From: thomas.petazzoni@free-electrons.com (Thomas Petazzoni)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH 1/2] arm: mvebu: increase atomic coherent pool size for armada 370/XP
Date: Thu, 25 Oct 2012 16:09:28 +0200 [thread overview]
Message-ID: <20121025160928.53daf18a@skate> (raw)
In-Reply-To: <201210251346.41596.arnd@arndb.de>
On Thu, 25 Oct 2012 13:46:41 +0000, Arnd Bergmann wrote:
> > Seems like the driver is too lazy and allocates everything coherent
> > to avoid the hassle of doing dma_map/dma_unmap operations when
> > needed, but I haven't looked in details at the driver yet to see if
> > it would be possible to switch those DMA coherent allocations into
> > non-coherent allocations + appropriate calls to the DMA operations.
>
> Using coherent allocations is fine, I was wondering whether they need
> to be atomic or not.
You're raising a good point here: all the dma_pool_alloc()
allocations done by sata_mv are GFP_KERNEL. So why are we having
problems with the /atomic/ coherent pool size? Is it the libata core
that's doing GFP_ATOMIC DMA coherent allocations. It doesn't seem so.
Something's odd.
Thomas
--
Thomas Petazzoni, Free Electrons
Kernel, drivers, real-time and embedded Linux
development, consulting, training and support.
http://free-electrons.com
WARNING: multiple messages have this Message-ID (diff)
From: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
To: Arnd Bergmann <arnd@arndb.de>
Cc: Gregory CLEMENT <gregory.clement@free-electrons.com>,
Jason Cooper <jason@lakedaemon.net>, Andrew Lunn <andrew@lunn.ch>,
linux-arm-kernel@lists.infradead.org,
Olof Johansson <olof@lixom.net>, Ben Dooks <ben-linux@fluff.org>,
Ian Molton <ian.molton@codethink.co.uk>,
Nicolas Pitre <nico@fluxnic.net>,
Lior Amsalem <alior@marvell.com>,
Maen Suleiman <maen@marvell.com>,
Tawfik Bayouk <tawfik@marvell.com>,
Shadi Ammouri <shadi@marvell.com>,
"Eran Ben-Avi" <benavi@marvell.com>,
Yehuda Yitschak <yehuday@marvell.com>,
Nadav Haklai <nadavh@marvell.com>,
Ike Pan <ike.pan@canonical.com>,
Jani Monoses <jani.monoses@canonical.com>,
Chris Van Hoof <vanhoof@canonical.com>,
Dan Frazier <dann.frazier@canonical.com>,
Leif Lindholm <leif.lindholm@arm.com>,
Jon Masters <jcm@redhat.com>, David Marlin <dmarlin@redhat.com>,
Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>,
linux-kernel@vger.kernel.org,
Marek Szyprowski <m.szyprowski@samsung.com>
Subject: Re: [PATCH 1/2] arm: mvebu: increase atomic coherent pool size for armada 370/XP
Date: Thu, 25 Oct 2012 16:09:28 +0200 [thread overview]
Message-ID: <20121025160928.53daf18a@skate> (raw)
In-Reply-To: <201210251346.41596.arnd@arndb.de>
On Thu, 25 Oct 2012 13:46:41 +0000, Arnd Bergmann wrote:
> > Seems like the driver is too lazy and allocates everything coherent
> > to avoid the hassle of doing dma_map/dma_unmap operations when
> > needed, but I haven't looked in details at the driver yet to see if
> > it would be possible to switch those DMA coherent allocations into
> > non-coherent allocations + appropriate calls to the DMA operations.
>
> Using coherent allocations is fine, I was wondering whether they need
> to be atomic or not.
You're raising a good point here: all the dma_pool_alloc()
allocations done by sata_mv are GFP_KERNEL. So why are we having
problems with the /atomic/ coherent pool size? Is it the libata core
that's doing GFP_ATOMIC DMA coherent allocations. It doesn't seem so.
Something's odd.
Thomas
--
Thomas Petazzoni, Free Electrons
Kernel, drivers, real-time and embedded Linux
development, consulting, training and support.
http://free-electrons.com
next prev parent reply other threads:[~2012-10-25 14:09 UTC|newest]
Thread overview: 43+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-10-24 13:49 [PATCH 0/2] Adding SATA support for Armada 370/XP Gregory CLEMENT
2012-10-24 13:49 ` Gregory CLEMENT
2012-10-24 13:49 ` [PATCH 1/2] arm: mvebu: increase atomic coherent pool size for armada 370/XP Gregory CLEMENT
2012-10-24 13:49 ` Gregory CLEMENT
2012-10-25 5:29 ` Marek Szyprowski
2012-10-25 5:29 ` Marek Szyprowski
2012-10-25 11:27 ` Arnd Bergmann
2012-10-25 11:27 ` Arnd Bergmann
2012-10-25 11:43 ` Thomas Petazzoni
2012-10-25 11:43 ` Thomas Petazzoni
2012-10-25 13:46 ` Arnd Bergmann
2012-10-25 13:46 ` Arnd Bergmann
2012-10-25 14:09 ` Thomas Petazzoni [this message]
2012-10-25 14:09 ` Thomas Petazzoni
2012-10-30 7:19 ` Marek Szyprowski
2012-10-24 13:49 ` [PATCH 2/2] arm: mvebu: adding SATA support: dt binding and config update Gregory CLEMENT
2012-10-24 13:49 ` Gregory CLEMENT
2012-10-24 14:01 ` Thomas Petazzoni
2012-10-24 14:01 ` Thomas Petazzoni
2012-10-24 14:05 ` Gregory CLEMENT
2012-10-24 14:05 ` Gregory CLEMENT
2012-10-25 13:18 ` Jason Cooper
2012-10-25 13:18 ` Jason Cooper
2012-10-25 13:21 ` Thomas Petazzoni
2012-10-25 13:21 ` Thomas Petazzoni
2012-10-25 13:34 ` Gregory CLEMENT
2012-10-25 13:34 ` Gregory CLEMENT
2012-10-25 13:57 ` Rob Herring
2012-10-25 13:57 ` Rob Herring
2012-10-25 16:00 ` Gregory CLEMENT
2012-10-25 16:00 ` Gregory CLEMENT
2012-10-25 13:35 ` Jason Cooper
2012-10-25 13:35 ` Jason Cooper
2012-10-25 13:53 ` Rob Herring
2012-10-25 13:53 ` Rob Herring
2012-10-25 14:11 ` Gregory CLEMENT
2012-10-25 14:11 ` Gregory CLEMENT
2012-10-25 14:27 ` Rob Herring
2012-10-25 14:27 ` Rob Herring
2012-10-24 14:08 ` Andrew Lunn
2012-10-24 14:08 ` Andrew Lunn
2012-10-24 14:45 ` Gregory CLEMENT
2012-10-24 14:45 ` Gregory CLEMENT
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