fastboot-bounces at lists.linux-foundation.org wrote on 06/15/2009 09:43:02 PM: > Dharmosoth Seetharam <dseetharam at inbox.com> > > Hi, > > I have experimented few things and results are below. > > Case 1) echo 0 > /proc/sys/kernel/panic_on_oops > When BUG/oops occurred it is able to log the diagnostics to > /var/log/messages > and then continue(not switching to dump-saving kernel). > > What I am looking is - I want both the things to be happen. > that is - it should log the appropriate messages in /var/ > log/messsages and > should be able to take kernel dump. when panic_on_oops is not set, it does not call crash_kexec() - change in kexec_should_crash() in kernel/kexec.c > > case 2) In general, When panic has occurred we won't log any type of > messages in > /var/log/messages ... am I right ? > If KEXEC is enabled and dump-saving kernel is loaded then > will switch to it and save the kernel dump. > > I have added the dump_stack() function call in the panic() function > before calling crash_kexec with few seconds of delay. It is behaving > like randomly (ie. some time stack traces are logged in / > var/log/messages and > not for rest of the time) > > What I am looking is - I want to log the appropriate > messages in /var/log/messages > and then switch to dump-saving kernel. > printk messages in /var/log/messages is depends on how fast klogd flushes printk buffer. > case 3) In general, When die/nmi_die called we used to log the > appropriate messages in /var/log/message > and then saving kernel dump will be depends on KEXEC enable > and loading dump-saving kernel. > --- am I right ? > > I have added the delay in die() function with few seconds > before calling crash_kexec() > But I never seen messages logged in /var/log/messages, I can > see those on serial console. > > Here also my intention is want both, ie. log the appropriate > messages in /var/log/messages > and then take the action as per KEXEC enabled. printk write to the console and its buffer, As I said, depends on time for klogd flushes printk buffer. > > > > Please advice me, What we can do to achieve those things. > > Thanks for helping me here. > > > regards, > Seetharam > > > > > > > -----Original Message----- > > From: nhorman at redhat.com > > Sent: Sat, 13 Jun 2009 14:07:36 -0400 > > To: dseetharam at inbox.com > > Subject: Re: /var/log/messages doesn't have crash info when kernel gets > > panic/oops/crash > > > > On Fri, Jun 12, 2009 at 11:01:35PM -0800, Dharmosoth Seetharam wrote: > >> > >> Hi Neil, > >> > >> Thanks for your quick reply. > >> > >> What you have suggested is nice when we got/save crash dump (i.e vmcore) > >> What if we failed to save/capture vmcore info or vmcore is corrupted > >> etc. then we dont get any information > >> regarding the panic/crash/oops at anywhere? > >> > > If the vmcore is corrupted to the point where makedumpfile can't extract > > the > > dmesg log, then its certain that syslog wouldn't have been able to write > > anything to /var/log/messages either. As a last resort you can try run > > strings > > on the corrupted vmcore and see if the dmesg log is still in there > > somewhere. > > > > If you forgot to capture the vmcore, theres not much more help I can give > > you, > > Im afraid. You'll just have to make sure you capture it next time. If > > you only > > need the backtrace, and don't want the rest of the vmcore, you can make > > kdump > > just run makedumpfile --dump-dmesg /proc/vmcore /var/log/oops.txt > > > > Neil > > > > > >> > >> > >> > >> Thanks and Regards > >> > >> Seetharam > >> > >> > >>> -----Original Message----- > >>> From: nhorman at redhat.com > >>> Sent: Fri, 12 Jun 2009 16:05:13 -0400 > >>> To: dseetharam at inbox.com > >>> Subject: Re: /var/log/messages doesn't have crash info when kernel gets > >>> panic/oops/crash > >>> > >>> On Fri, Jun 12, 2009 at 01:25:49AM -0800, Dharmosoth Seetharam wrote: > >>>> Hi, > >>>> > >>>> I have encounter a problem called /var/log/messages does not contain > >>>> any > >>>> information > >>>> on kernel crash dump. > >>>> > >>>> Prior to enabling KEXEC we saw stack traces and bug info etc in > >>>> /var/log/messages. > >>>> After enabling KEXEC feature those info was missed. > >>>> > >>>> How can we get those missed info in /var/log/messages even when KEXEC > >>>> feature is enabled. > >>>> > >>>> Any help will appreciate. > >>>> > >>> run crash on the resultant vmcore file that kexec can produce/save and > >>> get the > >>> dmesg log out of it. > >>> alternatively you can use makedumpfile with the --dump-dmesg log > >>> > >>> Neil > >>> > >>>> > >>>> Thanks and Regards > >>>> Seetharam > >>>> > >>>> ____________________________________________________________ > >>>> Receive Notifications of Incoming Messages > >>>> Easily monitor multiple email accounts & access them with a click. > >>>> Visit http://www.inbox.com/notifier and check it out! > >>>> > >>>> _______________________________________________ > >>>> kexec mailing list > >>>> kexec at lists.infradead.org > >>>> http://lists.infradead.org/mailman/listinfo/kexec > >> > >> ____________________________________________________________ > >> GET FREE SMILEYS FOR YOUR IM & EMAIL - Learn more at > >> http://www.inbox.com/smileys > >> Works with AIM?, MSN? 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