On Tue, 11 Sep 2007 14:12:00 -0400 Dave Anderson wrote: > Randy Dunlap wrote: > > > > I have the vmcoreinfo patch applied. > > Kernel is 2.6.23-rc3. > > > > The crash debug output is below. Please let me know if you'd like > > me to test without the vmcoreinfo patch or anything else. > > > > --- [snipped] > A few things come to mind. Walking through the debug data above... > > The very first readmem() from the dumpfile is from the kernel symbol > "kernel_config_data", where you can see that it found the CONFIG_HZ and > CONFIG_NR_CPUS values. The next readmem()'s are of "xtime" and then > "init_uts_ns". We don't know what was read from the "xtime" location, > but the utsname data from "init_uts_ns" gets displayed later on here: > > > utsname version: #19 SMP Tue Sep 4 09:52:06 PDT 2007 > > And then the "linux_banner" address of ffffffff80537000 is first > checked for accessibility (OK), and then it is read successfully, > and its contents are displayed here: > > > /proc/version: > > Linux version 2.6.23-rc3 (rddunlap@xxxxxxxxxxxx) (gcc version 4.1.1 20070105 > (Red Hat 4.1.1-52)) #19 SMP Tue Sep 4 09:52:06 PDT 2007 > > The string above from the dumpfile is correlated against the > linux_banner string in the vmlinux file, which is subsequently > displayed here: > > > /boot/vmlinux-2.6.23-rc3: > > Linux version 2.6.23-rc3 (rddunlap@xxxxxxxxxxxx) (gcc version 4.1.1 20070105 > (Red Hat 4.1.1-52)) #22 SMP Thu Sep 6 21:24:54 PDT 2007 > > The utsname data and the linux_banner string from the dumpfile > are from "Tue Sep 4 09:52:06 PDT 2007", whereas the vmlinux file > was built 2 days later at "Thu Sep 6 21:24:54 PDT 2007". I don't > know whether that's the issue or not. Is there a reason that > you are *not* using the same vmlinux that the dumpfile was created > from? Just sorry user error. Sorry to use your time like that and thanks for the intro-to-crash lesson. It's working now as expected. Thanks. > But, for now let's suppose that the two kernels are identical except > for the date in the linux_banner strings. I don't have a 2.6.23 > kernel source tree handy, but at least as of 2.6.22-5, it was still > declared statically like so: > > struct x8664_pda *_cpu_pda[NR_CPUS] __read_mostly; > > Has that changed? Nope. > If not, it would be worth checking a dumpfile with no pages > excluded with makedumpfile. I wouldn't think the in-kernel > part of the vmcoreinfo patches would make a difference, but > I suppose anything's possible. crash works (loads without error) with the vmcore file and one that has all possible pages removed from it using 'makedumpfile'. > But again -- the very first thing to do is make sure that you > are using the exact same vmlinux as was booted/dumped. Very true. Thanks again. --- ~Randy -- Crash-utility mailing list Crash-utility@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/crash-utility
