memory consumption information in perf stat?

memory consumption information in perf stat?

[Milian Wolff]

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Hey all,

for user-space profiling, it would be extremely useful to get memory 
consumption information such as peak heap size into the output of perf stat. 
Is this doable? I just learned that `command time -v` is able to output the 
maximum and average RSS. It would be extremely nice if `perf stat` could 
incorporate that as well somehow such that I only need a single application to 
look at that.

If this is doable, then feel free to guide me to the code and I'm willing to 
supply a patch for perf stat.

Thanks
-- 
Milian Wolff | milian.wolff@kdab.com | Software Engineer
KDAB (Deutschland) GmbH&Co KG, a KDAB Group company
Tel: +49-30-521325470
KDAB - The Qt Experts

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Re: memory consumption information in perf stat?

[Manuel Selva]

Hi,

I am not sure perf stat can compute such information because it mainly 
count events (hardware or kernel). To compute the peak heap size, perf 
stat would require the knowledge of all heap memory allocations.

----
Manu

On 28/01/2016 18:11, Milian Wolff wrote:
> Hey all,
>
> for user-space profiling, it would be extremely useful to get memory
> consumption information such as peak heap size into the output of perf stat.
> Is this doable? I just learned that `command time -v` is able to output the
> maximum and average RSS. It would be extremely nice if `perf stat` could
> incorporate that as well somehow such that I only need a single application to
> look at that.
>
> If this is doable, then feel free to guide me to the code and I'm willing to
> supply a patch for perf stat.
>
> Thanks

Re: memory consumption information in perf stat?

[Milian Wolff]

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On Donnerstag, 28. Januar 2016 20:55:05 CET Manuel Selva wrote:
> Hi,
> 
> I am not sure perf stat can compute such information because it mainly
> count events (hardware or kernel). To compute the peak heap size, perf
> stat would require the knowledge of all heap memory allocations.

Right, that is why I compared it to `time -v` which only gives the RSS as a 
ballpark figure which is often useful already to compare before/after. And if 
`time -v` can do it, I'd say `perf stat` should be able to do it as well? To 
track individual heap allocations, I'm using my heaptrack tool anyways. This 
request is more about making `perf stat` more useful by adding another side of 
the performance coin to it.

-- 
Milian Wolff | milian.wolff@kdab.com | Software Engineer
KDAB (Deutschland) GmbH&Co KG, a KDAB Group company
Tel: +49-30-521325470
KDAB - The Qt Experts

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Re: memory consumption information in perf stat?

[Taeung Song]

Hi, Brendan Gregg

I saw your website and your email in LKML
so I sent this mail that contain a question.
(Thanks for your perf example page http://www.brendangregg.com/perf.html )

Would you mind if I ask you a question about perf ?

I saw several questions that can be answered by 'perf' in perf example 
page. 'Which code-paths are allocating memory, and how much?' among 
them. How to get answer of this question ?

I used 'perf mem record/report' and
'perf record -e mem-loads,mem-stores' to get memory information
running my sample program.
But I don't know very well how much is allocated memory
because only mem-* events count or overhead(%), etc can be seen.

Are there another way to check memory consumption info by perf ?

(I looked into perf example page but I mightn't look for the contents 
for it in the page.)
(Sure, I used 'command time -v', 'ps' and other tools in linux
to know this information.)

And I added Cc linux-perf-users and Milian Wolff
because I think this can be related to the mail of Milian.

(If someone would reply, I'd appreciate it.)

Thanks,
Taeung

On 01/29/2016 02:11 AM, Milian Wolff wrote:
> Hey all,
>
> for user-space profiling, it would be extremely useful to get memory
> consumption information such as peak heap size into the output of perf stat.
> Is this doable? I just learned that `command time -v` is able to output the
> maximum and average RSS. It would be extremely nice if `perf stat` could
> incorporate that as well somehow such that I only need a single application to
> look at that.
>
> If this is doable, then feel free to guide me to the code and I'm willing to
> supply a patch for perf stat.
>
> Thanks
>