f53d168c02
perf/Power: PERF_EVENT_IOC_ENABLE does not reenable event
If we disable a perf event because we exceeded the specified ->event_limit,
power_pmu_stop() sets the PERF_HES_STOPPED flag on the event.
If the application then re-enables the event using PERF_EVENT_IOC_ENABLE
ioctl, we don't ever clear this STOPPED flag. Consequently, the user space
is never notified of the event.
Following message has more background and test case.
http://lists.eecs.utk.edu/pipermail/ptools-perfapi/2012-October/002528.html
Used the following test cases to verify that this patch works on latest PAPI.
$ papi.git/src/ctests/nonthread PAPI_TOT_CYC@5000000
$ papi.git/src/ctests/overflow_single_event
Changelog[v2]:
- [Paul Mackerras] Also clear PERF_HES_UPTODATE flag since we are
restarting the event; cleanup comments and patch description.
Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
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| .. | ||
| callchain.c | ||
| core-book3s.c | ||
| core-fsl-emb.c | ||
| e500-pmu.c | ||
| Makefile | ||
| mpc7450-pmu.c | ||
| power4-pmu.c | ||
| power5+-pmu.c | ||
| power5-pmu.c | ||
| power6-pmu.c | ||
| power7-pmu.c | ||
| ppc970-pmu.c | ||