From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mike Galbraith Subject: Re: [PATCH v2 1/2] rtmutex Real-Time Linux: Fixing kernel BUG at kernel/locking/rtmutex.c:997! Date: Tue, 07 Apr 2015 13:47:16 +0200 Message-ID: <1428407236.3152.81.camel@gmail.com> References: <1424395866-81589-1-git-send-email-tmac@hp.com> <1428369962-74723-1-git-send-email-tmac@hp.com> <1428369962-74723-2-git-send-email-tmac@hp.com> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Cc: Thavatchai Makphaibulchoke , Steven Rostedt , LKML , mingo@redhat.com, linux-rt-users , Peter Zijlstra To: Thomas Gleixner Return-path: Received: from mail-wi0-f182.google.com ([209.85.212.182]:36085 "EHLO mail-wi0-f182.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752795AbbDGLrU (ORCPT ); Tue, 7 Apr 2015 07:47:20 -0400 In-Reply-To: Sender: linux-rt-users-owner@vger.kernel.org List-ID: On Tue, 2015-04-07 at 13:23 +0200, Thomas Gleixner wrote: > On Mon, 6 Apr 2015, Thavatchai Makphaibulchoke wrote: > > > This patch fixes the problem that the ownership of a mutex acquired > > by an interrupt handler(IH) gets incorrectly attributed to the > > interrupted thread. > > An hard interrupt handler is not allowed to take a mutex. End of > story, nothing to fix here. Well, the patch that started this thread.. timers-do-not-raise-softirq-unconditionally.patch ..(attributed to you) was picked up in -rt (perhaps erroneously) to get nohz_full working, and then reverted due to the deadlock detector getting properly angry. All of this is about reinstating it. I posted a patchlet to simply subtract softirqd from the ->nr_running check, which gets nohz_full working in -rt sans illegal activity. -Mike