Re: [Crash-utility] kmem -[sS] segfault on 2.6.25.17
----- "Mike Snitzer" <snitzer(a)gmail.com> wrote:
I'm getting a core when I try to show slab data (kmem -[sS]) on
2.6.25.17 with both a live crash or saved vmcore.
The core shows that the segv is coming from memset() via
gather_cpudata_list_v2_nodes (memory.c:10119). This is with crash
4.0-7.4, but the same crash occurs with crash 4.0-6.3
(memory.c:10108)
and older.
I've also seen kmem -[sS] segfaults with older kernels too (e.g.
2.6.22.x).
Have others experienced this? Would it be useful for me to provide
my
kernel config?
No that won't help.
It's failing in the BZERO() here:
10117 for (i = 0; (i < ARRAY_LENGTH(kmem_cache_s_array)) &&
10118 (cpudata[i]) && !(index); i++) {
10119 BZERO(si->cpudata[i], sizeof(ulong) * vt->kmem_max_limit);
What is "i" equal to when it segfaults? If you have a crash core file,
print out the contents of the global "vm_table". In that structure
there is a "kmem_max_cpus" field. If "i" is greater or equal to
that,
then that's one explanation.
Or you can bring up the dumpfile (or live system), and look at the value
kmem_max_cpus by looking at the output of "help -v".
Dave
Dave