From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from westrelay02.boulder.ibm.com (westrelay02.boulder.ibm.com [9.17.195.11]) by e35.co.us.ibm.com (8.12.11/8.12.11) with ESMTP id k0QNWHf7006886 for ; Thu, 26 Jan 2006 18:32:17 -0500 Received: from d03av02.boulder.ibm.com (d03av02.boulder.ibm.com [9.17.195.168]) by westrelay02.boulder.ibm.com (8.12.10/NCO/VERS6.8) with ESMTP id k0QNUTeQ270224 for ; Thu, 26 Jan 2006 16:30:29 -0700 Received: from d03av02.boulder.ibm.com (loopback [127.0.0.1]) by d03av02.boulder.ibm.com (8.12.11/8.13.3) with ESMTP id k0QNWHqH032027 for ; Thu, 26 Jan 2006 16:32:17 -0700 Message-ID: <43D95BFE.4010705@us.ibm.com> Date: Thu, 26 Jan 2006 15:32:14 -0800 From: Matthew Dobson MIME-Version: 1.0 Subject: Re: [patch 0/9] Critical Mempools References: <1138217992.2092.0.camel@localhost.localdomain> <43D954D8.2050305@us.ibm.com> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: Christoph Lameter Cc: linux-kernel@vger.kernel.org, sri@us.ibm.com, andrea@suse.de, pavel@suse.cz, linux-mm@kvack.org List-ID: Christoph Lameter wrote: > On Thu, 26 Jan 2006, Matthew Dobson wrote: > > >>>All subsystems will now get more complicated by having to add this >>>emergency functionality? >> >>Certainly not. Only subsystems that want to use emergency pools will get >>more complicated. If you have a suggestion as to how to implement a >>similar feature that is completely transparent to its users, I would *love* > > > I thought the earlier __GFP_CRITICAL was a good idea. Well, I certainly could have used that feedback a month ago! ;) The general response to that patchset was overwhelmingly negative. Yours is the first vote in favor of that approach, that I'm aware of. >>to hear it. I have tried to keep the changes to implement this >>functionality to a minimum. As the patches currently stand, existing slab >>allocator and mempool users can continue using these subsystems without >>modification. > > > The patches are extensive and the required changes to subsystems in order > to use these pools are also extensive. I can't really argue with your first point, but the changes required to use the pools should actually be quite small. Sridhar (cc'd on this thread) is working on the changes required for the networking subsystem to use these pools, and it looks like the patches will be no larger than the ones from the last attempt. >>>There surely must be a better way than revising all subsystems for >>>critical allocations. >> >>Again, I could not find any way to implement this functionality without >>forcing the users of the functionality to make some, albeit very minor, >>changes. Specific suggestions are more than welcome! :) > > > Gfp flag? Better memory reclaim functionality? Well, I've got patches that implement the GFP flag approach, but as I mentioned above, that was poorly received. Better memory reclaim is a broad and general approach that I agree is useful, but will not necessarily solve the same set of problems (though it would likely lessen the severity somewhat). -Matt -- 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