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=-5.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,UNPARSEABLE_RELAY, URIBL_BLOCKED,USER_AGENT_SANE_1 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 9817EC19759 for ; Thu, 1 Aug 2019 11:27:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 700CD2171F for ; Thu, 1 Aug 2019 11:27:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730809AbfHAL1K (ORCPT ); Thu, 1 Aug 2019 07:27:10 -0400 Received: from bhuna.collabora.co.uk ([46.235.227.227]:36746 "EHLO bhuna.collabora.co.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725790AbfHAL1K (ORCPT ); Thu, 1 Aug 2019 07:27:10 -0400 Received: from [127.0.0.1] (localhost [127.0.0.1]) (Authenticated sender: eballetbo) with ESMTPSA id 61C7C28C2DF Subject: Re: [PATCH 5/5] spi: Reduce kthread priority To: Peter Zijlstra , mingo@kernel.org Cc: linux-kernel@vger.kernel.org, Benson Leung , Guenter Roeck , Mark Brown , linux-spi@vger.kernel.org, Doug Anderson References: <20190801111348.530242235@infradead.org> <20190801111541.917256884@infradead.org> From: Enric Balletbo i Serra Message-ID: <640721f8-8a20-b161-473f-98a9dbc053cc@collabora.com> Date: Thu, 1 Aug 2019 13:27:04 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.8.0 MIME-Version: 1.0 In-Reply-To: <20190801111541.917256884@infradead.org> Content-Type: text/plain; charset=utf-8 Content-Language: en-GB Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org cc'ing Doug as he might be really interested on this patch On 1/8/19 13:13, Peter Zijlstra wrote: > The SPI thingies request FIFO-99 by default, reduce this to FIFO-50. > You say below that is not a suitable default but there is any other reason? Did you observed problems with this? > FIFO-99 is the very highest priority available to SCHED_FIFO and > it not a suitable default; it would indicate the SPI work is the > most important work on the machine. > > Cc: Benson Leung > Cc: Enric Balletbo i Serra > Cc: Guenter Roeck > Cc: Mark Brown > Cc: linux-spi@vger.kernel.org > Cc: linux-kernel@vger.kernel.org > Signed-off-by: Peter Zijlstra (Intel) > --- > drivers/platform/chrome/cros_ec_spi.c | 2 +- > drivers/spi/spi.c | 2 +- > 2 files changed, 2 insertions(+), 2 deletions(-) > > --- a/drivers/platform/chrome/cros_ec_spi.c > +++ b/drivers/platform/chrome/cros_ec_spi.c > @@ -706,7 +706,7 @@ static int cros_ec_spi_devm_high_pri_all > struct cros_ec_spi *ec_spi) > { > struct sched_param sched_priority = { > - .sched_priority = MAX_RT_PRIO - 1, > + .sched_priority = MAX_RT_PRIO / 2, > }; > int err; > > --- a/drivers/spi/spi.c > +++ b/drivers/spi/spi.c > @@ -1434,7 +1434,7 @@ static void spi_pump_messages(struct kth > */ > static void spi_set_thread_rt(struct spi_controller *ctlr) > { > - struct sched_param param = { .sched_priority = MAX_RT_PRIO - 1 }; > + struct sched_param param = { .sched_priority = MAX_RT_PRIO / 2 }; > > dev_info(&ctlr->dev, > "will run message pump with realtime priority\n"); > >