From mboxrd@z Thu Jan 1 00:00:00 1970 From: Matthew Wilcox Subject: Re: [PATCH v3] mm: make expand_downwards symmetrical to expand_upwards Date: Wed, 20 Apr 2011 13:25:41 -0600 Message-ID: <20110420192540.GC31296@parisc-linux.org> References: <20110420102314.4604.A69D9226@jp.fujitsu.com> <20110420161615.462D.A69D9226@jp.fujitsu.com> <20110420112020.GA31296@parisc-linux.org> <1303308938.2587.8.camel@mulgrave.site> <1303311779.2587.19.camel@mulgrave.site> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: James Bottomley , Pekka Enberg , KOSAKI Motohiro , Michal Hocko , Andrew Morton , Hugh Dickins , linux-mm@kvack.org, LKML , linux-parisc@vger.kernel.org, David Rientjes , Ingo Molnar , x86 maintainers , linux-arch@vger.kernel.org, Mel Gorman To: Christoph Lameter Return-path: In-Reply-To: List-ID: List-Id: linux-parisc.vger.kernel.org On Wed, Apr 20, 2011 at 10:22:04AM -0500, Christoph Lameter wrote: > There is barely any testing going on at all of this since we have had this > issue for more than 5 years and have not noticed it. The absence of bug > reports therefore proves nothing. Code inspection of the VM shows > that this is an issue that arises in multiple subsystems and that we have > VM_BUG_ONs in the page allocator that should trigger for these situations. So ... we've proven that people using these architectures use SLAB instead of SLUB, don't enable CONFIG_DEBUG_VM and don't use hugepages (not really a surprise ... nobody's running Oracle on these arches :-) I don't think that qualifies as "barely any testing". I think that's "nobody developing the Linux MM uses one of these architectures". -- Matthew Wilcox Intel Open Source Technology Centre "Bill, look, we understand that you're interested in selling us this operating system, but compare it to ours. We can't possibly take such a retrograde step."