On Friday 07 April 2017 06:06 PM, Michael Ellerman wrote:
Sachin Sant <sach...@linux.vnet.ibm.com> writes:
I have run into few instances where the lost_exception_test from
powerpc kselftest fails with SIGABRT. Following o/p is against
4.11.0-rc5. The failure is intermittent.
What hardware are you on?
How long does it take to run when it fails? I assume ~2 minutes?
Started a run in power8 host (habanero) and it is more than 24hrs and
havent failed yet. So this should be guest/VM scenario then?
When the test fails it is killed due to SIGABRT.
# ./lost_exception_test
test: lost_exception
tags: git_version:unknown
Binding to cpu 8
main test running as pid 9208
EBB Handler is at 0x10003dcc
!! killing lost_exception
This is the parent (test harness saying) it's about to kill the child,
because it took too long.
It sends SIGTERM, but the child catches that, prints all this info, and
then aborts() - so that's why you're seeing SIGABRT.
ebb_state):
ebb_count = 191529
The test usually runs until it's taken 1,000,000 EBBs, so it looks like
we got stuck.
spurious = 0
negative = 0
no_overflow = 0
pmc[1] count = 0x0
pmc[2] count = 0x0
pmc[3] count = 0x0
pmc[4] count = 0x4c1b707
We use a varying sample period of between 400 and 600, and from above
we've taken 191,529 EBBs.
0x4c1b707 / 191,529 ~= 416
So that looks reasonable.
pmc[5] count = 0x0
pmc[6] count = 0x0
HW state:
MMCR0 0x0000000080000080 FC PMAO
But this says we're stopped with counters frozen and an event pending.
MMCR2 0x0000000000000000
EBBHR 0x0000000010003dcc
BESCR 0x8000000100000000 GE PMAE
And that says we have global enable set and events enabled.
So I think there is a bug here somewhere. I don't really have time to
dig into it now, neither does Maddy I think. But we should try and get
to it at some point.
cheers
