On Sun, Oct 20, 2013 at 10:25:31PM -0400, Alex Vanderpol wrote: > Unfortunately I no longer have any of those crash dumps available to > send you anything, I had sent what I had gotten to the kernel > maintainers previously in an attempt to track down the cause of the > crashing, which I don't believe was ever figured out exactly but was > ultimate fixed in a later kernel version. I don't know if they would > still happen to have it on hand or not, though. > > For what it's worth, there never was a vmcore file created any time > I did get a dump, instead I always got two separate files, one which > is the main core dump and one which is supposed to be the dmesg log > dump which unfortunately was never actually able to be dumped (the > issue I filed this bug report about). If the end result is supposed > to be one vmcore file, I suspect the inability of makedumpfile to > dump the kernel dmesg log prohibited it from combining the two files > into one file.
It's always two separate files. They are not meant to be combined - the dmesg dump is just intended for convenience (you can just read the file as text instead of opening a dump with crash). > Using the 'log' command from within crash was ultimately useless as > well, as the kernel log wasn't dumped, therefore there wasn't any > log for crash to open. > > This issue was with kernel 3.11-rc4-amd64 in its stock configuration. Not a Debian package? I'm not sure what you mean when you say stock configuration. Do you mean you ran 'make defconfig' to generate the kernel .config? > I hope what information I am able to give you proves to be at least > somewhat useful. I'm not really sure what you saw. :-/ I'll see if I can reproduce anything with linux-image-3.11-1-amd64_3.11.5-1_amd64 when I have some free time (I lost the VM I use for testing this stuff). It's possible there was a short-lived bug in the kernel itself, causing some corrupt representation of its log buffer. > On 2013-10-20 10:29 PM, John Wright wrote: > >Hi Alex, > > > >On Fri, Aug 16, 2013 at 10:12:39PM -0400, Alex Vanderpol wrote: > >>Package: makedumpfile > >>Version: 1.5.4-1 > >>Severity: grave > >>Justification: renders package unusable > >> > >>Dear Maintainer, > >> > >>There seems to be a serious issue with makedumpfile that causes it to fail > >>to > >>dump the kernel log when collecting crash dump information. Instead, the > >>program continues to run indefinitely, continually appending the line "[ > >>0.000000] " to the file as it seems to attempt to dump the log, which, if > >>left > >>alone for any considerable length of time, can rapidly result in a very > >>large, > >>entirely useless dmesg dump file. > >> > >>I have been trying to collect crash dump information for a crash that's > >>triggered whenever Folding@Home's FahCore_a4 attempts to resume an > >>in-progress > >>work unit, however, every crash dump I've collected has had this problem. > >>The > >>main dump file seems to be dumped without a problem (though crash > >>identifies it > >>as a partial dump, possibly due to the kernel log being dumped into a > >>separate > >>file). > >> > >>I hope you can look into this issue and hopefully it can be sorted out soon. > >Sorry for the long delay in my response. This seems like a serious but > >not actually grave issue, since the core dump does actually exist (even > >though you have to interrupt the dmesg extraction). crash identifies > >the dump as a partial dump because we explicitly ignore zero pages and > >userspace pages. Within crash, you should be able to use the 'log' > >command to get the most recent log messages before the crash...assuming > >crash doesn't break in the same way makedumpfile does. > > > >I will try to reproduce this, but I worry the problem might be somewhat > >specific either to your crash or some other part of your configuration. > >Would you feel comfortable making the vmcore available to me? It would > >also help to know the exact kernel version, and access to a dbg package > >if it's not a stock kernel. > > > >Sorry for the issue and thanks for the report! -- John Wright <j...@debian.org> -- To UNSUBSCRIBE, email to debian-bugs-rc-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org
