Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Fri, 7 Dec 2001 16:37:53 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Fri, 7 Dec 2001 16:37:41 -0500 Received: from eventhorizon.antefacto.net ([193.120.245.3]:30343 "EHLO eventhorizon.antefacto.net") by vger.kernel.org with ESMTP id ; Fri, 7 Dec 2001 16:37:24 -0500 Message-ID: <3C11368F.4020408@antefacto.com> Date: Fri, 07 Dec 2001 21:37:19 +0000 From: Padraig Brady User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:0.9.6) Gecko/20011120 X-Accept-Language: en-us MIME-Version: 1.0 To: Michael Poole CC: linux-kernel@vger.kernel.org Subject: Re: horrible disk thorughput on itanium In-Reply-To:

<20011207185847.A20876@wotan.suse.de> <87wuzyq4ms.fsf@sanosuke.troilus.org> <3C110C0B.4030102@antefacto.com> <87snampvww.fsf@sanosuke.troilus.org> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Michael Poole wrote: > Padraig Brady writes: > > >>This breaks for the case discussed @ >>http://sources.redhat.com/ml/bug-glibc/2001-11/msg00079.html >>I.E. if you have a multithreaded lib being linked by >>single threaded apps (Note multithreaded lib, not just a >>threadsafe lib (I.E. the lib calls pthread_create())). >> > > That's an interesting, but very contrived, example. Can you find a > single multi-threaded lib that uses FILE*'s shared with the > application using it? Well you have to deal with the general case. A single threaded app linking against a multithreaded lib. It mightn't be just shared FILE*'s that could cause problems. > Linus's suggestion to add hooks to pthread_create() gets around that > problem, anyway. I don't think this will work as I said before current apps that use _unlocked() functions directly manipulate the stdio structures, hence a "new smarter locking stdio" would never get used by existing compiled apps. > Alternatively, the multi-threaded library could > require any application linking to it to define _REENTRANT. It could, but what if an existing interface (lib) is changed from signle to multithreaded. You can't preclude this. > After all, it's silly to talk about a 'multi-threaded' library linked > to a 'single-threaded' application -- the application plus any > libraries, as a whole, are either multithreaded or not. They have to > be on the same page to deal with *any* locking issues. > > -- Michael Padraig. - 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/