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From: Prashant Batra <prbatra.lists@gmail.com>
To: linux-newbie@vger.kernel.org
Cc: prbatra.mail@gmail.com
Subject: understanding linux cache and free command
Date: Tue, 26 Feb 2013 18:18:48 +0530	[thread overview]
Message-ID: <512CAF30.70805@gmail.com> (raw)

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
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next             reply	other threads:[~2013-02-26 12:48 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-02-26 12:48 Prashant Batra [this message]
2013-02-27  5:35 ` understanding linux cache and free command Prashant Batra

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