From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754028AbdEKFtY (ORCPT ); Thu, 11 May 2017 01:49:24 -0400 Received: from ozlabs.org ([103.22.144.67]:34319 "EHLO ozlabs.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751208AbdEKFtX (ORCPT ); Thu, 11 May 2017 01:49:23 -0400 From: Michael Ellerman To: Thomas Gleixner Cc: LKML , Peter Zijlstra , Ingo Molnar , Steven Rostedt , Sebastian Siewior Subject: Re: [patch V2 24/24] cpu/hotplug: Convert hotplug locking to percpu rwsem In-Reply-To: References: <20170418170442.665445272@linutronix.de> <20170418170554.382344438@linutronix.de> <87o9v171dk.fsf@concordia.ellerman.id.au> User-Agent: Notmuch/0.21 (https://notmuchmail.org) Date: Thu, 11 May 2017 15:49:21 +1000 Message-ID: <87vap8hrj2.fsf@concordia.ellerman.id.au> MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Thomas Gleixner writes: > On Wed, 10 May 2017, Michael Ellerman wrote: > >> Thomas Gleixner writes: >> >> > @@ -130,6 +130,7 @@ void __static_key_slow_inc(struct static >> > * the all CPUs, for that to be serialized against CPU hot-plug >> > * we need to avoid CPUs coming online. >> > */ >> > + lockdep_assert_hotplug_held(); >> > jump_label_lock(); >> > if (atomic_read(&key->enabled) == 0) { >> > atomic_set(&key->enabled, -1); >> >> I seem to be hitting this assert from the ftrace event selftests, >> enabled at boot with CONFIG_FTRACE_STARTUP_TEST=y, using next-20170509 >> (on powerpc). >> >> The stupidly obvious (or perhaps obviously stupid) patch below fixes it: > > Kinda. There is more horror in that area lurking and I'm still trying to > figure out all the convoluted call pathes. OK thanks. cheers