Messages in this thread | ![/](/images/icornerl.gif) | | Date | Tue, 20 Jan 2009 10:22:56 -0500 | From | Vivek Goyal <> | Subject | Re: [PATCH]: add dmesg log symbols to /proc/vmcoreinfo lists |
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On Tue, Jan 20, 2009 at 10:09:58AM -0500, Neil Horman wrote: > On Tue, Jan 20, 2009 at 09:15:51AM -0500, Vivek Goyal wrote: > > On Mon, Jan 19, 2009 at 04:21:27PM -0500, Neil Horman wrote: > > > Hey all- > > > It would be nice to be able to extract the dmesg log from a vmcore file > > > without needing to keep the debug symbols for the running kernel handy all the > > > time. We have a facility to do this in /proc/vmcore. This patch adds the > > > log_buf and log_end symbols to the vmcoreinfo area so that tools (like > > > makedumpfile) can easily extract the dmesg logs from a vmcore image. > > > > > > > It would be nice to get dmesg log if debug symbols are not around. Can't > > we use System.map for getting symbol addresses? vmcoreinfo had started > > small and seems to be growing now. I am thinking down the line will making > > use of System.map for such cases make sense? > > > > System.map only include exported and public symbols. log_buf and log_end are > static, and not reported in the System.map. Its a nice idea, but not > comprehensive for everything in the kernel. > > ><snip> > > > > Will it be an issue if we make log_buf and log_end non static and directly > > access these in kexec.c? > > > I had considered that, but was a bit hesitant to do so, since it exposes the > internal implementation of the dmesg buffer. In the event someone disables > CONFIG_PRINTK, thats just more code we need to ifdef. With this implementation > we just stub out the log_buf_setup function, and let that be that. It seems > more consice to me this way. >
Makes sense to me.
Acked-by: Vivek Goyal <vgoyal@redhat.com>
Thanks Vivek
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