From mboxrd@z Thu Jan  1 00:00:00 1970
From: Benjamin King <benjaminking@web.de>
Subject: Re: How to sample memory usage cheaply?
Date: Sat, 1 Apr 2017 18:27:38 +0200
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To: Vince Weaver <vincent.weaver@maine.edu>
Cc: Milian Wolff <milian.wolff@kdab.com>, linux-perf-users@vger.kernel.org

Hi Vince,

>> Also, the 'perf stat' output that I sent does not make much sense to me right
>> now. For example, when I add MAP_POPULATE to the flags for mmap, I only see
>> ~40 minor page faults, which I do not understand at all.
>
>have you tried accessing your file in random order?  I think the kernel is
>likely doing some sort of readahead/prefetching.  I think you can change
>that behavior with the madvise() syscall

No, I did not try that. Just reading in every 4096th byte. I did assume that
any way of populating the page table of my process would show up as a page
fault. I guess, I have to read a bit more on that...

Cheers,
  Benjamin