2011/5/17 WANG Cong <xiyou.wangcong at gmail.com>: > 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? > If you use one of the latest kernel and gdb you can do it with gdb without crash or vmcore-dmesg. > Thanks. > > > _______________________________________________ > kexec mailing list > kexec at lists.infradead.org > http://lists.infradead.org/mailman/listinfo/kexec > -- Best regards, Maxim Uvarov
