Re: [PATCH 02/31] perf tools: Don't set cmdline_group_boundary if no evsel is collected

From: Wangnan (F)
Date: Tue Sep 01 2015 - 08:49:11 EST

On 2015/9/1 18:38, Jiri Olsa wrote:
On Mon, Aug 31, 2015 at 04:20:03PM -0300, Arnaldo Carvalho de Melo wrote:
Em Sat, Aug 29, 2015 at 04:21:36AM +0000, Wang Nan escreveu:
If parse_events__scanner() collects no entry, perf_evlist__last(evlist)
is invalid. Then setting of cmdline_group_boundary touches invalid.

It could happend in currect BPF implementation. See [1]. Although it
can be fixed, for safety reason it whould be better to introduce this

Instead of checking number of entries, check data.list instead, so we
can add dummy evsel here.
Event parsing fixes should have Jiri Olsa on the CC list, Jiri, is this

From what I can see it looks Ok, my question, just from looking at this
patch, is if it is valid to get to this point with an empty data.list,
i.e. was it ever possible and this is a bug irrespective of eBPF?
good point, I believe it's either fail or event(s) added to the list
I haven't checked how's eBPF connected with event parsing, is there a
git tree I could check?

Please check:

commit d7d91228cad0a78eae5ea9526a8a78debf3cf584
commit 2606fe61219899cb386823eddc1bc231ff5067a6

related to parsing.

Thank you.


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