From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail144.messagelabs.com (mail144.messagelabs.com [216.82.254.51]) by kanga.kvack.org (Postfix) with SMTP id D60E86B003D for ; Thu, 26 Feb 2009 12:40:14 -0500 (EST) Received: from localhost (smtp.ultrahosting.com [127.0.0.1]) by smtp.ultrahosting.com (Postfix) with ESMTP id 2F1A482C7A9 for ; Thu, 26 Feb 2009 12:45:05 -0500 (EST) Received: from smtp.ultrahosting.com ([74.213.175.254]) by localhost (smtp.ultrahosting.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id RWi6f+k16Unm for ; Thu, 26 Feb 2009 12:45:05 -0500 (EST) Received: from qirst.com (unknown [74.213.171.31]) by smtp.ultrahosting.com (Postfix) with ESMTP id E62CE82C7AC for ; Thu, 26 Feb 2009 12:44:57 -0500 (EST) Date: Thu, 26 Feb 2009 12:30:45 -0500 (EST) From: Christoph Lameter Subject: Re: [PATCH 20/20] Get rid of the concept of hot/cold page freeing In-Reply-To: <20090226171549.GH32756@csn.ul.ie> Message-ID: References: <1235344649-18265-21-git-send-email-mel@csn.ul.ie> <20090223013723.1d8f11c1.akpm@linux-foundation.org> <20090223233030.GA26562@csn.ul.ie> <20090223155313.abd41881.akpm@linux-foundation.org> <20090224115126.GB25151@csn.ul.ie> <20090224160103.df238662.akpm@linux-foundation.org> <20090225160124.GA31915@csn.ul.ie> <20090225081954.8776ba9b.akpm@linux-foundation.org> <20090226163751.GG32756@csn.ul.ie> <20090226171549.GH32756@csn.ul.ie> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org To: Mel Gorman Cc: Andrew Morton , linux-mm@kvack.org, penberg@cs.helsinki.fi, riel@redhat.com, kosaki.motohiro@jp.fujitsu.com, hannes@cmpxchg.org, npiggin@suse.de, linux-kernel@vger.kernel.org, ming.m.lin@intel.com, yanmin_zhang@linux.intel.com List-ID: On Thu, 26 Feb 2009, Mel Gorman wrote: > > I tried the general use of a pool of zeroed pages back in 2005. Zeroing > > made sense only if the code allocating the page did not immediately touch > > the cachelines of the page. > > Any feeling as to how often this was the case? Not often enough to justify the merging of my patches at the time. This was publicly discussed on lkml: http://lkml.indiana.edu/hypermail/linux/kernel/0503.2/0482.html > Indeed, any gain if it existed would be avoiding zeroing the pages used > by userspace. The cleanup would be reducing the amount of > architecture-specific code. > > I reckon it's worth an investigate but there is still other lower-lying > fruit. I hope we can get rid of various ugly elements of the quicklists if the page allocator would offer some sort of support. I would think that the slow allocation and freeing behavior is also a factor that makes quicklists advantageous. The quicklist page lists are simply a linked list of pages and a page can simply be dequeued and used. -- 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