From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mail-bw0-f46.google.com ([209.85.214.46]:36355 "EHLO mail-bw0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752047Ab0FFMjl (ORCPT ); Sun, 6 Jun 2010 08:39:41 -0400 Date: Sun, 6 Jun 2010 14:43:02 +0200 From: Richard Zidlicky To: Jiri Slaby Cc: linux-kernel@vger.kernel.org, linux-media@vger.kernel.org Subject: [PATCH 2.6.34] schedule inside spin_lock_irqsave Message-ID: <20100606124302.GA10119@linux-m68k.org> References: <20100530145240.GA21559@linux-m68k.org> <4C028336.8030704@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4C028336.8030704@gmail.com> Sender: linux-media-owner@vger.kernel.org List-ID: 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); - - /* 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())); return cb; } Richard