From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jay Lan Date: Tue, 08 Apr 2008 18:19:00 +0000 Subject: Re: [PATCH 1/2] ia64 kdump: add kdump_on_fatal_mca Message-Id: <47FBB714.6050707@sgi.com> List-Id: References: <47FAF533.8010707@jp.fujitsu.com> In-Reply-To: <47FAF533.8010707@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-ia64@vger.kernel.org Luck, Tony wrote: >> I think kdump_on_fatal_mca should be set to 1 by default. Fatal >> mca is exactly the case where we need a dump to analyze the problem. > > I'm not so sure. If the fatal MCA was caused by the s/w doing something > wrong (e.g. accessing non-existant memory), then a dump is useful to find out > what went wrong. > > But if the MCA was caused by some h/w error (e.g. 2xECC bit error in kernel > memory), then a dump won't help. > > Perhaps the dump would help distinguish the s/w case from the h/w case? With a dump, certainly it would be very clear, but that is not the point. When one puts aside a big chunk of memory for crashkernel. i think he would like to get the dump when kernel crashes. Trying to recreate a kernel crash on a large production system is expensive and sometimes not that readily reproducible. Taking a dump on fatal MCA is the (default) bahavior today, isn't it? - jay > > -Tony > -- > To unsubscribe from this list: send the line "unsubscribe linux-ia64" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html