S. W. Walker" <RWalker@medallion.com>
To: "Vladislav Bolkhovitin" <vst@vlnb.net>,
	"James Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: <linux-scsi@vger.kernel.org>,
	"iSCSI Enterprise Target Developer List" 
	<iscsitarget-devel@lists.sourceforge.net>,
	<linux-kernel@vger.kernel.org>,
	"Ross Walker" <rswwalker@gmail.com>,
	"scst-devel" <scst-devel@lists.sourceforge.net>,
	<stgt@vger.kernel.org>
Subject: RE: [Scst-devel] [Iscsitarget-devel] ISCSI-SCST	performance (with also IET and STGT data)
Date: Thu, 2 Apr 2009 10:14:45 -0400	[thread overview]
Message-ID: <E2BB8074E5500C42984D980D4BD78EF9029E3D15@MFG-NYC-EXCH2.mfg.prv> (raw)
In-Reply-To: <E2BB8074E5500C42984D980D4BD78EF9029E3D14@MFG-NYC-EXCH2.mfg.prv>

Ross S. W. Walker wrote:
> Vladislav Bolkhovitin wrote:
> > Vladislav Bolkhovitin, on 04/02/2009 11:38 AM wrote:
> > > James Bottomley, on 04/02/2009 12:23 AM wrote:
> > >> 
> > >> SCST explicitly fiddles with the io context to get this to happen.  It
> > >> has a hack to block to export alloc_io_context:
> > >>
> > >> http://marc.info/?t=122893564800003
> > > 
> > > Correct, although I wouldn't call it "fiddle", rather "grouping" ;)
> 
> Call it what you like,
> 
> Vladislav Bolkhovitin wrote:
> > Ross S. W. Walker, on 03/30/2009 10:33 PM wrote:
> > 
> > I would be interested in knowing how your code defeats CFQ's extremely
> > high latency? Does your code reach into the io scheduler too? If not,
> > some code hints would be great.
> 

The above quoting was wrong, for accuracy, it should have read:

Vladislav Bolkhovitin wrote:
> Ross S. W. Walker, on 03/30/2009 10:33 PM wrote:
> > 
> > I would be interested in knowing how your code defeats CFQ's extremely
> > high latency? Does your code reach into the io scheduler too? If not,
> > some code hints would be great.
> 
> Hmm, CFQ doesn't have any extra processing latency, especially 
> "extremely", hence there is nothing to defeat. If it had, how could it 
> been chosen as the default?

Just so there is no misunderstanding who said what here.

-Ross

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WARNING: multiple messages have this Message-ID (diff)
From: "Ross S. W. Walker" <RWalker@medallion.com>
To: Vladislav Bolkhovitin <vst@vlnb.net>,
	James Bottomley <James.Bottomley@HansenPartnership.com>
Cc: linux-scsi@vger.kernel.org,
	iSCSI Enterprise Target Developer List
	<iscsitarget-devel@lists.sourceforge.net>,
	linux-kernel@vger.kernel.org, Ross Walker <rswwalker@gmail.com>,
	scst-devel <scst-devel@lists.sourceforge.net>,
	stgt@vger.kernel.org
Subject: RE: [Scst-devel] [Iscsitarget-devel] ISCSI-SCST	performance (with also IET and STGT data)
Date: Thu, 2 Apr 2009 10:14:45 -0400	[thread overview]
Message-ID: <E2BB8074E5500C42984D980D4BD78EF9029E3D15@MFG-NYC-EXCH2.mfg.prv> (raw)
In-Reply-To: <E2BB8074E5500C42984D980D4BD78EF9029E3D14@MFG-NYC-EXCH2.mfg.prv>

Ross S. W. Walker wrote:
> Vladislav Bolkhovitin wrote:
> > Vladislav Bolkhovitin, on 04/02/2009 11:38 AM wrote:
> > > James Bottomley, on 04/02/2009 12:23 AM wrote:
> > >> 
> > >> SCST explicitly fiddles with the io context to get this to happen.  It
> > >> has a hack to block to export alloc_io_context:
> > >>
> > >> http://marc.info/?t=122893564800003
> > > 
> > > Correct, although I wouldn't call it "fiddle", rather "grouping" ;)
> 
> Call it what you like,
> 
> Vladislav Bolkhovitin wrote:
> > Ross S. W. Walker, on 03/30/2009 10:33 PM wrote:
> > 
> > I would be interested in knowing how your code defeats CFQ's extremely
> > high latency? Does your code reach into the io scheduler too? If not,
> > some code hints would be great.
> 

