From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx172.postini.com [74.125.245.172]) by kanga.kvack.org (Postfix) with SMTP id 754986B0031 for ; Mon, 5 Aug 2013 14:24:41 -0400 (EDT) Message-ID: <51FFEDD6.7020906@intel.com> Date: Mon, 05 Aug 2013 11:24:22 -0700 From: Dave Hansen MIME-Version: 1.0 Subject: Re: swap behavior during fast allocation References: In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Luigi Semenzato Cc: linux-mm@kvack.org On 08/05/2013 11:04 AM, Luigi Semenzato wrote: > We can reproduce this by running a few processes that mmap large > chunks of memory, then randomly touch pages to fault them in. We also > think this happens when a process writes a large amount of data using > buffered I/O, and the "Buffers" field in /proc/meminfo exceeds 1GB. > (This is something that can and should be corrected by using > unbuffered I/O instead, but it's a data point.) Where are all the buffers coming from? Most I/O to/from filesystems should be instantiating relatively modest amounts of Buffers. Are you doing I/O directly to devices for some reason? -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org