On Mon, May 09, 2011 at 08:39:02AM -0400, Vivek Goyal wrote: > On Fri, May 06, 2011 at 10:24:12PM +0530, K.Prasad wrote: > > Hi All, > > I wanted to test the behaviour of kdump when panic is triggered > > due to MCE on x86 and found that kdump is not captured. > > > > While the kdump service is configured and running and non-MCE panics > > (such as those triggered through to /proc/sysrq-trigger) successfully > > capture a kdump, any fatal MCE error injected through the mce-inject > > tool causes a reboot of the machine. > > > > The code has been traced (using early_serial_putc()) to enter the kexec > > path i.e. panic()->crash_kexec()->machine_kexec()->relocate_kernel() > > but is untraceable further. > > > > Kdump works fine when the same the similar test is carried out inside a > > KVM guest. > > > > Has anybody tested this before? Or have found kdump working when fatal > > MCEs have actually occurred? > > Prasad, > > I have never tried taking dump in MCE situation. Does kdump work on this > machine with normal panic()? > Hi Vivek, kdump worked fine on this machine for non-MCE triggered panic calls (the /proc/sysrq-trigger initiated crashes got the kdump fine). > Use --debug and --serial option in kexec-tools to print some debug message > and look for "I am in purgatory". This will tell you whether you hanged > in first kernel or second kernel. > There were no boot logs from the second kernel while the "Rebooting in X seconds..." message had appeared before the system rebooted, suggesting that the second kernel did not boot at all. > Then put "outb()" messages in the kernel to trace what happened. > The outb logs showed that the system entered machine_kexec function (traceable upto relocate_kernel) but then rebooted from inside the panic() function. Thanks, K.Prasad
