From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pa0-f41.google.com (mail-pa0-f41.google.com [209.85.220.41]) by kanga.kvack.org (Postfix) with ESMTP id 11B496B0125 for ; Thu, 8 May 2014 18:34:37 -0400 (EDT) Received: by mail-pa0-f41.google.com with SMTP id lj1so3408899pab.14 for ; Thu, 08 May 2014 15:34:36 -0700 (PDT) Received: from mail.linuxfoundation.org (mail.linuxfoundation.org. [140.211.169.12]) by mx.google.com with ESMTP id yd10si1168358pab.2.2014.05.08.15.34.35 for ; Thu, 08 May 2014 15:34:36 -0700 (PDT) Date: Thu, 8 May 2014 15:34:33 -0700 From: Andrew Morton Subject: Re: [PATCH 2/2] mm/page_alloc: DEBUG_VM checks for free_list placement of CMA and RESERVE pages Message-Id: <20140508153433.7fcbe624549259b68659fe10@linux-foundation.org> In-Reply-To: <20140508061937.GE5282@bbox> References: <533D8015.1000106@suse.cz> <1396539618-31362-1-git-send-email-vbabka@suse.cz> <1396539618-31362-2-git-send-email-vbabka@suse.cz> <53616F39.2070001@oracle.com> <53638ADA.5040200@suse.cz> <5367A1E5.2020903@oracle.com> <5367B356.1030403@suse.cz> <20140507013333.GB26212@bbox> <536A4A3B.1090403@suse.cz> <20140508055421.GC9161@js1304-P5Q-DELUXE> <20140508061937.GE5282@bbox> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Minchan Kim Cc: Joonsoo Kim , Vlastimil Babka , Sasha Levin , Bartlomiej Zolnierkiewicz , linux-kernel@vger.kernel.org, linux-mm@kvack.org, Mel Gorman , Yong-Taek Lee , KOSAKI Motohiro , Marek Szyprowski , Hugh Dickins , Rik van Riel , Michal Nazarewicz , Dave Jones On Thu, 8 May 2014 15:19:37 +0900 Minchan Kim wrote: > > I also think that VM_DEBUG overhead isn't problem because of same > > reason from Vlastimil. > > Guys, please read this. > > https://lkml.org/lkml/2013/7/17/591 > > If you guys really want it, we could separate it with > CONFIG_DEBUG_CMA or CONFIG_DEBUG_RESERVE like stuff. > Otherwise, just remain in mmotm. Wise words, those. Yes, these checks are in a pretty hot path. I'm inclined to make the patch -mm (and -next) only. Unless there's a really good reason, such as "nobody who uses CMA is likely to be testing -next", which sounds likely :( -- 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