Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261464AbVBWLnA (ORCPT ); Wed, 23 Feb 2005 06:43:00 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261465AbVBWLnA (ORCPT ); Wed, 23 Feb 2005 06:43:00 -0500 Received: from mx1.redhat.com ([66.187.233.31]:15827 "EHLO mx1.redhat.com") by vger.kernel.org with ESMTP id S261464AbVBWLm7 (ORCPT ); Wed, 23 Feb 2005 06:42:59 -0500 From: David Howells In-Reply-To: <20050222134010.4c286e64.akpm@osdl.org> References: <20050222134010.4c286e64.akpm@osdl.org> <20050222190646.GA7079@austin.ibm.com> <20050222115503.729cd17b.akpm@osdl.org> <20050222210752.GG22555@mail.shareable.org> To: Andrew Morton Cc: Jamie Lokier , olof@austin.ibm.com, linux-kernel@vger.kernel.org, torvalds@osdl.org, rusty@rustcorp.com.au Subject: Re: [PATCH/RFC] Futex mmap_sem deadlock X-Mailer: MH-E 7.82; nmh 1.0.4; GNU Emacs 21.3.50.1 Date: Wed, 23 Feb 2005 11:42:47 +0000 Message-ID: <5410.1109158967@redhat.com> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 657 Lines: 15 Andrew Morton wrote: > wrt this down_read/down_write/down_read deadlock: iirc, the reason why > down_write() takes precedence over down_read() is to avoid the permanent > writer starvation which would occur if there is heavy down_read() traffic. down_write() doesn't actually take precedence over down_read() as such. The rwsems try to implement a strict FIFO queue (the fairness thing). David - 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/