From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Wed, 8 Aug 2007 11:09:06 -0700 (PDT) From: Christoph Lameter Subject: Re: [PATCH 02/10] mm: system wide ALLOC_NO_WATERMARK In-Reply-To: <4a5909270708080037n32be2a73k5c28d33bb02f770b@mail.gmail.com> Message-ID: References: <20070806102922.907530000@chello.nl> <200708061559.41680.phillips@phunq.net> <200708061649.56487.phillips@phunq.net> <4a5909270708080037n32be2a73k5c28d33bb02f770b@mail.gmail.com> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org Return-Path: To: Daniel Phillips Cc: Daniel Phillips , Peter Zijlstra , Matt Mackall , linux-kernel@vger.kernel.org, linux-mm@kvack.org, David Miller , Andrew Morton , Daniel Phillips List-ID: On Wed, 8 Aug 2007, Daniel Phillips wrote: > 1. If the allocation can be satisified in the usual way, do that. > 2. Otherwise, if the GFP flags do not include __GFP_MEMALLOC or > PF_MEMALLOC is not set, fail the allocation > 3. Otherwise, if the memcache's reserve quota is not reached, > satisfy the request, allocating a new page from the MEMALLOC reserve, > but the memcache's reserve counter and succeed Maybe we need to kill PF_MEMALLOC.... > > Try NUMA constraints and zone limitations. > > Are you worried about a correctness issue that would prevent the > machine from operating, or are you just worried about allocating > reserve pages to the local node for performance reasons? I am worried that allocation constraints will make the approach incorrect. Because logically you must have distinct pools for each set of allocations constraints. Otherwise something will drain the precious reserve slab. > > No I mean all 1024 processors of our system running into this fail/succeed > > thingy that was added. > > If an allocation now fails that would have succeeded in the past, the > patch set is buggy. I can't say for sure one way or another at this > time of night. If you see something, could you please mention a > file/line number? It seems that allocations fail that the reclaim logic should have taken care of letting succeed. Not good. -- 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