Messages in this thread | | | Date | Tue, 5 Jun 2012 21:04:04 +0200 | Subject | Re: git bisect and perf | From | Stephane Eranian <> |
| |
On Tue, Jun 5, 2012 at 7:12 PM, David Ahern <dsahern@gmail.com> wrote: > On 6/5/12 10:05 AM, Peter Zijlstra wrote: >> >> On Tue, 2012-06-05 at 18:00 +0200, Peter Zijlstra wrote: >>> >>> On Tue, 2012-06-05 at 09:29 -0600, David Ahern wrote: >>>> >>>> I am trying find out when (ie. which commit) the pebs feature >>>> actually >>>> started working on a westmere system >>> >>> >>> What do you mean with working? The whole cycles:pp thing is magic and >>> unrelated to 'regular' PEBS stuff. > > > :p requires PEBS? > > >> .35 would indeed be the version we >>> >>> introduced PEBS support and it should actually work. > > > I'm referring to cycles:p > > model name : Intel(R) Xeon(R) CPU E5620 @ 2.40GHz That's not as helpful as /proc/cpuinfo. I suspect this is a Westmere system, isn't it?
> Fedora 14, 2.6.35.14-106.fc14.x86_64 (few perf_event* differences from > 2.6.35.14). > > # perf record -e cycles:p -v -- sleep 1 > > Warning: ... trying to fall back to cpu-clock-ticks > > ... > > Cycles is supported; it's the :p that is not. perf userspace only recently > gained the knowledge for discriminating the two. Using perf from > acme/perf/urgent: > > # /tmp/pbuild/perf record -e cycles:p -v -- sleep 1 > > Error: sys_perf_event_open() syscall returned with 28 (No space left on > device). /bin/dmesg may provide additional information. > > I chased this to intel_pebs_constraints() returning &emptyconstraint which > has a weight of 0 (validate_event -> intel_get_event_constraints -> > intel_pebs_constraints). > > > >>> >>> But if you're looking for the cycles:pp stuff (commit 7639dae0ca1) >>> that's .38-rc1-ish. >> >> >> So on kernels pre that commit you could still do: >> >> perf record -e r108000c0:pp > > > Indeed that works on the F14 kernel. > > David -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
| |