Subject: Re: [PATCH] i386: single node SPARSEMEM fix
From: Dave Hansen <haveblue@us.ibm.com>
To: Magnus Damm <magnus@valinux.co.jp>
Cc: Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
       linux-mm <linux-mm@kvack.org>,
       "A. P. Whitcroft [imap]" <andyw@uk.ibm.com>
In-Reply-To: <20050906035531.31603.46449.sendpatchset@cherry.local>
References: <20050906035531.31603.46449.sendpatchset@cherry.local>
Content-Type: text/plain
Date: Wed, 07 Sep 2005 10:28:36 -0700
Message-Id: <1126114116.7329.16.camel@localhost>
Mime-Version: 1.0
Content-Transfer-Encoding: 7bit
Sender: linux-kernel-owner@vger.kernel.org
Content-Length: 1239
Lines: 26

On Tue, 2005-09-06 at 12:56 +0900, Magnus Damm wrote:
> This patch for 2.6.13-git5 fixes single node sparsemem support. In the case
> when multiple nodes are used, setup_memory() in arch/i386/mm/discontig.c calls
> get_memcfg_numa() which calls memory_present(). The single node case with
> setup_memory() in arch/i386/kernel/setup.c does not call memory_present()
> without this patch, which breaks single node support.

First of all, this is really a feature addition, not a bug fix. :)

The reason we haven't included this so far is that we don't really have
any machines that need sparsemem on i386 that aren't NUMA.  So, we
disabled it for now, and probably need to decide first why we need it
before a patch like that goes in.

I actually have exactly the same patch that you sent out in my tree, but
it's just for testing.  Magnus, perhaps we can get some of my testing
patches in good enough shape to put them in -mm so that the non-NUMA
folks can do more sparsemem testing.  

-- Dave

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/