netdev - Re: understanding linux cache and free command

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [day] [month] [year] [list]

Message-ID: <512D9B28.205@gmail.com>
Date:	Wed, 27 Feb 2013 11:05:36 +0530
From:	Prashant Batra <prbatra.mail@...il.com>
To:	Prashant Batra <prbatra.lists@...il.com>, netdev@...r.kernel.org
CC:	linux-newbie@...r.kernel.org
Subject: Re: understanding linux cache and free command

Adding netdev for a bigger audience.

On Tuesday, February 26, 2013 6:18:48 PM, Prashant Batra wrote:
> Hi All,
>
> I have created few memory cache areas using "kmem_cache_create" and
> using it to allocate some memory.
>
> What I observe after some cache_alloc's and cache_free's is that
> /proc/slabinfo entries for my objects are good, meaning the number of
> objects go back to 0 after they are freed.
>
> But linux "free" command shows that some of the objects are cached and
> that keeps on increasing. I am not able to understand this behavior.
> Is it that kernel keeps the cache objects even after they are freed?
>
> #cat /proc/slabinfo
> my_cache         200    200   4096    1    1 : tunables   24   12    8
> : slabdata    200    200      0
>
> It shows 200 allocated objects from "my_cache"
>
> and
>
> #free -lm
>
>             total       used       free     shared    buffers     cached
> Mem:         48340        610      47730          0         96       130
>
> the cached objects keep on growing.
>
> After 5 mins in which I am doing some alloc and free-
>             total       used       free     shared    buffers     cached
> Mem:        48340        616      47723          0         96        137
>
> /proc/slabinfo remains the same.
>
> Any help is appreciated.
>
> Thanks,
> Prashant


--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html