From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34982 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732878AbgFWPZc (ORCPT ); Tue, 23 Jun 2020 11:25:32 -0400 Date: Tue, 23 Jun 2020 17:24:50 +0200 From: Peter Zijlstra Subject: Re: [PATCH v4 7/8] lockdep: Change hardirq{s_enabled,_context} to per-cpu variables Message-ID: <20200623152450.GM4817@hirez.programming.kicks-ass.net> References: <20200623083645.277342609@infradead.org> <20200623083721.512673481@infradead.org> <20200623150031.GA2986783@debian-buster-darwi.lab.linutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200623150031.GA2986783@debian-buster-darwi.lab.linutronix.de> Sender: linux-s390-owner@vger.kernel.org List-ID: To: "Ahmed S. Darwish" Cc: mingo@kernel.org, will@kernel.org, tglx@linutronix.de, x86@kernel.org, linux-kernel@vger.kernel.org, rostedt@goodmis.org, bigeasy@linutronix.de, davem@davemloft.net, sparclinux@vger.kernel.org, mpe@ellerman.id.au, linuxppc-dev@lists.ozlabs.org, heiko.carstens@de.ibm.com, linux-s390@vger.kernel.org, linux@armlinux.org.uk On Tue, Jun 23, 2020 at 05:00:31PM +0200, Ahmed S. Darwish wrote: > On Tue, Jun 23, 2020 at 10:36:52AM +0200, Peter Zijlstra wrote: > ... > > -#define lockdep_assert_irqs_disabled() do { \ > > - WARN_ONCE(debug_locks && !current->lockdep_recursion && \ > > - current->hardirqs_enabled, \ > > - "IRQs not disabled as expected\n"); \ > > - } while (0) > > +#define lockdep_assert_irqs_enabled() \ > > +do { \ > > + WARN_ON_ONCE(debug_locks && !this_cpu_read(hardirqs_enabled)); \ > > +} while (0) > > > > Can we add a small comment on top of lockdep_off(), stating that lockdep > IRQ tracking will still be kept after a lockdep_off call? That would only legitimize lockdep_off(). The only comment I want to put on that is: "if you use this, you're doing it wrong'.