From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_2 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id DCE47C55189 for ; Wed, 22 Apr 2020 12:53:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B5DCC20857 for ; Wed, 22 Apr 2020 12:53:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727040AbgDVMxs (ORCPT ); Wed, 22 Apr 2020 08:53:48 -0400 Received: from mail.kernel.org ([198.145.29.99]:33196 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725924AbgDVMxs (ORCPT ); Wed, 22 Apr 2020 08:53:48 -0400 Received: from gandalf.local.home (cpe-66-24-58-225.stny.res.rr.com [66.24.58.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 4E87720776; Wed, 22 Apr 2020 12:53:47 +0000 (UTC) Date: Wed, 22 Apr 2020 08:53:45 -0400 From: Steven Rostedt To: Peter Zijlstra Cc: mingo@kernel.org, linux-kernel@vger.kernel.org, tglx@linutronix.de, qais.yousef@arm.com, juri.lelli@redhat.com, vincent.guittot@linaro.org, dietmar.eggemann@arm.com, bsegall@google.com, mgorman@suse.de, hverkuil@xs4all.nl, awalls@md.metrocast.net Subject: Re: [PATCH 09/23] sched,ivtv: Convert to sched_set_fifo*() Message-ID: <20200422085345.48b50508@gandalf.local.home> In-Reply-To: <20200422112831.752048390@infradead.org> References: <20200422112719.826676174@infradead.org> <20200422112831.752048390@infradead.org> X-Mailer: Claws Mail 3.17.3 (GTK+ 2.24.32; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 22 Apr 2020 13:27:28 +0200 Peter Zijlstra wrote: > Because SCHED_FIFO is a broken scheduler model (see previous patches) > take away the priority field, the kernel can't possibly make an > informed decision. > > Effectively changes from 99 to 50. I wonder for the 99 users, we should have a sched_set_high() that would set the task to something like 75. That is, above default 50? -- Steve > > Cc: hverkuil@xs4all.nl > Cc: awalls@md.metrocast.net > Signed-off-by: Peter Zijlstra (Intel) > Reviewed-by: Ingo Molnar > --- > drivers/media/pci/ivtv/ivtv-driver.c | 4 +--- > 1 file changed, 1 insertion(+), 3 deletions(-) > > --- a/drivers/media/pci/ivtv/ivtv-driver.c > +++ b/drivers/media/pci/ivtv/ivtv-driver.c > @@ -737,8 +737,6 @@ static void ivtv_process_options(struct > */ > static int ivtv_init_struct1(struct ivtv *itv) > { > - struct sched_param param = { .sched_priority = 99 }; > - > itv->base_addr = pci_resource_start(itv->pdev, 0); > itv->enc_mbox.max_mbox = 2; /* the encoder has 3 mailboxes (0-2) */ > itv->dec_mbox.max_mbox = 1; /* the decoder has 2 mailboxes (0-1) */ > @@ -758,7 +756,7 @@ static int ivtv_init_struct1(struct ivtv > return -1; > } > /* must use the FIFO scheduler as it is realtime sensitive */ > - sched_setscheduler(itv->irq_worker_task, SCHED_FIFO, ¶m); > + sched_set_fifo(itv->irq_worker_task); > > kthread_init_work(&itv->irq_work, ivtv_irq_work_handler); > >