From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx183.postini.com [74.125.245.183]) by kanga.kvack.org (Postfix) with SMTP id 89D906B004D for ; Mon, 14 May 2012 04:51:27 -0400 (EDT) Received: by pbbrp2 with SMTP id rp2so8382182pbb.14 for ; Mon, 14 May 2012 01:51:26 -0700 (PDT) Message-ID: <4FB0C789.6010107@gmail.com> Date: Mon, 14 May 2012 16:51:21 +0800 From: Cong Wang MIME-Version: 1.0 Subject: Re: [PATCH] mm: raise MemFree by reverting percpu_pagelist_fraction to 0 References: <4FACD00D.4060003@kernel.org> <4FACD573.4060103@kernel.org> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Sasha Levin Cc: Linus Torvalds , Minchan Kim , Hugh Dickins , Andrew Morton , linux-mm@kvack.org, linux-kernel@vger.kernel.org On 05/12/2012 12:35 AM, Sasha Levin wrote: > On Fri, May 11, 2012 at 6:27 PM, Linus Torvalds > wrote: >> On Fri, May 11, 2012 at 2:01 AM, Minchan Kim wrote: >>> >>> I didn't have a time so made quick patch to show just concept. >>> Not tested and Not consider carefully. >>> If anyone doesn't oppose, I will send formal patch which will have more beauty code. >> >> What's so magical about that '8' *anyway*? We do we have that minimum at all? >> >> At the very least, the 8-vs-0 thing needs to be explained. > > The '0' acts as an "off" switch. > > Once it's on, we reserve 1/x of the pages for the pagelists. I'm not > sure why 8 was selected in the first place, but I guess it made sense > that you don't want to reserve 15%+ of your memory for the pagelists. 1/x is not user-friendly, other vm sysctl's use percentage (x%), for example, overcommit_ratio. -- 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 internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org