Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Sat, 23 Feb 2002 16:10:48 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Sat, 23 Feb 2002 16:10:36 -0500 Received: from lightning.swansea.linux.org.uk ([194.168.151.1]:4112 "EHLO the-village.bc.nu") by vger.kernel.org with ESMTP id ; Sat, 23 Feb 2002 16:10:24 -0500 Subject: Re: [PATCH] Lightweight userspace semaphores... To: lm@bitmover.com (Larry McVoy) Date: Sat, 23 Feb 2002 21:22:59 +0000 (GMT) Cc: torvalds@transmeta.com (Linus Torvalds), mingo@elte.hu (Ingo Molnar), rusty@rustcorp.com.au (Rusty Russell), matthew@hairy.beasts.org (Matthew Kirkwood), bcrl@redhat.com (Benjamin LaHaise), david@mysql.com (David Axmark), wli@holomorphy.com (William Lee Irwin III), linux-kernel@vger.kernel.org In-Reply-To: <20020223102805.F11156@work.bitmover.com> from "Larry McVoy" at Feb 23, 2002 10:28:05 AM X-Mailer: ELM [version 2.5 PL6] MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Message-Id: From: Alan Cox Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org > Exactly. SMP gives you coherent memory and test-and-set or some other > atomic operation. Why not use it? Coherent memory on some platforms, locks on some platforms. Fortunately both on several important architectures. It needs a much cleaner API but in user space to wrap the user mode/kernel mode mixed locks. You need the kernel side for sleeping cases - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/