From: Mauro Carvalho Chehab <mchehab@redhat.com>
To: Jonathan Corbet <corbet@lwn.net>
Cc: Alessandro Rubini <rubini@gnudd.com>,
federico.vaga@gmail.com, m.szyprowski@samsung.com,
mchehab@infradead.org, pawel@osciak.com, hans.verkuil@cisco.com,
giancarlo.asnaghi@st.com, linux-media@vger.kernel.org,
linux-kernel@vger.kernel.org, s.nawrocki@samsung.com
Subject: Re: [PATCH v3 2/4] videobuf2-dma-streaming: new videobuf2 memory allocator
Date: Mon, 7 Jan 2013 18:15:00 -0200 [thread overview]
Message-ID: <20130107181500.24c56803@redhat.com> (raw)
In-Reply-To: <20130107124050.3fc5031b@lwn.net>
Em Mon, 7 Jan 2013 12:40:50 -0700
Jonathan Corbet <corbet@lwn.net> escreveu:
> On Mon, 7 Jan 2013 00:09:47 +0100
> Alessandro Rubini <rubini@gnudd.com> wrote:
>
> > I don't expect you'll see serious performance differences on the PC. I
> > think ARM users will have better benefits, due to the different cache
> > architecture. You told me Jon measured meaningful figures on a Marvel
> > CPU.
>
> It made the difference between 10 frames per second with the CPU running
> flat out and 30fps mostly idle. I think that probably counts as
> meaningful, yeah...:)
Couldn't this performance difference be due to the usage of GFP_DMA inside
the VB2 code, like Federico's new patch series is proposing?
If not, why are there a so large performance penalty?
Regards,
Mauro
next prev parent reply other threads:[~2013-01-07 20:15 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-09-24 10:58 [PATCH v3 1/4] v4l: vb2: add prepare/finish callbacks to allocators Federico Vaga
2012-09-24 10:58 ` [PATCH v3 2/4] videobuf2-dma-streaming: new videobuf2 memory allocator Federico Vaga
2012-09-24 12:44 ` Marek Szyprowski
2012-12-04 16:04 ` Mauro Carvalho Chehab
2012-12-05 12:50 ` Federico Vaga
2012-12-05 14:25 ` Mauro Carvalho Chehab
2012-12-11 13:54 ` Federico Vaga
2012-12-18 14:41 ` Marek Szyprowski
2012-12-20 15:37 ` Federico Vaga
2013-01-01 12:52 ` Mauro Carvalho Chehab
2013-01-03 16:13 ` Federico Vaga
2013-01-04 13:30 ` Federico Vaga
2013-01-06 17:04 ` Federico Vaga
2013-01-06 23:09 ` Alessandro Rubini
2013-01-07 19:40 ` Jonathan Corbet
2013-01-07 20:15 ` Mauro Carvalho Chehab [this message]
2013-01-08 6:50 ` Marek Szyprowski
2013-01-08 14:31 ` Jonathan Corbet
2013-01-09 7:48 ` Michael Olbrich
2012-09-24 10:58 ` [PATCH v3 3/4] sta2x11_vip: convert to videobuf2 and control framework Federico Vaga
2012-12-04 16:15 ` Mauro Carvalho Chehab
2012-12-05 1:12 ` Federico Vaga
2012-12-05 11:34 ` Mauro Carvalho Chehab
2012-12-05 12:24 ` Federico Vaga
2012-12-05 13:10 ` Mauro Carvalho Chehab
2012-12-05 13:27 ` Federico Vaga
2012-12-05 13:37 ` Mauro Carvalho Chehab
2012-12-05 13:45 ` Federico Vaga
2012-12-06 18:59 ` Federico Vaga
2012-09-24 10:58 ` [PATCH v3 4/4] adv7180: remove {query/g_/s_}ctrl Federico Vaga
2012-09-24 12:46 ` [PATCH v3 1/4] v4l: vb2: add prepare/finish callbacks to allocators Marek Szyprowski
2012-09-25 15:04 ` Federico Vaga
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