On Mon, Jul 1, 2013 at 8:53 PM, David Ahern <dsah...@gmail.com> wrote: > > On 7/1/13 3:32 AM, Adrian Hunter wrote: >> >> Snip >> >>> >>> While this works for a combined S/W and tracepoint events session, I do not >>> like promoting sample types to the minimum compatible level for all events >>> in the session. perf needs to allow each event to have its own sample_type >>> and not force a minimal compatibility. >> >> >> Why? The impact is small. The kernel API is completely unchanged. > > > I'd like to see libperf become a stable, usable library - usable by more than > the perf binary and its builtin commands. I have already done this once for a > daemon, and it was a PITA to get the specific use functional without memory > leaks/growth in the libperf part. > > With respect to this specific patch it means appropriate flexibility in the > data collected for events. ie., each event can have its own sample_type. For > example if the tracepoint already contains task information TID is not needed > - and IP may not be wanted either. The code processing the samples should not > require all events to have some minimum data format - that just wastes buffer > space. > I agree. This kernel needs to allow for any bit combination on sample_type and yet provide enough info to parse the buffer in the case of multi-event sampling. This is kernel bug. Tools should not have to handle this. Because it'd have to be repeated for each tool.
Later this week, I'll post a patch that address the kernel limitation. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
