From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Wed, 7 Jun 2006 17:25:33 +0100 (IST) From: Mel Gorman Subject: Re: [PATCH 0/5] Sizing zones and holes in an architecture independent manner V7 In-Reply-To: <200606071720.22242.ak@suse.de> Message-ID: References: <20060606134710.21419.48239.sendpatchset@skynet.skynet.ie> <200606071216.24640.ak@suse.de> <200606071720.22242.ak@suse.de> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed Sender: owner-linux-mm@kvack.org Return-Path: To: Andi Kleen Cc: Andrew Morton , davej@codemonkey.org.uk, tony.luck@intel.com, bob.picco@hp.com, linux-kernel@vger.kernel.org, linuxppc-dev@ozlabs.org, linux-mm@kvack.org List-ID: On Wed, 7 Jun 2006, Andi Kleen wrote: > >> Ok, while true, I'm not sure how it affects performance. The only "real" >> value affected by present_pages is the number of patches that are >> allocated in batches to the per-cpu allocator. > > It affects the low/high water marks in the VM zone balancer. > ok, that's true. The watermarks would be higher if memmap and the kernel image is not taken into account. Arguably, the same applies to bootmem allocations. This hits all architectures *except* x86_64. > Especially for the 16MB DMA zone it can make a difference if you > account 4MB kernel in there or not. > I'm guessing it's a difficult-to-trigger problem or it would have been reported for other arches. Assuming it can be triggered and that is what was causing your problems, it's still worth fixing in the arch-independent code rather than burying it in arch/somewhere, right? -- Mel Gorman Part-time Phd Student Linux Technology Center University of Limerick IBM Dublin Software Lab -- 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