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=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no 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 53D68C33CB1 for ; Wed, 15 Jan 2020 14:43:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 22A932075B for ; Wed, 15 Jan 2020 14:43:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729076AbgAOOne convert rfc822-to-8bit (ORCPT ); Wed, 15 Jan 2020 09:43:34 -0500 Received: from eu-smtp-delivery-151.mimecast.com ([146.101.78.151]:33723 "EHLO eu-smtp-delivery-151.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729037AbgAOOnd (ORCPT ); Wed, 15 Jan 2020 09:43:33 -0500 Received: from AcuMS.aculab.com (156.67.243.126 [156.67.243.126]) (Using TLS) by relay.mimecast.com with ESMTP id uk-mta-231-IfFknEpZP0yJZA75H2odGA-1; Wed, 15 Jan 2020 14:43:27 +0000 Received: from AcuMS.Aculab.com (fd9f:af1c:a25b:0:43c:695e:880f:8750) by AcuMS.aculab.com (fd9f:af1c:a25b:0:43c:695e:880f:8750) with Microsoft SMTP Server (TLS) id 15.0.1347.2; Wed, 15 Jan 2020 14:43:26 +0000 Received: from AcuMS.Aculab.com ([fe80::43c:695e:880f:8750]) by AcuMS.aculab.com ([fe80::43c:695e:880f:8750%12]) with mapi id 15.00.1347.000; Wed, 15 Jan 2020 14:43:26 +0000 From: David Laight To: 'Steven Rostedt' CC: 'Vincent Guittot' , Peter Zijlstra , Viresh Kumar , Ingo Molnar , Juri Lelli , Dietmar Eggemann , Ben Segall , Mel Gorman , linux-kernel Subject: RE: sched/fair: scheduler not running high priority process on idle cpu Thread-Topic: sched/fair: scheduler not running high priority process on idle cpu Thread-Index: AdXK8cUFXa7JpPXmQNq7oQ32S9fYHAACik4AAADJLkAAAO3PAAAmXEggAAKDBAAAArEnQA== Date: Wed, 15 Jan 2020 14:43:26 +0000 Message-ID: <8421d8b6749c47d0a5519ddff5422e68@AcuMS.aculab.com> References: <212fabd759b0486aa8df588477acf6d0@AcuMS.aculab.com> <20200114115906.22f952ff@gandalf.local.home> <5ba2ae2d426c4058b314c20c25a9b1d0@AcuMS.aculab.com> <20200114124812.4d5355ae@gandalf.local.home> <878a35a6642d482aa0770a055506bd5e@AcuMS.aculab.com> <20200115081830.036ade4e@gandalf.local.home> In-Reply-To: <20200115081830.036ade4e@gandalf.local.home> Accept-Language: en-GB, en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-ms-exchange-transport-fromentityheader: Hosted x-originating-ip: [10.202.205.107] MIME-Version: 1.0 X-MC-Unique: IfFknEpZP0yJZA75H2odGA-1 X-Mimecast-Spam-Score: 0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Steven Rostedt > Sent: 15 January 2020 13:19 ... > BTW, I believe distros compile with "CONFIG_IRQ_FORCED_THREADING" which > means if you add to the kernel command line "threadirqs" the interrupts > will be run as threads. Which allows for even more preemption. So they do... I guess that'll stop the bh code running 'on top of' my RT thread. But won't help getting the RT process running when the 'events_unbound' kernel worker is running. They also use grub2 which is so complicated update-grub is always used which dumbs everything down to a default set that is hard to change. David - Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK Registration No: 1397386 (Wales)