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 37C986B011C for ; Mon, 20 Jun 2011 13:50:04 -0400 (EDT) Message-ID: <4DFF8848.2060802@redhat.com> Date: Mon, 20 Jun 2011 13:50:00 -0400 From: Rik van Riel MIME-Version: 1.0 Subject: Re: [PATCH 1/3] mm: completely disable THP by transparent_hugepage=never References: <1308587683-2555-1-git-send-email-amwang@redhat.com> <20110620165844.GA9396@suse.de> <4DFF7E3B.1040404@redhat.com> <4DFF7F0A.8090604@redhat.com> <4DFF8106.8090702@redhat.com> <4DFF8327.1090203@redhat.com> <4DFF84BB.3050209@redhat.com> In-Reply-To: <4DFF84BB.3050209@redhat.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Cong Wang Cc: Mel Gorman , linux-kernel@vger.kernel.org, akpm@linux-foundation.org, Andrea Arcangeli , Johannes Weiner , KAMEZAWA Hiroyuki , linux-mm@kvack.org On 06/20/2011 01:34 PM, Cong Wang wrote: > Even if it is really 10K, why not save it since it doesn't > much effort to make this. ;) Not only memory, but also time, > this could also save a little time to initialize the kernel. > > For me, the more serious thing is the logic, there is > no way to totally disable it as long as I have THP in .config > currently. This is why I said the design is broken. There are many things you cannot totally disable as long as they are enabled in the .config. Think about things like swap, or tmpfs - neither of which you are going to use in the crashdump kernel. I believe we need to keep the kernel optimized for common use and convenience. Crashdump is very much a corner case. Yes, using less memory in crashdump is worthwhile, but lets face it - the big memory user there is likely to be the struct page array, with everything else down in the noise... -- 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