From mboxrd@z Thu Jan 1 00:00:00 1970 From: Prashant Batra Subject: Re: understanding linux cache and free command Date: Wed, 27 Feb 2013 11:05:36 +0530 Message-ID: <512D9B28.205@gmail.com> References: <512CAF30.70805@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Cc: linux-newbie@vger.kernel.org To: Prashant Batra , netdev@vger.kernel.org Return-path: Received: from mail-pb0-f46.google.com ([209.85.160.46]:46446 "EHLO mail-pb0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752091Ab3B0Ffl (ORCPT ); Wed, 27 Feb 2013 00:35:41 -0500 In-Reply-To: <512CAF30.70805@gmail.com> Sender: netdev-owner@vger.kernel.org List-ID: 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