The above quoting was wrong, for accuracy, it should have read:

Vladislav Bolkhovitin wrote:
> Ross S. W. Walker, on 03/30/2009 10:33 PM wrote:
> > 
> > I would be interested in knowing how your code defeats CFQ's extremely
> > high latency? Does your code reach into the io scheduler too? If not,
> > some code hints would be great.
> 
> Hmm, CFQ doesn't have any extra processing latency, especially 
> "extremely", hence there is nothing to defeat. If it had, how could it 
> been chosen as the default?

Just so there is no misunderstanding who said what here.

-Ross

______________________________________________________________________
This e-mail, and any attachments thereto, is intended only for use by
the addressee(s) named herein and may contain legally privileged
and/or confidential information. If you are not the intended recipient
of this e-mail, you are hereby notified that any dissemination,
distribution or copying of this e-mail, and any attachments thereto,
is strictly prohibited. If you have received this e-mail in error,
please immediately notify the sender and permanently delete the
original and any copy or printout thereof.


  reply	other threads:[~2009-04-02 14:15 UTC|newest]

Thread overview: 34+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-03-30 17:33 ISCSI-SCST performance (with also IET and STGT data) Vladislav Bolkhovitin
     [not found] ` <e2e108260903301106y2b750c23kfab978567f3de3a0@mail.gmail.com>
2009-03-30 18:33   ` [Scst-devel] " Vladislav Bolkhovitin
2009-03-30 18:53     ` Bart Van Assche
2009-03-30 18:53       ` Bart Van Assche
2009-03-31 17:37       ` Vladislav Bolkhovitin
2009-03-31 18:43         ` [Iscsitarget-devel] [Scst-devel] ISCSI-SCST performance (withalso " Ross S. W. Walker
2009-03-31 18:43           ` Ross S. W. Walker
2009-04-01  6:29           ` [Iscsitarget-devel] " Bart Van Assche
2009-04-01  6:29             ` Bart Van Assche
2009-04-01 12:20             ` Ross Walker
2009-04-01 12:20               ` Ross Walker
2009-04-01 20:23               ` James Bottomley
2009-04-01 20:23                 ` James Bottomley
2009-04-02  7:38                 ` [Scst-devel] [Iscsitarget-devel] ISCSI-SCST performance (with also " Vladislav Bolkhovitin
2009-04-02  7:38                   ` Vladislav Bolkhovitin
2009-04-02  9:02                   ` Vladislav Bolkhovitin
2009-04-02  9:02                     ` Vladislav Bolkhovitin
2009-04-02 14:06                     ` Ross S. W. Walker
2009-04-02 14:06                       ` Ross S. W. Walker
2009-04-02 14:14                       ` Ross S. W. Walker [this message]
2009-04-02 14:14                         ` Ross S. W. Walker
2009-04-02 15:36                       ` Vladislav Bolkhovitin
2009-04-02 15:36                         ` Vladislav Bolkhovitin
2009-04-02 17:19                         ` Ross S. W. Walker
2009-04-02 17:19                           ` Ross S. W. Walker
2009-04-01 20:14 ` Bart Van Assche
2009-04-01 20:14   ` Bart Van Assche
2009-04-02 17:16   ` [Scst-devel] " Vladislav Bolkhovitin
2009-04-03 17:08     ` Bart Van Assche
2009-04-03 17:13       ` [Scst-devel] ISCSI-SCST performance (with also IET and STGTdata) Sufficool, Stanley
2009-04-03 17:13         ` Sufficool, Stanley
2009-04-03 17:52         ` Bart Van Assche
2009-04-04  8:04     ` [Scst-devel] ISCSI-SCST performance (with also IET and STGT data) Bart Van Assche
2009-04-17 18:11       ` Vladislav Bolkhovitin

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