From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Fri, 3 Nov 2006 14:15:53 -0800 (PST) From: Christoph Lameter Subject: Re: Page allocator: Single Zone optimizations In-Reply-To: <20061103141218.8dbdbd14.akpm@osdl.org> Message-ID: References: <20061101123451.3fd6cfa4.akpm@osdl.org> <454A2CE5.6080003@shadowen.org> <20061103135013.6bdc6240.akpm@osdl.org> <20061103141218.8dbdbd14.akpm@osdl.org> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org Return-Path: To: Andrew Morton Cc: Mel Gorman , Andy Whitcroft , Nick Piggin , KAMEZAWA Hiroyuki , Linux Memory Management List , Peter Zijlstra List-ID: On Fri, 3 Nov 2006, Andrew Morton wrote: > That's possibly useful if the cache has a destructor. If it has a > constructor and no destructor then there's no point in locally caching the > pages. > > But destructors are a bad idea: you dirty a cacheline, evict something else > and then let the cacheline just sit there and go stale. Right thats why I tried to avoid constructors and destructors for the new slab design but it is important for RCU since the object must be in a defined state even after a free. i386 arch code does some weird wizardry with it. So I had to add a support layer. > But I thought that slab once-upon-a-time retained caches of plain old free > pages, not in any particular state. Maybe it did and maybe we did remove > that. Must have been before my time. -- 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