Messages in this thread | | | From | Namhyung Kim <> | Subject | Re: [PATCH 03/11] perf tool: Use PERF_EVENT_IOC_ID perf ioctl to read event id | Date | Mon, 22 Oct 2012 16:57:24 +0900 |
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Hi,
Just a minor nitpicking..
On Sat, 20 Oct 2012 16:33:11 +0200, Jiri Olsa wrote: > Changing the way we retrieve the event ID. Instead of parsing out > the ID out of the read data, using the PERF_EVENT_IOC_ID ioctl. > > Keeping the old way in place to support kernels without > PERF_EVENT_IOC_ID ioctl support. [snip] > + } else if (errno) > + return -1;
Is this check really needed? I think that returning non-zero from the ioctl always sets the errno, no? How about this:
ret = ioctl(fd, PERF_EVENT_IOC_ID, &id); if (!ret) goto add;
if (errno != ENOTTY) return -1;
...
I guess that it'll show you better diff stat. :)
Thanks, Namhyung
> > - perf_evlist__id_add(evlist, evsel, cpu, thread, read_data[id_idx]); > + add: > + perf_evlist__id_add(evlist, evsel, cpu, thread, id); > return 0; > }
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