From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <45BEA73C.5030809@yahoo.com.au> Date: Tue, 30 Jan 2007 13:02:36 +1100 From: Nick Piggin MIME-Version: 1.0 Subject: Re: [PATCH] mm: remove global locks from mm/highmem.c References: <1169993494.10987.23.camel@lappy> <20070128142925.df2f4dce.akpm@osdl.org> <20070129190806.GA14353@elte.hu> In-Reply-To: <20070129190806.GA14353@elte.hu> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: Ingo Molnar Cc: Andrew Morton , Peter Zijlstra , linux-kernel@vger.kernel.org, linux-mm@kvack.org List-ID: Ingo Molnar wrote: > For every 64-bit Fedora box there's more than seven 32-bit boxes. I > think 32-bit is going to live with us far longer than many thought, so > we might as well make it work better. Both HIGHMEM and HIGHPTE is the > default on many distro kernels, which pushes the kmap infrastructure > quite a bit. I don't think anybody would argue against numbers, but just that there are not many big 32-bit SMPs anymore. And if Bill Irwin didn't fix the kmap problem back then, it would be interesting to see a system and workload where it actually is a bottleneck. Not that I'm against any patch to improve scalability, if it doesn't hurt single-threaded performance ;) > the problem is that everything that was easy to migrate was migrated off > kmap() already - and it's exactly those hard cases that cannot be > converted (like the pagecache use) which is the most frequent kmap() > users. Which pagecache use? file_read_actor()? -- 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