From: Benjamin Herrenschmidt <benh@kernel•crashing.org>
To: Nishanth Aravamudan <nacc@us•ibm.com>
Cc: linuxppc-dev@lists•ozlabs.org,
Anton Blanchard <anton@au1•ibm.com>,
Paul Mackerras <paulus@samba•org>,
Robert Jennings <rcj@linux•vnet.ibm.com>
Subject: Re: [PATCH] powerpc/prom: bump up maximum size of properties
Date: Mon, 27 Feb 2012 10:22:14 +1100 [thread overview]
Message-ID: <1330298534.20389.53.camel@pasglop> (raw)
In-Reply-To: <1330129422-2648-1-git-send-email-nacc@us.ibm.com>
On Fri, 2012-02-24 at 16:23 -0800, Nishanth Aravamudan wrote:
> On a 16TB system (using AMS/CMO), I get:
>
> WARNING: ignoring large property [/ibm,dynamic-reconfiguration-memory] ibm,dynamic-memory length 0x000000000017ffec
>
> and significantly less memory is thus shown to the partition. As far as
> I can tell, the constant used is arbitrary, but bump it up to 2MB, which
> covers the above property (approximately 1.5MB).
>
> With this patch, the kernel does see all of the system memory on the
> 16TB system.
Why not go all the way to either removing the limit, or setting it to
something much bigger ? That's just asking to break again when we get an
even bigger system.
The limit was originally set because of Apple machines carrying ROM
images in the device-tree, at a time where we were much more memory
constrained than we are now.
But even then, it never represented such a large gain and in the end,
was probably not -that- useful.
I'd say bump it to something really large like 16M or remove the limit
alltogether.
Cheers,
Ben.
> Signed-off-by: Nishanth Aravamudan <nacc@us•ibm.com>
> Cc: Anton Blanchard <anton@au1•ibm.com>
> Cc: Paul Mackerras <paulus@samba•org>
> Cc: Robert Jennings <rcj@linux•vnet.ibm.com>
> Cc: linuxppc-dev@lists•ozlabs.org
> ---
> arch/powerpc/kernel/prom_init.c | 2 +-
> 1 files changed, 1 insertions(+), 1 deletions(-)
>
> diff --git a/arch/powerpc/kernel/prom_init.c b/arch/powerpc/kernel/prom_init.c
> index eca626e..0bf0ccc 100644
> --- a/arch/powerpc/kernel/prom_init.c
> +++ b/arch/powerpc/kernel/prom_init.c
> @@ -53,7 +53,7 @@
> * ensure that we don't lose things like the interrupt-map property
> * on a PCI-PCI bridge.
> */
> -#define MAX_PROPERTY_LENGTH (1UL * 1024 * 1024)
> +#define MAX_PROPERTY_LENGTH (2UL * 1024 * 1024)
>
> /*
> * Eventually bump that one up
next prev parent reply other threads:[~2012-02-26 23:22 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-02-25 0:23 [PATCH] powerpc/prom: bump up maximum size of properties Nishanth Aravamudan
2012-02-26 23:22 ` Benjamin Herrenschmidt [this message]
2012-02-27 18:55 ` [PATCH] powerpc/prom: remove limit on " Nishanth Aravamudan
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