linux-kernel - Re: [BUG?] memory allocation profiling: the counters are not non-decreasing.

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Date: Wed, 5 Jun 2024 13:00:17 -0700
From: Suren Baghdasaryan <surenb@...gle.com>
To: David Wang <00107082@....com>
Cc: kent.overstreet@...ux.dev, keescook@...omium.org, 
	linux-kernel@...r.kernel.org
Subject: Re: [BUG?] memory allocation profiling: the counters are not non-decreasing.

On Wed, Jun 5, 2024 at 5:37 AM David Wang <00107082@....com> wrote:
>
> Hi,
> I was playing with this new feature of memory allocation profiling, when I plot the data, grouped by caller's source dir,
> I noticed that the counters are not non-decreasing.
> If I understand this feature correctly, all counters should be non-decreasing, right?
> Or is there some TTL for stale items?

Hi David,
Counters can decrease once an allocation is freed.
Thanks,
Suren.

>
> Following is a simpler script demonstrating my sayings
>
>         $ for i in {1..100}; do sudo cat /proc/allocinfo | grep " mm\/" | awk '{s+=$2}END{print s}'; sleep 10; done
>         1194453
>         1196935
>         1198957
>         1199716
>         1200770
>         1190795  <--- decrease here
>         1192702
>         1193070
>         1193812
>         1195069
>         1196491
>         ...
>
> FYI
> David
>