On 1/31/2018 8:15 AM, Jiri Olsa wrote:
On Wed, Jan 31, 2018 at 10:15:39AM +0100, Jiri Olsa wrote:
On Tue, Jan 30, 2018 at 07:59:41PM -0800, Andi Kleen wrote:
Still, the part I am missing here, is why asking for
PERF_SAMPLE_PERIOD voids large PEBS.
I think it was disabled together with frequency mode
(which we could support too, but it's a bit more work)
But yes PERIOD could probably be allowed.
looks like it's just a matter of adding PERF_SAMPLE_PERIOD
into PEBS_FREERUNNING_FLAGS, we already populate period
in setup_pebs_sample_data
jirka
---
diff --git a/arch/x86/events/perf_event.h b/arch/x86/events/perf_event.h
index 8e4ea143ed96..78f91ec1056e 100644
--- a/arch/x86/events/perf_event.h
+++ b/arch/x86/events/perf_event.h
@@ -93,7 +93,8 @@ struct amd_nb {
PERF_SAMPLE_ID | PERF_SAMPLE_CPU | PERF_SAMPLE_STREAM_ID | \
PERF_SAMPLE_DATA_SRC | PERF_SAMPLE_IDENTIFIER | \
PERF_SAMPLE_TRANSACTION | PERF_SAMPLE_PHYS_ADDR | \
- PERF_SAMPLE_REGS_INTR | PERF_SAMPLE_REGS_USER)
+ PERF_SAMPLE_REGS_INTR | PERF_SAMPLE_REGS_USER | \
+ PERF_SAMPLE_PERIOD)
seems to work, getting large PEBS event for following command line:
perf record -e cycles:P -c 100 --no-timestamp -C 0 --period
Yes, I tried the patch. The large PEBS can be enabled with the PERIOD
flag. Everything looks good.
Jirka, could you please post the patch as well?
Thanks,
Kan
