From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <436BF7D3.1090200@yahoo.com.au> Date: Sat, 05 Nov 2005 11:07:47 +1100 From: Nick Piggin MIME-Version: 1.0 Subject: Re: [Lhms-devel] [PATCH 0/7] Fragmentation Avoidance V19 References: <20051104201248.GA14201@elte.hu> <20051104210418.BC56F184739@thermo.lanl.gov> <200511042343.27832.ak@suse.de> In-Reply-To: <200511042343.27832.ak@suse.de> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: Andi Kleen Cc: Gregory Maxwell , Andy Nelson , mingo@elte.hu, akpm@osdl.org, arjan@infradead.org, arjanv@infradead.org, haveblue@us.ibm.com, kravetz@us.ibm.com, lhms-devel@lists.sourceforge.net, linux-kernel@vger.kernel.org, linux-mm@kvack.org, mbligh@mbligh.org, mel@csn.ul.ie, torvalds@osdl.org List-ID: Andi Kleen wrote: > On Friday 04 November 2005 22:31, Gregory Maxwell wrote: > >> >>Thats the idea. The 'hugetlb zone' will only be usable for allocations >>which are guaranteed reclaimable. Reclaimable includes userspace >>usage (since at worst an in use userspace page can be swapped out then >>paged back into another physical location). > > > I don't like it very much. You have two choices if a workload runs > out of the kernel allocatable pages. Either you spill into the reclaimable > zone or you fail the allocation. The first means that the huge pages > thing is unreliable, the second would mean that all the many problems > of limited lowmem would be back. > These are essentially the same problems that the frag patches face as well. > None of this is very attractive. > Though it is simple and I expect it should actually do a really good job for the non-kernel-intensive HPC group, and the highly tuned database group. Nick -- SUSE Labs, Novell Inc. Send instant messages to your online friends http://au.messenger.yahoo.com -- 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