Re: [PATCH 1/2] perf script python: integrate page reclaim analyze script

[Yafang Shao]

On Thu, Sep 26, 2019 at 11:36 AM Tony Jones <tonyj@xxxxxxx> wrote:
>
> On 9/25/19 6:56 PM, Tony Jones wrote:
> > On 9/18/19 7:38 AM, Yafang Shao wrote:
> >> A new perf script page-reclaim is introduced in this patch. This new script
> >> is used to report the page reclaim details. The possible usage of this
> >> script is as bellow,
> >> - identify latency spike caused by direct reclaim
> >> - whehter the latency spike is relevant with pageout
> >> - why is page reclaim requested, i.e. whether it is because of memory
> >>   fragmentation
> >> - page reclaim efficiency
> >> etc
> >> In the future we may also enhance it to analyze the memcg reclaim.
> >>
> >> Bellow is how to use this script,
> >>     # Record, one of the following
> >>     $ perf record -e 'vmscan:mm_vmscan_*' ./workload
> >>     $ perf script record page-reclaim
> >>
> >>     # Report
> >>     $ perf script report page-reclaim
> >>
> >>     # Report per process latency
> >>     $ perf script report page-reclaim -- -p
> >
> >
> > I tested it with global-dhp__pagereclaim-performance from mmtests and got what appears to be reasonable results and the output looks correct and useful.  However I'm not a vm expert so I can't comment further.  Hopefully someone on linux-mm can give more specific feedback.
> >
> > There is one issue with Python3,  see below.  I didn't test with Python2.
>
> Ok, I guess this wasn't actually tested with Python3 as itervalues() is Python2 only.   Any scripts need to work with both Python2.6+ and Python3.
>
> # perf script -i /tmp/perf.out -s page-reclaim.py -- -p
> ...
>
> Traceback (most recent call last):
>   File "page-reclaim.py", line 305, in trace_end
>     i.display_proc(),
>   File "page-reclaim.py", line 268, in display_proc
>     print_proc_latency(sorted(self.stat.stats['latency'].itervalues(),
> AttributeError: 'dict' object has no attribute 'itervalues'
> Fatal Python error: problem in Python trace event handler
>
> Use a try/except to handle this.
>

Hi  Tony,

Thanks for your review.
I only verified it with python2.
I will improve it to make it work with both python2.6+ and python3.

Thanks
Yafang