Re: [PATCH] perf record: fix fallback to cpu-clock on ppc

[David Ahern <dsahern@gmail.com>]

On 5/9/12 8:56 AM, Arnaldo Carvalho de Melo wrote:
> Em Mon, May 07, 2012 at 10:40:04PM -0600, David Ahern escreveu:
>> perf-record on PPC is not falling back to cpu-clock:
>>
>> Old kernel, cannot exclude guest or host samples.
>>
>>    Error: sys_perf_event_open() syscall returned with 6 (No such device or address).  /bin/dmesg may provide additional information.
>>
>>    Fatal: No CONFIG_PERF_EVENTS=y kernel support configured?
>>
>> The problem is that until 2.6.37 (behavior changed with commit b0a873e)
>> perf on PPC returns ENXIO when hw_perf_event_init() fails. With this
>> patch we get the expected behavior:
>>
>> Old kernel, cannot exclude guest or host samples.
>> The cycles event is not supported, trying to fall back to cpu-clock-ticks
>> [ perf record: Woken up 1 times to write data ]
>> [ perf record: Captured and wrote 0.150 MB /tmp/perf.data (~6569 samples) ]
>
> Thanks, applied to my perf/core branch.
>
> Can you please provide one for perf/urgent?

Not needed. Problem on perf/core was introduced by 
5a7ed29c7572d00a75e8c4529e30c5ac2ef82271

The perf-stat version is needed and applies cleanly (though with an 
offset) to perf/urgent.

David