From mboxrd@z Thu Jan 1 00:00:00 1970 From: Simon Horman Date: Fri, 12 Sep 2008 23:35:02 +0000 Subject: Re: [PATCH]IA64: do not include uncached memory to vmcore Message-Id: <20080912233500.GF3832@verge.net.au> List-Id: References: <48CACCBA.9030905@sgi.com> In-Reply-To: <48CACCBA.9030905@sgi.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Jay Lan Cc: "linux-ia64@vger.kernel.org" , kexec@lists.infradead.org On Fri, Sep 12, 2008 at 01:10:34PM -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 may MCA when it tries to save the vmcore to a disk. > A normal "cached" access can cause MCAs. > > Since kexec assembled memory ranges with memory tagged as "System RAM", > the uncached memory will be excluded if it is labeled differently. > > Simon, since only IA64 will create "Uncached RAM" label, i do not > make changes to other arch. > > Our HP machine in the lab is dead. I am sorry that i can not test > against other IA64 systems (than SGI's). Feedback is very much > appreciated. > > The corresponding kernel patch is needed to test this kexec patch: > http://marc.info/?l=linux-ia64&m2122791230130&w=2 > This patch without the kernel patch will have no effect and do no > harm. Hi Jay, both of these patches seem reasonable to me, especially from a kexec point of view. I will try and test them on an HP RX2620 and Intel Tiger 4 and get back to you shortly. -- Simon Horman VA Linux Systems Japan K.K., Sydney, Australia Satellite Office H: www.vergenet.net/~horms/ W: www.valinux.co.jp/en