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=-2.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_2 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 854D4C11D30 for ; Mon, 24 Feb 2020 15:31:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5DCC620828 for ; Mon, 24 Feb 2020 15:31:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1582558272; bh=6nw4Wh11lpnEtqX0aH/aaIrhLA2Xtrbkwjh0ZyZP2as=; h=Subject:From:To:Cc:Date:In-Reply-To:References:List-ID:From; b=E3Ys55Q8dM0H+0BEssTSUEjkofsXZ5USgBoBgwXmx2BejXGEHsHK07kKodDhhIFZo 86Gl8mTF+1vBN1qOPmy+bGQ37OslX2gaCa8Y9wT3LGjRcZD5W1+r71urdVho3uHlhh h12XBs2HYAB6FGJ7WtT77bFJAGuxEC4xDf+/gmUg= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727803AbgBXPbI (ORCPT ); Mon, 24 Feb 2020 10:31:08 -0500 Received: from mail.kernel.org ([198.145.29.99]:47746 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727359AbgBXPbI (ORCPT ); Mon, 24 Feb 2020 10:31:08 -0500 Received: from tzanussi-mobl7 (c-98-220-238-81.hsd1.il.comcast.net [98.220.238.81]) (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 EFC8F20714; Mon, 24 Feb 2020 15:31:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1582558267; bh=6nw4Wh11lpnEtqX0aH/aaIrhLA2Xtrbkwjh0ZyZP2as=; h=Subject:From:To:Cc:Date:In-Reply-To:References:From; b=xNm5aVd2+DfQ5YJLQHGx16shVQvO9CFQ8cUn6H+2PYHkktqW7jUvuUhcXau+sgXbs 64pDgesTJNzbArd3WFsoQZrWNOtjkC8cMsg9EwJ1eMerR79WBW1ujQ7IjWkCsUsjjl Po10WmZRVbW5DZlbrXMPruw6YuMHChdNqENEgnQQ= Message-ID: <1582558266.12738.32.camel@kernel.org> Subject: Re: [PATCH RT 15/25] sched: migrate_enable: Use select_fallback_rq() From: Tom Zanussi To: Sebastian Andrzej Siewior Cc: LKML , linux-rt-users , Steven Rostedt , Thomas Gleixner , Carsten Emde , John Kacur , Daniel Wagner Date: Mon, 24 Feb 2020 09:31:06 -0600 In-Reply-To: <20200224094349.5x6dca4tggtmmbnq@linutronix.de> References: <20200224094349.5x6dca4tggtmmbnq@linutronix.de> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.26.1-1 Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-rt-users-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-rt-users@vger.kernel.org On Mon, 2020-02-24 at 10:43 +0100, Sebastian Andrzej Siewior wrote: > On 2020-02-21 15:24:43 [-0600], zanussi@kernel.org wrote: > > From: Scott Wood > > > > v4.14.170-rt75-rc1 stable review patch. > > If anyone has any objections, please let me know. > > This creates bug which is stuffed later via > sched: migrate_enable: Busy loop until the migration request is > completed > > So if apply this, please take the bug fix, too. This is Stevens queue > for reference: > > [PATCH RT 22/30] sched: migrate_enable: Use select_fallback_rq() > > ^^ bug introduced > Hmm, it seemed from the comment on the 4.19 series that it was '24/32 sched: migrate_enable: Use stop_one_cpu_nowait()' that required 'sched: migrate_enable: Busy loop until the migration request is completed' as a bug fix. https://lore.kernel.org/linux-rt-users/20200122083130.kuu3yppckhyjrr4u@linutronix.de/#t I didn't take the stop_one_cpu_nowait() one, so didn't take the busy loop one either. Thanks, Tom > > [PATCH RT 23/30] sched: Lazy migrate_disable > > processing > > > > [PATCH RT 24/30] sched: migrate_enable: Use stop_one_cpu_nowait() > > [PATCH RT 25/30] Revert "ARM: Initialize split page table locks for > > vector page" > > [PATCH RT 26/30] locking: Make spinlock_t and rwlock_t a RCU > > section on RT > > [PATCH RT 27/30] sched/core: migrate_enable() must access > > takedown_cpu_task on !HOTPLUG_CPU > > [PATCH RT 28/30] lib/smp_processor_id: Adjust > > check_preemption_disabled() > > [PATCH RT 29/30] sched: migrate_enable: Busy loop until the > > migration request is completed > > ^^ bug fixed > > Sebastian