From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Mon, 12 Dec 2005 05:51:46 +0100 From: Andi Kleen Subject: Re: [RFC 1/6] Framework Message-ID: <20051212045146.GA11190@wotan.suse.de> References: <20051210005440.3887.34478.sendpatchset@schroedinger.engr.sgi.com> <20051210005445.3887.94119.sendpatchset@schroedinger.engr.sgi.com> <439CF2A2.60105@yahoo.com.au> <20051212035631.GX11190@wotan.suse.de> <439CF93D.5090207@yahoo.com.au> <20051212042142.GZ11190@wotan.suse.de> <439CFC67.4030107@yahoo.com.au> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <439CFC67.4030107@yahoo.com.au> Sender: owner-linux-mm@kvack.org Return-Path: To: Nick Piggin Cc: Andi Kleen , Christoph Lameter , linux-kernel@vger.kernel.org, Hugh Dickins , linux-mm@kvack.org, Marcelo Tosatti List-ID: > >With local_t you don't need to turn off interrupts > >anymore. > > > > Then you can't use __local_xxx, and so many architectures will use > atomic instructions (the ones who don't are the ones with tripled > cacheline footprint of this structure). They are wrong then. atomic instructions is the wrong implementation and they would be better off with asm-generic. If anything they should use per_cpu counters for interrupts and use seq locks. Or just turn off the interrupts for a short time in the low level code. > > Sure i386 and x86-64 are happy, but this would probably slow down > most other architectures. I think it is better to fix the other architectures then - if they are really using a full scale bus lock for this they're just wrong. I don't think it is a good idea to do a large change in generic code just for dumb low level code. -Andi -- 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