From mboxrd@z Thu Jan 1 00:00:00 1970 From: Benjamin Herrenschmidt Subject: Re: [announce 7/7] fbsplash - documentation Date: Fri, 11 Mar 2005 23:27:47 +1100 Message-ID: <1110544067.5810.100.camel@gaston> References: <20050308021706.GH26249@spock.one.pl> <200503080418.08804.arnd@arndb.de> <20050308223728.GA11065@spock.one.pl> <200503090117.12755.arnd@arndb.de> Reply-To: linux-fbdev-devel@lists.sourceforge.net Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Received: from sc8-sf-mx2-b.sourceforge.net ([10.3.1.12] helo=sc8-sf-mx2.sourceforge.net) by sc8-sf-list1.sourceforge.net with esmtp (Exim 4.30) id 1D9jFS-0001PG-Sd for linux-fbdev-devel@lists.sourceforge.net; Fri, 11 Mar 2005 04:28:10 -0800 Received: from gate.crashing.org ([63.228.1.57]) by sc8-sf-mx2.sourceforge.net with esmtp (TLSv1:AES256-SHA:256) (Exim 4.41) id 1D9jFR-0005y2-CY for linux-fbdev-devel@lists.sourceforge.net; Fri, 11 Mar 2005 04:28:10 -0800 In-Reply-To: <200503090117.12755.arnd@arndb.de> Sender: linux-fbdev-devel-admin@lists.sourceforge.net Errors-To: linux-fbdev-devel-admin@lists.sourceforge.net List-Unsubscribe: , List-Id: List-Post: List-Help: List-Subscribe: , List-Archive: Content-Type: text/plain; charset="us-ascii" To: Arnd Bergmann Cc: Michal Januszewski , Linux Kernel list , Linux Fbdev development list > > I don't understand. Does the kernel code need to wait for the helper > to finish while holding the semaphore? AFAICS, the helper is completely > asynchronous, so it can simply do its job when the kernel has given > up the semaphore. It should be totally async witout any sem. there is no guarantee that userspace is even available at the time you do the call. ------------------------------------------------------- SF email is sponsored by - The IT Product Guide Read honest & candid reviews on hundreds of IT Products from real users. Discover which products truly live up to the hype. Start reading now. http://ads.osdn.com/?ad_id=6595&alloc_id=14396&op=click From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262698AbVCKMaR (ORCPT ); Fri, 11 Mar 2005 07:30:17 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262703AbVCKM2U (ORCPT ); Fri, 11 Mar 2005 07:28:20 -0500 Received: from gate.crashing.org ([63.228.1.57]:7389 "EHLO gate.crashing.org") by vger.kernel.org with ESMTP id S262702AbVCKM2L (ORCPT ); Fri, 11 Mar 2005 07:28:11 -0500 Subject: Re: [announce 7/7] fbsplash - documentation From: Benjamin Herrenschmidt To: Arnd Bergmann Cc: Michal Januszewski , Linux Kernel list , Linux Fbdev development list In-Reply-To: <200503090117.12755.arnd@arndb.de> References: <20050308021706.GH26249@spock.one.pl> <200503080418.08804.arnd@arndb.de> <20050308223728.GA11065@spock.one.pl> <200503090117.12755.arnd@arndb.de> Content-Type: text/plain Date: Fri, 11 Mar 2005 23:27:47 +1100 Message-Id: <1110544067.5810.100.camel@gaston> Mime-Version: 1.0 X-Mailer: Evolution 2.0.3 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org > > I don't understand. Does the kernel code need to wait for the helper > to finish while holding the semaphore? AFAICS, the helper is completely > asynchronous, so it can simply do its job when the kernel has given > up the semaphore. It should be totally async witout any sem. there is no guarantee that userspace is even available at the time you do the call.