From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail137.messagelabs.com (mail137.messagelabs.com [216.82.249.19]) by kanga.kvack.org (Postfix) with ESMTP id 6BEC790015D for ; Tue, 21 Jun 2011 23:24:22 -0400 (EDT) Received: from hpaq11.eem.corp.google.com (hpaq11.eem.corp.google.com [172.25.149.11]) by smtp-out.google.com with ESMTP id p5M3OJE5010725 for ; Tue, 21 Jun 2011 20:24:19 -0700 Received: from pwj1 (pwj1.prod.google.com [10.241.219.65]) by hpaq11.eem.corp.google.com with ESMTP id p5M3OGkD031943 (version=TLSv1/SSLv3 cipher=RC4-SHA bits=128 verify=NOT) for ; Tue, 21 Jun 2011 20:24:17 -0700 Received: by pwj1 with SMTP id 1so354746pwj.9 for ; Tue, 21 Jun 2011 20:24:15 -0700 (PDT) Date: Tue, 21 Jun 2011 20:24:14 -0700 (PDT) From: David Rientjes Subject: Re: [PATCH v2 1/4] mm: completely disable THP by transparent_hugepage=0 In-Reply-To: <4E015CB8.1010300@redhat.com> Message-ID: References: <1308643849-3325-1-git-send-email-amwang@redhat.com> <4E015CB8.1010300@redhat.com> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org List-ID: To: Cong Wang Cc: linux-kernel@vger.kernel.org, Andrew Morton , Randy Dunlap , Andrea Arcangeli , Rik van Riel , Johannes Weiner , KAMEZAWA Hiroyuki , linux-doc@vger.kernel.org, linux-mm@kvack.org On Wed, 22 Jun 2011, Cong Wang wrote: > > > Introduce "transparent_hugepage=0" to totally disable THP. > > > "transparent_hugepage=never" means setting THP to be partially > > > disabled, we need a new way to totally disable it. > > > > > > > Why can't you just compile it off so you never even compile > > mm/huge_memory.c in the first place and save the space in the kernel image > > as well? Having the interface available to enable the feature at runtime > > is worth the savings this patch provides, in my opinion. > > https://lkml.org/lkml/2011/6/20/506 > If you're proposing a patch for a specific purpose, it's appropriate to include that in the changelog. But now that I know what you're proposing this for, it's an easy NACK: transparent_hugepage=0 has no significant benefit over transparent_hugepage=never for kdump because the memory savings is negligible. -- 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