From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx200.postini.com [74.125.245.200]) by kanga.kvack.org (Postfix) with SMTP id D130F6B004D for ; Tue, 26 Jun 2012 12:53:00 -0400 (EDT) Date: Tue, 26 Jun 2012 18:52:58 +0200 From: Andi Kleen Subject: Re: [PATCH 1/4] mm: introduce compaction and migration for virtio ballooned pages Message-ID: <20120626165258.GY11413@one.firstfloor.org> References: <7f83427b3894af7969c67acc0f27ab5aa68b4279.1340665087.git.aquini@redhat.com> <20120626101729.GF8103@csn.ul.ie> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20120626101729.GF8103@csn.ul.ie> Sender: owner-linux-mm@kvack.org List-ID: To: Mel Gorman Cc: Rafael Aquini , linux-mm@kvack.org, Rik van Riel , Andi Kleen , "Michael S. Tsirkin" , linux-kernel@vger.kernel.org, virtualization@lists.linux-foundation.org > > What shocked me actually is that VM_BUG_ON code is executed on > !CONFIG_DEBUG_VM builds and has been since 2.6.36 due to commit [4e60c86bd: > gcc-4.6: mm: fix unused but set warnings]. I thought the whole point of > VM_BUG_ON was to avoid expensive and usually unnecessary checks. Andi, > was this deliberate? The idea was that the compiler optimizes it away anyways. I'm not fully sure what putback_balloon_page does, but if it just tests a bit (without non variable test_bit) it should be ok. -Andi -- 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