From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail203.messagelabs.com (mail203.messagelabs.com [216.82.254.243]) by kanga.kvack.org (Postfix) with ESMTP id 721806B008A for ; Tue, 14 Dec 2010 15:24:33 -0500 (EST) Subject: Re: [PATCH 16/35] writeback: increase min pause time on concurrent dirtiers From: Peter Zijlstra In-Reply-To: <20252.1292357637@localhost> References: <20101213144646.341970461@intel.com> <20101213150328.284979629@intel.com> <15881.1292264611@localhost> <20101214065133.GA6940@localhost> <14658.1292352152@localhost> <1292352908.13513.376.camel@laptop> <20252.1292357637@localhost> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Date: Tue, 14 Dec 2010 21:24:15 +0100 Message-ID: <1292358255.13513.390.camel@laptop> Mime-Version: 1.0 Sender: owner-linux-mm@kvack.org To: Valdis.Kletnieks@vt.edu Cc: Wu Fengguang , Andrew Morton , Jan Kara , Dave Chinner , Christoph Hellwig , Trond Myklebust , Theodore Ts'o , Chris Mason , Mel Gorman , Rik van Riel , KOSAKI Motohiro , Greg Thelen , Minchan Kim , linux-mm , "linux-fsdevel@vger.kernel.org" , LKML List-ID: On Tue, 2010-12-14 at 15:13 -0500, Valdis.Kletnieks@vt.edu wrote: > So you're not guaranteed that 10*HZ is 10 seconds. 10*USER_HZ, sure. > But not HZ. You're confused. 10*HZ jiffies is always 10 seconds. Hertz means per-second. We take CONFIG_HZ ticks per second, so waiting HZ jiffies makes us wait 1 second. USER_HZ is archaic and only used to stabilize user-interfaces that for some daft reason depended on HZ. -- 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/ . Fight unfair telecom policy in Canada: sign http://dissolvethecrtc.ca/ Don't email: email@kvack.org