linux_dsm_epyc7002/arch/powerpc/perf
Michael Neuling e13e895f84 powerpc/perf: Fix for PMCs not making progress
On POWER7 when we have really small counts left before overflow, we can take a
PMU IRQ, but the PMC gets wound back to just before the overflow.

If the kernel is setting the PMC to a value just before the overflow, we can
get interrupted again without the PMC making any progress (ie another buggy
overflow).  In this case, we can end up making no forward progress, with the
PMC interrupt returning us to the same count over and over.

The below detects when we are making no forward progress (ie. delta = 0) and
then increases the amount left before the overflow.  This stops us from locking
up.

Signed-off-by: Michael Neuling <mikey@neuling.org>
Reviewed-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
cc: Paul Mackerras <paulus@samba.org>
cc: Anton Blanchard <anton@samba.org>
cc: Linux PPC dev <linuxppc-dev@ozlabs.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-01-10 17:02:04 +11:00
..
callchain.c powerpc/perf: Use perf_instruction_pointer in callchains 2012-07-10 19:18:46 +10:00
core-book3s.c powerpc/perf: Fix for PMCs not making progress 2013-01-10 17:02:04 +11:00
core-fsl-emb.c perf: Pass last sampling period to perf_sample_data_init() 2012-05-09 15:23:12 +02:00
e500-pmu.c powerpc/perf: Add stalled-cycles events 2013-01-10 17:00:56 +11:00
Makefile powerpc/perf: Move perf core & PMU code into a subdirectory 2012-02-23 10:50:04 +11:00
mpc7450-pmu.c powerpc/perf: Move perf core & PMU code into a subdirectory 2012-02-23 10:50:04 +11:00
power4-pmu.c powerpc/perf: Fix instruction address sampling on 970 and Power4 2012-03-28 11:33:24 +11:00
power5-pmu.c powerpc/perf: Move perf core & PMU code into a subdirectory 2012-02-23 10:50:04 +11:00
power5+-pmu.c powerpc/perf: Move perf core & PMU code into a subdirectory 2012-02-23 10:50:04 +11:00
power6-pmu.c powerpc/perf: Move perf core & PMU code into a subdirectory 2012-02-23 10:50:04 +11:00
power7-pmu.c powerpc/perf: Add missing L2 constraint handling in Power7 PMU 2012-11-15 13:00:36 +11:00
ppc970-pmu.c powerpc/perf: Fix instruction address sampling on 970 and Power4 2012-03-28 11:33:24 +11:00