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=-3.8 required=3.0 tests=BAYES_00, 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 21155C433E7 for ; Mon, 19 Oct 2020 10:21:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CBAFA22268 for ; Mon, 19 Oct 2020 10:21:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726510AbgJSKVi (ORCPT ); Mon, 19 Oct 2020 06:21:38 -0400 Received: from mailout05.rmx.de ([94.199.90.90]:43232 "EHLO mailout05.rmx.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726325AbgJSKVg (ORCPT ); Mon, 19 Oct 2020 06:21:36 -0400 Received: from kdin01.retarus.com (kdin01.dmz1.retloc [172.19.17.48]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mailout05.rmx.de (Postfix) with ESMTPS id 4CFCTm6QzMz9yVq; Mon, 19 Oct 2020 12:21:32 +0200 (CEST) Received: from mta.arri.de (unknown [217.111.95.66]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-SHA384 (256/256 bits)) (No client certificate requested) by kdin01.retarus.com (Postfix) with ESMTPS id 4CFCTQ21kpz2xqM; Mon, 19 Oct 2020 12:21:14 +0200 (CEST) Received: from n95hx1g2.localnet (192.168.54.91) by mta.arri.de (192.168.100.104) with Microsoft SMTP Server (TLS) id 14.3.408.0; Mon, 19 Oct 2020 12:21:07 +0200 From: Christian Eggers To: Sebastian Andrzej Siewior CC: Peter Zijlstra , , , Subject: sched: system doesn't boot since "sched: Add new migrate_disable() implementation" Date: Mon, 19 Oct 2020 12:21:06 +0200 Message-ID: <1654655.1jrfHnk7pZ@n95hx1g2> Organization: Arnold & Richter Cine Technik GmbH & Co. Betriebs KG MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" X-Originating-IP: [192.168.54.91] X-RMX-ID: 20201019-122118-4CFCTQ21kpz2xqM-0@kdin01 X-RMX-SOURCE: 217.111.95.66 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org I have problems with the latest 5.9-rt releases on i.MX6ULL (!CONFIG_SMP): -rc8-rt13 works fine -rc8-rt14 doesn't compile (due to CONFIG_FRACE, already fixed in -rt16) -rt15 dito. -rt16 compiles, but doesn't boot (no console output at all) After reverting (on -rt16) de1c0755e6f9 ("tracing: fix compile failure on RT with PREEMPT_RT off") 30763ce6c15d ("sched: Add new migrate_disable() implementation") the system boots fine again. Tracking the problem down showed that calls to wait_for_completion_timeout() (e.g. during imx_rngc_probe) will never return. The IRQ routine which should fire the completion is not executed, and the call doesn't return after the timeout. The IRQ flag on the ARM is not set before entering wait_for_completion_timeout(), so CPU interrupts seem to be on. When building with CONFIG_SMP, the system boots fine. Any hints? Best regards Christian