Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261297AbVEAW4R (ORCPT ); Sun, 1 May 2005 18:56:17 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261308AbVEAW4R (ORCPT ); Sun, 1 May 2005 18:56:17 -0400 Received: from fire.osdl.org ([65.172.181.4]:38095 "EHLO smtp.osdl.org") by vger.kernel.org with ESMTP id S261297AbVEAW4M (ORCPT ); Sun, 1 May 2005 18:56:12 -0400 Date: Sun, 1 May 2005 15:55:35 -0700 From: Andrew Morton To: Nish Aravamudan Cc: stern@rowland.harvard.edu, arvidjaar@mail.ru, linux-usb-devel@lists.sourceforge.net, linux-kernel@vger.kernel.org Subject: Re: [linux-usb-devel] init 1 kill khubd on 2.6.11 Message-Id: <20050501155535.3855d31f.akpm@osdl.org> In-Reply-To: <29495f1d050501154625ee7087@mail.gmail.com> References: <200505012021.56649.arvidjaar@mail.ru> <20050501153051.2471294e.akpm@osdl.org> <29495f1d050501154625ee7087@mail.gmail.com> X-Mailer: Sylpheed version 1.0.0 (GTK+ 1.2.10; i386-vine-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1808 Lines: 44 Nish Aravamudan wrote: > > > - /* Send me a signal to get me die (for debugging) */ > > do { > > hub_events(); > > - wait_event_interruptible(khubd_wait, !list_empty(&hub_event_list)); > > + wait_event_interruptible(khubd_wait, > > + !list_empty(&hub_event_list) || > > + kthread_should_stop()); > > try_to_freeze(PF_FREEZE); > > - } while (!signal_pending(current)); > > + } while (!kthread_should_stop() || !list_empty(&hub_event_list)); > > Shouldn't this simply be a wait_event(), instead of > wait_event_interruptible()? That would cause uninterruptible sleep, which contributes to load average. > Then the do-while() can be gotten rid of, > as the only reason it is there currently, I guess, is to ignore > signals? Nope, the do-while is a basic part of the daemon's operation: keep doing stuff until either there's no stuff to do or until we're told to exit. > Also, the while's conditional should be (!kthread_should_stop() || > list_empty(&hub_event_list) to match the negation of wait_event's? > (wait_event() expects the condition to stop on, while while() expects > the condition to continue on) Nope, the wait_event_interruptible test says "sleep unless the list is not empty or I am being asked to exit" the while termination test says "loop until the list is empty and I am being asked to stop". I think. I had to scratch my head for a while over that code ;) - 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/