Re: [Crash-utility] Re: [PATCH 0/2] vmcoreinfo support for dump filtering #2

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. > > ---

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(a)unicorn.site) (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(a)unicorn.site) (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?

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?

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.

But again -- the very first thing to do is make sure that you are using the exact same vmlinux as was booted/dumped.