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=-0.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED 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 C0F2DC433DF for ; Wed, 13 May 2020 23:46:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C6FA720575 for ; Wed, 13 May 2020 23:46:42 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=efficios.com header.i=@efficios.com header.b="QpyHdQtq" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732769AbgEMXql (ORCPT ); Wed, 13 May 2020 19:46:41 -0400 Received: from mail.efficios.com ([167.114.26.124]:46456 "EHLO mail.efficios.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732456AbgEMXql (ORCPT ); Wed, 13 May 2020 19:46:41 -0400 Received: from localhost (localhost [127.0.0.1]) by mail.efficios.com (Postfix) with ESMTP id 25E232BFCD6; Wed, 13 May 2020 19:46:40 -0400 (EDT) Received: from mail.efficios.com ([127.0.0.1]) by localhost (mail03.efficios.com [127.0.0.1]) (amavisd-new, port 10032) with ESMTP id zdyYnyxu1i5k; Wed, 13 May 2020 19:46:39 -0400 (EDT) Received: from localhost (localhost [127.0.0.1]) by mail.efficios.com (Postfix) with ESMTP id CF8D62BFF55; Wed, 13 May 2020 19:46:39 -0400 (EDT) DKIM-Filter: OpenDKIM Filter v2.10.3 mail.efficios.com CF8D62BFF55 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=efficios.com; s=default; t=1589413599; bh=hYcJuwIbx5ygOgCVc4s7f4GT06EL6D/GrL5te5eHrR4=; h=Date:From:To:Message-ID:MIME-Version; b=QpyHdQtqi4lW/p9NpFAY6WR5+Zzk3BsHT6s4s8XncXqwsLApkuBgsat64EeHiKpuS Y8/bHOaq6OTeNVq2ULfXc0pn5SDujrvYBsblYX2Myi235K5bPGsYgToqPVprjCnX5W xZJFTpWUhp90ohMI0srTHoM5MsqHe+bGpko/6zp4sxsg0gqysmyLVEhNzOmIMrN7MX getvc0RnuRM9ZjPlW9qNAsVV0o7bdpLbF8cvIZHN8LXKukt6O9LfZZ2ZH+VPp4Uchn LmZuObFe5D4UKp5SE0ZSNTGTnw8wAtqII7ImOZBPiFZvkd4AGcRyvIU40P/b5oeHq6 SxH1wnNuouoJg== X-Virus-Scanned: amavisd-new at efficios.com Received: from mail.efficios.com ([127.0.0.1]) by localhost (mail03.efficios.com [127.0.0.1]) (amavisd-new, port 10026) with ESMTP id aONHcFiVDbEL; Wed, 13 May 2020 19:46:39 -0400 (EDT) Received: from mail03.efficios.com (mail03.efficios.com [167.114.26.124]) by mail.efficios.com (Postfix) with ESMTP id BBD342BFE29; Wed, 13 May 2020 19:46:39 -0400 (EDT) Date: Wed, 13 May 2020 19:46:39 -0400 (EDT) From: Mathieu Desnoyers To: Thomas Gleixner Cc: linux-kernel , x86 , paulmck , Andy Lutomirski , Alexandre Chartre , Frederic Weisbecker , Paolo Bonzini , Sean Christopherson , Masami Hiramatsu , Petr Mladek , rostedt , "Joel Fernandes, Google" , Boris Ostrovsky , Juergen Gross , Brian Gerst , Josh Poimboeuf , Will Deacon , Peter Zijlstra Message-ID: <365632030.20393.1589413599743.JavaMail.zimbra@efficios.com> In-Reply-To: <20200505134101.048523500@linutronix.de> References: <20200505131602.633487962@linutronix.de> <20200505134101.048523500@linutronix.de> Subject: Re: [patch V4 part 1 30/36] lockdep: Always inline lockdep_{off,on}() MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit X-Originating-IP: [167.114.26.124] X-Mailer: Zimbra 8.8.15_GA_3928 (ZimbraWebClient - FF76 (Linux)/8.8.15_GA_3928) Thread-Topic: lockdep: Always inline lockdep_{off,on}() Thread-Index: v1XMf2ohSUFR6Yptr41TJyRdxIX6Cg== Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org ----- On May 5, 2020, at 9:16 AM, Thomas Gleixner tglx@linutronix.de wrote: [...] > + * Split the recrursion counter in two to readily detect 'off' vs recursion. recrursion -> recursion > + */ > +#define LOCKDEP_RECURSION_BITS 16 > +#define LOCKDEP_OFF (1U << LOCKDEP_RECURSION_BITS) > +#define LOCKDEP_RECURSION_MASK (LOCKDEP_OFF - 1) > + > +/* > + * lockdep_{off,on}() are macros to avoid tracing and kprobes; not inlines due > + * to header dependencies. > + */ > + > +#define lockdep_off() \ > +do { \ > + current->lockdep_recursion += LOCKDEP_OFF; \ > +} while (0) > + > +#define lockdep_on() \ > +do { \ > + current->lockdep_recursion -= LOCKDEP_OFF; \ > +} while (0) Now that those on/off are macros rather than functions, I wonder if adding compiler barriers would be relevant ? Thanks, Mathieu > > extern void lockdep_register_key(struct lock_class_key *key); > extern void lockdep_unregister_key(struct lock_class_key *key); > --- a/kernel/locking/lockdep.c > +++ b/kernel/locking/lockdep.c > @@ -393,25 +393,6 @@ void lockdep_init_task(struct task_struc > task->lockdep_recursion = 0; > } > > -/* > - * Split the recrursion counter in two to readily detect 'off' vs recursion. > - */ > -#define LOCKDEP_RECURSION_BITS 16 > -#define LOCKDEP_OFF (1U << LOCKDEP_RECURSION_BITS) > -#define LOCKDEP_RECURSION_MASK (LOCKDEP_OFF - 1) > - > -void lockdep_off(void) > -{ > - current->lockdep_recursion += LOCKDEP_OFF; > -} > -EXPORT_SYMBOL(lockdep_off); > - > -void lockdep_on(void) > -{ > - current->lockdep_recursion -= LOCKDEP_OFF; > -} > -EXPORT_SYMBOL(lockdep_on); > - > static inline void lockdep_recursion_finish(void) > { > if (WARN_ON_ONCE(--current->lockdep_recursion)) -- Mathieu Desnoyers EfficiOS Inc. http://www.efficios.com