Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261677AbVASJW3 (ORCPT ); Wed, 19 Jan 2005 04:22:29 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261674AbVASJWK (ORCPT ); Wed, 19 Jan 2005 04:22:10 -0500 Received: from mx2.elte.hu ([157.181.151.9]:50865 "EHLO mx2.elte.hu") by vger.kernel.org with ESMTP id S261663AbVASJUX (ORCPT ); Wed, 19 Jan 2005 04:20:23 -0500 Date: Wed, 19 Jan 2005 10:20:13 +0100 From: Ingo Molnar To: Peter Chubb Cc: Tony Luck , Darren Williams , Andrew Morton , Chris Wedgwood , torvalds@osdl.org, benh@kernel.crashing.org, linux-kernel@vger.kernel.org, Ia64 Linux , Christoph Hellwig Subject: Re: Horrible regression with -CURRENT from "Don't busy-lock-loop in preemptable spinlocks" patch Message-ID: <20050119092013.GA2045@elte.hu> References: <20050117055044.GA3514@taniwha.stupidest.org> <20050116230922.7274f9a2.akpm@osdl.org> <20050117143301.GA10341@elte.hu> <20050118014752.GA14709@cse.unsw.EDU.AU> <16877.42598.336096.561224@wombat.chubb.wattle.id.au> <20050119080403.GB29037@elte.hu> <16878.9678.73202.771962@wombat.chubb.wattle.id.au> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <16878.9678.73202.771962@wombat.chubb.wattle.id.au> User-Agent: Mutt/1.4.1i X-ELTE-SpamVersion: MailScanner 4.31.6-itk1 (ELTE 1.2) SpamAssassin 2.63 ClamAV 0.73 X-ELTE-VirusStatus: clean X-ELTE-SpamCheck: no X-ELTE-SpamCheck-Details: score=-4.9, required 5.9, autolearn=not spam, BAYES_00 -4.90 X-ELTE-SpamLevel: X-ELTE-SpamScore: -4 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 874 Lines: 24 * Peter Chubb wrote: > >> Here's a patch that adds the missing read_is_locked() and > >> write_is_locked() macros for IA64. When combined with Ingo's > >> patch, I can boot an SMP kernel with CONFIG_PREEMPT on. > >> > >> However, I feel these macros are misnamed: read_is_locked() returns > >> true if the lock is held for writing; write_is_locked() returns > >> true if the lock is held for reading or writing. > > Ingo> well, 'read_is_locked()' means: "will a read_lock() succeed" > > Fail, surely? yeah ... and with that i proved beyond doubt that the naming is indeed unintuitive :-) Ingo - 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/