From: Mark Salter <msalter@redhat.com>
To: Will Deacon <will.deacon@arm.com>
Cc: Chen Peter-B29397 <B29397@freescale.com>,
Greg KH <greg@kroah.com>,
"ming.lei@canonical.com" <ming.lei@canonical.com>,
Russell King <linux@arm.linux.org.uk>,
"linux-usb@vger.kernel.org" <linux-usb@vger.kernel.org>,
"stern@rowland.harvard.edu" <stern@rowland.harvard.edu>,
"linux-omap@vger.kernel.org" <linux-omap@vger.kernel.org>,
"linux-arm-kernel@lists.infradead.org"
<linux-arm-kernel@lists.infradead.org>
Subject: Re: [PATCH] usb: ehci: make HC see up-to-date qh/qtd descriptor ASAP
Date: Wed, 31 Aug 2011 09:43:33 -0400 [thread overview]
Message-ID: <1314798215.2344.76.camel@deneb.redhat.com> (raw)
In-Reply-To: <20110831084922.GA8777@e102144-lin.cambridge.arm.com>
On Wed, 2011-08-31 at 09:49 +0100, Will Deacon wrote:
> On Wed, Aug 31, 2011 at 01:23:47AM +0100, Chen Peter-B29397 wrote:
> > One question: why this write buffer issue did not happen at UP ARM V7 platform, whose dma buffer
> > also uncache, but bufferable?
>
> Which CPU was on this platform?
Using a 3.1.0-rc4+ kernel on a Pandaboard, and running 'hdparm -t' on a
usb disk drive, I see ~5.8MB/s read speed. Same kernel, but passing
nosmp on the commandline, I see 20.3MB/s.
Can someone explain why nosmp would make such a difference?
--Mark
WARNING: multiple messages have this Message-ID (diff)
From: msalter@redhat.com (Mark Salter)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH] usb: ehci: make HC see up-to-date qh/qtd descriptor ASAP
Date: Wed, 31 Aug 2011 09:43:33 -0400 [thread overview]
Message-ID: <1314798215.2344.76.camel@deneb.redhat.com> (raw)
In-Reply-To: <20110831084922.GA8777@e102144-lin.cambridge.arm.com>
On Wed, 2011-08-31 at 09:49 +0100, Will Deacon wrote:
> On Wed, Aug 31, 2011 at 01:23:47AM +0100, Chen Peter-B29397 wrote:
> > One question: why this write buffer issue did not happen at UP ARM V7 platform, whose dma buffer
> > also uncache, but bufferable?
>
> Which CPU was on this platform?
Using a 3.1.0-rc4+ kernel on a Pandaboard, and running 'hdparm -t' on a
usb disk drive, I see ~5.8MB/s read speed. Same kernel, but passing
nosmp on the commandline, I see 20.3MB/s.
Can someone explain why nosmp would make such a difference?
