Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757610AbWKXLDA (ORCPT ); Fri, 24 Nov 2006 06:03:00 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1757620AbWKXLDA (ORCPT ); Fri, 24 Nov 2006 06:03:00 -0500 Received: from zeus1.kernel.org ([204.152.191.4]:1201 "EHLO zeus1.kernel.org") by vger.kernel.org with ESMTP id S1757608AbWKXLC4 (ORCPT ); Fri, 24 Nov 2006 06:02:56 -0500 Date: Fri, 24 Nov 2006 14:01:44 +0300 From: Evgeniy Polyakov To: Ulrich Drepper Cc: David Miller , Andrew Morton , netdev , Zach Brown , Christoph Hellwig , Chase Venters , Johann Borck , linux-kernel@vger.kernel.org, Jeff Garzik Subject: Re: [take25 1/6] kevent: Description. Message-ID: <20061124110143.GF13600@2ka.mipt.ru> References: <11641265982190@2ka.mipt.ru> <4564E162.8040901@redhat.com> <20061123115240.GA20294@2ka.mipt.ru> <4565FA60.9000402@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <4565FA60.9000402@redhat.com> User-Agent: Mutt/1.5.9i X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-1.7.5 (2ka.mipt.ru [0.0.0.0]); Fri, 24 Nov 2006 14:01:46 +0300 (MSK) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1331 Lines: 30 On Thu, Nov 23, 2006 at 11:45:36AM -0800, Ulrich Drepper (drepper@redhat.com) wrote: > Evgeniy Polyakov wrote: > >Kernel does not put there a new entry, it is only done inside > >kevent_wait(). Entries are put into queue (in any context), where they can > >be obtained > >from only kevent_wait() or kevent_get_events(). > > I know this is how it's done now. But it is not where it has to end. > IMO we have to get to a solution where new events are posted to the ring > buffer asynchronously, i.e., without a thread calling kevent_wait. And > then you need the extra parameter and verification. Even if it's today > not needed we have to future-proof the interface since it cannot be > changed once in use. There is a special flag in kevent_user to wake it if there are no ready events - kernel thread which has added new events will set it and thus subsequent kevent_wait() will return with updated indexes - userspace must check indexes after kevent_wait(). > -- > ➧ Ulrich Drepper ➧ Red Hat, Inc. ➧ 444 Castro St ➧ Mountain View, > CA ❖ -- Evgeniy Polyakov - 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/