Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754083Ab0FGM5w (ORCPT ); Mon, 7 Jun 2010 08:57:52 -0400 Received: from mail-ww0-f46.google.com ([74.125.82.46]:50615 "EHLO mail-ww0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752006Ab0FGM5u (ORCPT ); Mon, 7 Jun 2010 08:57:50 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=googlemail.com; s=gamma; h=sender:date:from:to:cc:subject:message-id:references:mime-version :content-type:content-disposition:in-reply-to:user-agent; b=i/it+O45Jgp2AcizCsr9ZXnyJr3f55elP0zhtSk5QcGaLsPCd01peilBV55Ziz3TB2 ZpRXlZ5JQZ0hVkNgPr0pi9MC15tbhVz5gsBjwi2jYihddoceeP4L/gtL2y0QyLg4a1zo FAazsNj8tzxxyJUx0FmT27MdXbU3HpdIX7Usc= Date: Mon, 7 Jun 2010 15:00:48 +0200 From: Richard Zidlicky To: Jiri Slaby Cc: linux-kernel@vger.kernel.org, linux-media@vger.kernel.org Subject: Re: [PATCH 2.6.34] schedule inside spin_lock_irqsave Message-ID: <20100607130048.GA6857@linux-m68k.org> References: <20100530145240.GA21559@linux-m68k.org> <4C028336.8030704@gmail.com> <20100606124302.GA10119@linux-m68k.org> <4C0BE03C.8000709@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4C0BE03C.8000709@gmail.com> User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3049 Lines: 92 On Sun, Jun 06, 2010 at 07:51:56PM +0200, Jiri Slaby wrote: > On 06/06/2010 02:43 PM, Richard Zidlicky wrote: > > Hi, > > > > I have done a minimaly invasive patch for the stable 2.6.34 kernel and stress-tested > > it for many hours, definitely seems to improve the behaviour. > > > > I have left out your beautification suggestion for now, want to do more playing with > > other aspects of the driver. There still seem to be issues when the device is unplugged > > while in use and such. > > > > --- linux-2.6.34/drivers/media/dvb/siano/smscoreapi.c.rz 2010-06-03 21:58:11.000000000 +0200 > > +++ linux-2.6.34/drivers/media/dvb/siano/smscoreapi.c 2010-06-04 23:00:35.000000000 +0200 > > @@ -1100,31 +1100,26 @@ > > * > > * @return pointer to descriptor on success, NULL on error. > > */ > > -struct smscore_buffer_t *smscore_getbuffer(struct smscore_device_t *coredev) > > + > > +struct smscore_buffer_t *get_entry(void) > > { > > struct smscore_buffer_t *cb = NULL; > > unsigned long flags; > > > > - DEFINE_WAIT(wait); > > - > > spin_lock_irqsave(&coredev->bufferslock, flags); > > Sorry, maybe I'm just blind, but where is 'coredev' defined in this > scope? You probably forgot to pass it to get_entry? > > How could this be compiled? Is there coredev defined globally? good catch. I think it failed and despite a different kernel id the old module was loaded. Here is the new version, this time lightly tested --- linux-2.6.34/drivers/media/dvb/siano/smscoreapi.c.rz 2010-06-03 21:58:11.000000000 +0200 +++ linux-2.6.34/drivers/media/dvb/siano/smscoreapi.c 2010-06-07 14:32:06.000000000 +0200 @@ -1100,31 +1100,26 @@ * * @return pointer to descriptor on success, NULL on error. */ -struct smscore_buffer_t *smscore_getbuffer(struct smscore_device_t *coredev) + +struct smscore_buffer_t *get_entry(struct smscore_device_t *coredev) { struct smscore_buffer_t *cb = NULL; unsigned long flags; - DEFINE_WAIT(wait); - spin_lock_irqsave(&coredev->bufferslock, flags); - - /* This function must return a valid buffer, since the buffer list is - * finite, we check that there is an available buffer, if not, we wait - * until such buffer become available. - */ - - prepare_to_wait(&coredev->buffer_mng_waitq, &wait, TASK_INTERRUPTIBLE); - - if (list_empty(&coredev->buffers)) - schedule(); - - finish_wait(&coredev->buffer_mng_waitq, &wait); - + if (!list_empty(&coredev->buffers)) { cb = (struct smscore_buffer_t *) coredev->buffers.next; list_del(&cb->entry); - + } spin_unlock_irqrestore(&coredev->bufferslock, flags); + return cb; +} + +struct smscore_buffer_t *smscore_getbuffer(struct smscore_device_t *coredev) +{ + struct smscore_buffer_t *cb = NULL; + + wait_event(coredev->buffer_mng_waitq, (cb = get_entry(coredev))); return cb; } Richard -- 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/