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=-2.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_2 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 23ED1C352A3 for ; Mon, 10 Feb 2020 17:05:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id F0BA420842 for ; Mon, 10 Feb 2020 17:05:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727961AbgBJRF4 (ORCPT ); Mon, 10 Feb 2020 12:05:56 -0500 Received: from mail.kernel.org ([198.145.29.99]:46692 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727558AbgBJRFz (ORCPT ); Mon, 10 Feb 2020 12:05:55 -0500 Received: from gandalf.local.home (cpe-66-24-58-225.stny.res.rr.com [66.24.58.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id F364120838; Mon, 10 Feb 2020 17:05:53 +0000 (UTC) Date: Mon, 10 Feb 2020 12:05:52 -0500 From: Steven Rostedt To: Peter Zijlstra Cc: Mathieu Desnoyers , "Joel Fernandes, Google" , linux-kernel , Greg Kroah-Hartman , "Gustavo A. R. Silva" , Ingo Molnar , Richard Fontana , Thomas Gleixner , paulmck , Josh Triplett , Lai Jiangshan , Arnaldo Carvalho de Melo Subject: Re: [RFC 0/3] Revert SRCU from tracepoint infrastructure Message-ID: <20200210120552.1a06a7aa@gandalf.local.home> In-Reply-To: <20200210094616.GC14879@hirez.programming.kicks-ass.net> References: <20200207205656.61938-1-joel@joelfernandes.org> <1997032737.615438.1581179485507.JavaMail.zimbra@efficios.com> <20200210094616.GC14879@hirez.programming.kicks-ass.net> X-Mailer: Claws Mail 3.17.3 (GTK+ 2.24.32; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 10 Feb 2020 10:46:16 +0100 Peter Zijlstra wrote: > Furthermore, using srcu would be detrimental, because of how it has > smp_mb() in the read side primitives. I didn't realize that there was a full memory barrier in the srcu read side. Seems to me that itself is rational for reverting it. And also a big NAK for any suggestion to have any of the function tracing to use it as well (which comes up here and there). -- Steve