From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755186Ab0IOT1J (ORCPT ); Wed, 15 Sep 2010 15:27:09 -0400 Received: from e3.ny.us.ibm.com ([32.97.182.143]:44040 "EHLO e3.ny.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753710Ab0IOT1G (ORCPT ); Wed, 15 Sep 2010 15:27:06 -0400 Subject: Re: [RFC][PATCH] update /proc/sys/vm/drop_caches documentation From: Dave Hansen To: "Eric W. Biederman" Cc: KOSAKI Motohiro , KAMEZAWA Hiroyuki , linux-kernel@vger.kernel.org, linux-mm@kvack.org, lnxninja@linux.vnet.ibm.com In-Reply-To: References: <20100914234714.8AF506EA@kernel.beaverton.ibm.com> <20100915133303.0b232671.kamezawa.hiroyu@jp.fujitsu.com> <20100915135016.C9F1.A69D9226@jp.fujitsu.com> <1284531262.27089.15725.camel@nimitz> Content-Type: text/plain; charset="ANSI_X3.4-1968" Date: Wed, 15 Sep 2010 12:27:01 -0700 Message-ID: <1284578821.27089.17409.camel@nimitz> Mime-Version: 1.0 X-Mailer: Evolution 2.28.1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 2010-09-15 at 11:37 -0700, Eric W. Biederman wrote: > > I'm worried that there are users out there experiencing real problems > > that aren't reporting it because "workarounds" like this just paper over > > the issue. > > For what it is worth. I had a friend ask me about a system that had 50% > of it's memory consumed by slab caches. 20GB out of 40GB. The kernel > was suse? 2.6.27 so it's old, but if you are curious. > /proc/sys/vm/drop_caches does nothing in that case. Was it the reclaimable caches doing it, though? The other really common cause is kmalloc() leaks. -- Dave