On Tue, 17 May 2011 12:30:58 -0500, Nathan D Miller wrote: > Hello- > > Has anyone tried reconstituting a portion of the old kernel's /proc > while in the capture kernel? > > I had the idea while digging through the kexec/kdump code and it seemed > intriguing. > > It might be a means by which user-space dump applications running under > the capture kernel could interrogate the old system, and identify bad > processes that instigated the panic. In particular, I'm thinking of Out > Of Memory scenarios. We've modified our kernel to panic instead of > invoking the kernel's OOM killer, but we still have the problem of > identifying the "bad" process while running in the capture kernel. > > Perhaps everything could be accomplished using some sort of FUSE > file-system around /proc/oldmem and /proc/vmcore. Not all the > proc/<pid>/ files would need to be implemented, of course. In addition, > each old process could have its own 'vmcore' file for getting a core > dump of the original process. > Well, actually you don't need to bother the old /proc to find which process is the killer. The old dmesg contains the PID/comm of the killer process, and we have a tool named vmcore-dmesg to read out the dmesg from the vmcore. With the utility 'crash', you can query any info of any process in the old kernel, so why do you need a per-process vmcore anyway? Thanks.
