From: arnd@arndb.de (Arnd Bergmann)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH 5/5] arm: dts: Convert mvebu device tree files to 64 bits
Date: Fri, 22 Mar 2013 19:33:16 +0000 [thread overview]
Message-ID: <201303221933.16426.arnd@arndb.de> (raw)
In-Reply-To: <20130322174300.GA10230@obsidianresearch.com>
On Friday 22 March 2013, Jason Gunthorpe wrote:
> At a certain point low mem exhaustion becomes a serious issue for
> Linux, a system that can't DMA to 85% of its memory is incredibly
> broken, IMHO.
A lot of workloads will also suffer from lowmem exhaustion even without
the DMA zone problem. If course the combination is particularly nasty
because now the kernel has a to kmap() a user page in order to copy the
dma data in and out of lowmem.
I'm sure there are even workloads that perform well with more than
16GB, but I can't think of any right now. I would expect that 4 or 8 GB
is where it gets quite silly for most workloads, but troubles start as
soon as you go beyond 1GB.
Arnd
prev parent reply other threads:[~2013-03-22 19:33 UTC|newest]
Thread overview: 33+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-03-21 16:26 [PATCH 0/5] arm: mvebu: Enable LPAE support for Armada XP SoCs Gregory CLEMENT
2013-03-21 16:26 ` [PATCH 1/5] arm: mvebu: Aligne the internal registers virtual base to support LPAE Gregory CLEMENT
2013-03-21 16:26 ` [PATCH 2/5] arm: mvebu: Select DMA_BOUNCE when LPAE is selected in Kconfig Gregory CLEMENT
2013-03-21 18:19 ` Rob Herring
2013-03-21 19:18 ` Andrew Lunn
2013-03-22 11:32 ` Russell King - ARM Linux
2013-03-21 16:26 ` [PATCH 3/5] arm: mvebu: Enable pj4b on LPAE compilations Gregory CLEMENT
2013-03-21 16:26 ` [PATCH 4/5] arm: dts: Add a 64 bits version of the skeleton device tree Gregory CLEMENT
2013-03-21 16:26 ` [PATCH 5/5] arm: dts: Convert mvebu device tree files to 64 bits Gregory CLEMENT
2013-03-21 17:59 ` Rob Herring
2013-03-21 19:03 ` Arnd Bergmann
2013-03-21 19:18 ` Thomas Petazzoni
2013-03-21 21:31 ` Arnd Bergmann
2013-03-21 22:30 ` Sebastian Hesselbarth
2013-03-21 20:15 ` Andrew Lunn
2013-03-21 20:22 ` Thomas Petazzoni
2013-03-21 20:30 ` Jason Cooper
2013-03-21 20:37 ` Andrew Lunn
2013-03-21 21:08 ` Thomas Petazzoni
2013-03-21 21:16 ` Thomas Petazzoni
2013-03-21 20:55 ` Jason Gunthorpe
2013-03-21 21:15 ` Thomas Petazzoni
2013-03-21 21:35 ` Lior Amsalem
2013-03-21 21:46 ` Jason Gunthorpe
2013-03-21 21:58 ` Lior Amsalem
2013-03-22 6:55 ` Arnd Bergmann
2013-03-21 21:41 ` Jason Gunthorpe
2013-03-21 22:26 ` Sebastian Hesselbarth
2013-03-22 9:55 ` Arnd Bergmann
2013-03-21 21:25 ` Andrew Lunn
2013-03-22 6:28 ` Andrew Lunn
2013-03-22 17:43 ` Jason Gunthorpe
2013-03-22 19:33 ` Arnd Bergmann [this message]
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