From: linux@arm.linux.org.uk (Russell King - ARM Linux)
To: linux-arm-kernel@lists.infradead.org
Subject: too much memory for node
Date: Wed, 20 Jan 2010 16:10:53 +0000 [thread overview]
Message-ID: <20100120161053.GD27507@n2100.arm.linux.org.uk> (raw)
In-Reply-To: <20100120160525.GW10014@trinity.fluff.org>
On Wed, Jan 20, 2010 at 04:05:25PM +0000, Ben Dooks wrote:
> On Wed, Jan 20, 2010 at 03:55:10PM +0000, Russell King - ARM Linux wrote:
> > On Wed, Jan 20, 2010 at 03:34:11PM +0000, Ben Dooks wrote:
> > > I've been looking at support for a new machine type where the
> > > current system is using DISCONTIGMEM as the 1G memory map has
> > > 4x256M RAM ranges which may not all be filled.
> >
> > Firstly, use sparsemem, unless you intentionally want to spend more
> > cycles in the kernel.
>
> Ok, any idea if that will fix the problem in this case?
It _may_ do, because it doesn't have the concept of NUMA nodes (which
is what discontigmem is all about.)
> Should I send a patch to detect bad DISCONTIGMEM setup? I think that
> a check of PHYS_TO_PFN((start+end) != PHYS_TO_PFN(start)) should be
> safe in all cases?
Just move away from discontigmem completely. Sparsemem can do everything
we need on ARM at a lesser cost. As I say above, discontigmem is really
for NUMA platforms, and ARM is not a NUMA platform. No one on ARM should
be going anywhere near discontigmem.
next prev parent reply other threads:[~2010-01-20 16:10 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-01-20 15:34 too much memory for node Ben Dooks
2010-01-20 15:55 ` Russell King - ARM Linux
2010-01-20 16:05 ` Ben Dooks
2010-01-20 16:10 ` Russell King - ARM Linux [this message]
2010-01-25 11:58 ` Ben Dooks
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