From mboxrd@z Thu Jan 1 00:00:00 1970 From: Simon Horman Date: Mon, 15 Sep 2008 05:10:51 +0000 Subject: Re: [PATCH]IA64: assign a distinguishable label to uncached memory Message-Id: <20080915051049.GA7369@verge.net.au> List-Id: References: <48C9A2F8.3060308@sgi.com> In-Reply-To: <48C9A2F8.3060308@sgi.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Jay Lan Cc: kexec@lists.infradead.org, Bernhard Walle , Jack Steiner , linux-ia64@vger.kernel.org On Thu, Sep 11, 2008 at 04:00:08PM -0700, Jay Lan wrote: > Currently a memory segment in memory map with attribute of EFI_MEMORY_UC > is denoted as "System RAM" in /proc/iomem, while memory of attribute > (EFI_MEMORY_WB|EFI_MEMORY_UC) is also labeled the same. > > The kexec utility then includes uncached memory as part of vmcore. The > kdump kernel MCA'ed when it tries to save the vmcore to a disk. A normal > "cached" access may cause MCAs. > > This patch would label memory with attribute of EFI_MEMORY_UC only as > "Uncached RAM" so that kexec would know not to include it in the vmcore. > I will submit a separate kexec-tools patch to the kexec list. > > Signed-off-by: Jay Lan Hi Jay, I've taken a look on an RX2620, Tiger2 and Tiger4 and none of these machines have EFI memory regions that are covered by this new check. That is, any regions with the EFI_MEMORY_UC bit set in the attribute either also have other attibute bits set, or are of a type not covered by this. I strongly suspect that this is not a problem, but I wanted to bring it to your attention anyway. I can provide more detailed EFI information from any or all of these machines if you need it. With regards to the kexec-tools portion of this patch, it looks fine to me and I don't think there will be any problem in merging it if/when the kernel portion is accepted. -- Simon Horman VA Linux Systems Japan K.K., Sydney, Australia Satellite Office H: www.vergenet.net/~horms/ W: www.valinux.co.jp/en