Re: [PATCH v3 2/7] perf util: Create streams for managing top N hottest callchains

[Jin, Yao]

Hi Jiri,

On 4/27/2020 6:10 PM, Jiri Olsa wrote:
> On Mon, Apr 20, 2020 at 09:04:46AM +0800, Jin Yao wrote:
> > We think the stream is a callchain which is aggregated by the LBR
> > records from samples. By browsing the stream, we can understand
> > the code flow.
> >
> > The struct callchain_node represents one callchain and we use the
> > callchain_node->hit to measure the hot level of this callchain.
> > Higher is hotter.
> >
> > Since in perf data file, there may be many callchains so we just
> > need to focus on the top N hottest callchains. N is a user defined
> > parameter or just a predefined default value.
> >
> > This patch saves the top N hottest callchains in 'struct stream_node'
> > type array, which is defined in a per event 'struct callchain_streams'.
> >
> > So now we can get the per-event top N hottest callchains.
> >
> >   v2:
> >   ---
> >   Use zfree in free_evsel_streams().
> >
> > Signed-off-by: Jin Yao <yao.jin@xxxxxxxxxxxxxxx>
> > ---
> >   tools/perf/util/callchain.c | 122 ++++++++++++++++++++++++++++++++++++
> >   tools/perf/util/callchain.h |  16 +++++
> >   2 files changed, 138 insertions(+)
>
> SNIP
>
> could this and all the other related code moved to separated object
> like streams.c or such.. I think also the stuff from patch 1 could
> go there, as it's specific only to this streams code
>
> jirka

That's fine. I will move the related codes to a new streams.c/streams.h.

Thanks
Jin Yao