From mboxrd@z Thu Jan 1 00:00:00 1970 From: Steven Rostedt Subject: Re: Very aggressive memory reclaim Date: Mon, 28 Mar 2011 13:42:50 -0400 Message-ID: <20110328174250.GE8529@home.goodmis.org> References: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: linux-kernel@vger.kernel.org, Alexander Viro , linux-fsdevel@vger.kernel.org To: John Lepikhin Return-path: Content-Disposition: inline In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org List-Id: linux-fsdevel.vger.kernel.org [ Add Cc's of those that may help you ] -- Steve On Mon, Mar 28, 2011 at 08:39:29PM +0400, John Lepikhin wrote: > Hello, > > I use high-loaded machine with 10M+ inodes inside XFS, 50+ GB of > memory, intensive HDD traffic and 20..50 forks per second. Vanilla > kernel 2.6.37.4. The problem is that kernel frees memory very > aggressively. > > For example: > > 25% of memory is used by processes > 50% for page caches > 7% for slabs, etc. > 18% free. > > That's bad but works. After few hours: > > 25% of memory is used by processes > 62% for page caches > 7% for slabs, etc. > 5% free. > > Most of files are cached, works perfectly. This is the moment when > kernel decides to free some memory. After memory reclaim: > > 25% of memory is used by processes > 25% for page caches(!) > 7% for slabs, etc. > 43% free(!) > > Page cache is dropped, server becomes too slow. This is the beginning > of new cycle. > > I didn't found any huge mallocs at that moment. Looks like because of > large number of small mallocs (forks) kernel have pessimistic forecast > about future memory usage and frees too much memory. Is there any > options of tuning this? Any other variants? > > Thanks! > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/