--Mark
next prev parent reply other threads:[~2011-08-31 13:44 UTC|newest]
Thread overview: 65+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-08-30 16:03 [PATCH] usb: ehci: make HC see up-to-date qh/qtd descriptor ASAP ming.lei-Z7WLFzj8eWMS+FvcfC7Uqw
2011-08-30 16:03 ` ming.lei at canonical.com
2011-08-30 16:15 ` Alan Stern
2011-08-30 16:15 ` Alan Stern
2011-08-30 16:38 ` Mark Salter
2011-08-30 16:38 ` Mark Salter
2011-08-30 17:15 ` Alan Stern
2011-08-30 17:15 ` Alan Stern
2011-08-30 18:45 ` Mark Salter
2011-08-30 18:45 ` Mark Salter
2011-08-30 17:26 ` Will Deacon
2011-08-30 17:26 ` Will Deacon
[not found] ` <20110830172642.GE3464-SGELLbQ0bobZROr8t4l/smS4ubULX0JqMm0uRHvK7Nw@public.gmane.org>
2011-08-30 17:48 ` Greg KH
2011-08-30 17:48 ` Greg KH
2011-08-30 17:54 ` Will Deacon
2011-08-30 17:54 ` Will Deacon
[not found] ` <20110830175432.GG3464-SGELLbQ0bobZROr8t4l/smS4ubULX0JqMm0uRHvK7Nw@public.gmane.org>
2011-08-31 0:23 ` Chen Peter-B29397
2011-08-31 0:23 ` Chen Peter-B29397
2011-08-31 8:49 ` Will Deacon
2011-08-31 8:49 ` Will Deacon
2011-08-31 12:33 ` Chen Peter-B29397
2011-08-31 12:33 ` Chen Peter-B29397
2011-08-31 13:43 ` Mark Salter [this message]
2011-08-31 13:43 ` Mark Salter
2011-08-31 15:21 ` Will Deacon
2011-08-31 15:21 ` Will Deacon
2011-08-31 15:27 ` Mark Salter
2011-08-31 15:27 ` Mark Salter
2011-08-31 16:12 ` Marc Zyngier
2011-08-31 16:12 ` Marc Zyngier
2011-08-31 16:55 ` Marc Dietrich
2011-08-31 16:55 ` Marc Dietrich
2011-09-01 10:34 ` Marc Zyngier
2011-09-01 10:34 ` Marc Zyngier
[not found] ` <4E5F5FA9.3010305-5wv7dgnIgG8@public.gmane.org>
2011-09-01 11:13 ` Marc Dietich
2011-09-01 11:13 ` Marc Dietich
2011-09-01 19:08 ` Stephen Warren
2011-09-01 19:08 ` Stephen Warren
2011-09-02 9:50 ` Marc Zyngier
2011-09-02 9:50 ` Marc Zyngier
2011-09-02 17:07 ` Stephen Warren
2011-09-02 17:07 ` Stephen Warren
[not found] ` <74CDBE0F657A3D45AFBB94109FB122FF04B327A383-C7FfzLzN0UxDw2glCA4ptUEOCMrvLtNR@public.gmane.org>
2011-09-02 11:13 ` Marc Dietich
2011-09-02 11:13 ` Marc Dietich
2011-08-31 17:46 ` Nicolas Pitre
2011-08-31 17:46 ` Nicolas Pitre
2011-08-31 17:51 ` Will Deacon
2011-08-31 17:51 ` Will Deacon
[not found] ` <20110831175147.GI8777-SGELLbQ0bobZROr8t4l/smS4ubULX0JqMm0uRHvK7Nw@public.gmane.org>
2011-08-31 18:19 ` Rob Herring
2011-08-31 18:19 ` Rob Herring
2011-08-31 18:35 ` Mark Salter
2011-08-31 18:35 ` Mark Salter
2011-08-31 18:49 ` Rob Herring
2011-08-31 18:49 ` Rob Herring
[not found] ` <4E5E8230.9060307-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
2011-08-31 18:58 ` Mark Salter
2011-08-31 18:58 ` Mark Salter
2011-08-31 19:35 ` Will Deacon
2011-08-31 19:35 ` Will Deacon
2011-09-08 22:41 ` Mark Salter
2011-09-08 22:41 ` Mark Salter
[not found] ` <1315521779.2313.29.camel-PDpCo7skNiwAicBL8TP8PQ@public.gmane.org>
2011-10-31 6:49 ` Pandita, Vikram
2011-10-31 6:49 ` Pandita, Vikram
2011-08-31 0:56 ` Ming Lei
2011-08-31 0:56 ` Ming Lei
2011-09-01 23:16 ` Grant Grundler
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=1314798215.2344.76.camel@deneb.redhat.com \
--to=msalter@redhat.com \
--cc=B29397@freescale.com \
--cc=greg@kroah.com \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-omap@vger.kernel.org \
--cc=linux-usb@vger.kernel.org \
--cc=linux@arm.linux.org.uk \
--cc=ming.lei@canonical.com \
--cc=stern@rowland.harvard.edu \
--cc=will.deacon@arm.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.