Re: [PATCH 0/2] trace-vmscan-postprocess: fix parsing and output

[Yafang Shao]

On Thu, Sep 5, 2019 at 4:42 AM Daniel Jordan <daniel.m.jordan@xxxxxxxxxx> wrote:
>
> On Tue, Sep 03, 2019 at 11:14:07AM +0000, Florian Schmidt wrote:
> > This patch series updates trace-vmscan-postprocess.pl to work without
> > throwing warnings and errors which stem from updates to several trace
> > points.
>
> Cc Yafang, who made (most of?) these updates.
>

Yes, I made 3481c37ffa1d and 3b775998eca7 but didn't remeber to update
the scripts in the Document directory.
Thanks for improving it.

> > 3481c37ffa1d ("mm/vmscan: drop may_writepage and classzone_idx from
> > direct reclaim begin template") removed "may_writepage" from
> > mm_vmscan_direct_reclaim_begin, and 3b775998eca7
> > ("include/trace/events/vmscan.h: drop zone id from kswapd tracepoints")
> > removed "zid" from mm_vmscan_wakeup_kswapd. The output of
> > mm_vmscan_lru_isolate and mm_vmscan_lru_shrink_active seems to never
> > have matched the format of the trace point output since they were
> > created, or at least for as long as I can tell. Patch 1 aligns the
> > format parsing of the perl script with the current output of the trace
> > points.
>
> Thanks, patch 1 fixes the script for me for all tracepoints you touched.
>
> > In addition, the tables that are printed by the script were not properly
> > aligned any more, so patch 2 fixes the spacing.
>
> Nit, not for Pages Scanned.  With your series I get
>
> Kswapd          Kswapd      Order      Pages     Pages    Pages    Pages
> Instance       Wakeups  Re-wakeup    Scanned    Rclmed  Sync-IO ASync-IO
> kswapd0-175          1          0    253694     253691        3   129896               wake-0=1
>
> > A side remark: parsing the trace output for mm_vmscan_lru_shrink_active
> > has been in the script ever since it was created in 2010, but at no
> > point the parsed output was ever used for anything. I updated the
> > parsing code now, but I wonder if we could just get rid of that part...
>
> I wonder if we shouldn't just get rid of the whole script, it's hard to
> remember to keep in sync with vmscan changes and I can't think of a way to
> remedy that short of having mm regression tests that run this.

There are some similar scripts under tools/perf/scripts/, i.e.
compaction-times.py.
What about intergrating these vmscan scripts into perf/scripts as well ?
Something like vmscan-times.py...

> But your
> patches are an improvement for now.

Agreed.

Thanks
Yafang