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=-5.7 required=3.0 tests=BAYES_00,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 F275CC2D0E4 for ; Tue, 17 Nov 2020 21:22:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8933B24181 for ; Tue, 17 Nov 2020 21:22:49 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=efficios.com header.i=@efficios.com header.b="Tw9cRcga" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727310AbgKQVW0 (ORCPT ); Tue, 17 Nov 2020 16:22:26 -0500 Received: from mail.efficios.com ([167.114.26.124]:45334 "EHLO mail.efficios.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726035AbgKQVWZ (ORCPT ); Tue, 17 Nov 2020 16:22:25 -0500 Received: from localhost (localhost [127.0.0.1]) by mail.efficios.com (Postfix) with ESMTP id 0C7E22E4533; Tue, 17 Nov 2020 16:22:24 -0500 (EST) 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 3HtepbJml7JF; Tue, 17 Nov 2020 16:22:23 -0500 (EST) Received: from localhost (localhost [127.0.0.1]) by mail.efficios.com (Postfix) with ESMTP id B5EC62E48B3; Tue, 17 Nov 2020 16:22:23 -0500 (EST) DKIM-Filter: OpenDKIM Filter v2.10.3 mail.efficios.com B5EC62E48B3 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=efficios.com; s=default; t=1605648143; bh=PXqhEjZMAdpGDq5EtZwgnWt5f+BNVFmPUhm3+bOyFR0=; h=Date:From:To:Message-ID:MIME-Version; b=Tw9cRcgaXPVyHKi40MN9iOSfhO5xKJRdw+VA7ggRRC9kzgjQzUdThFe5+tmMZR9EU QcyYpCQsDpuIMZzC9CmYz/lkoE9k6Fn/2gtOpXDZz0B/kBFyxEAFkNha42bOJfw01A mmQaUl3/Rfq6C3XLIxU5XvNXXiw32CsqAXnw61rn/5PT9ep/qaMS1jPzACOlG9PUoo 6Pud/t7/khyWU2zJDC/je8+2OI/9dyiM6SZT1qflMyymL8pXMKfx4SgL31j7tdF5S7 1DLMGpXwxKkGR/iSMK987WYTXWBp8mvdnBbI+AGGo6vkzwj9iocbO0bILppKDFmS8S VQz8sFI0pIicQ== 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 K29gqlNIp7JB; Tue, 17 Nov 2020 16:22:23 -0500 (EST) Received: from mail03.efficios.com (mail03.efficios.com [167.114.26.124]) by mail.efficios.com (Postfix) with ESMTP id A31222E48B2; Tue, 17 Nov 2020 16:22:23 -0500 (EST) Date: Tue, 17 Nov 2020 16:22:23 -0500 (EST) From: Mathieu Desnoyers To: rostedt Cc: linux-kernel , Matt Mullins , Ingo Molnar , Alexei Starovoitov , Daniel Borkmann , Dmitry Vyukov , Martin KaFai Lau , Song Liu , Yonghong Song , Andrii Nakryiko , John Fastabend , KP Singh , netdev , bpf , Kees Cook , Josh Poimboeuf , Peter Zijlstra Message-ID: <334460618.48609.1605648143566.JavaMail.zimbra@efficios.com> In-Reply-To: <20201117155851.0c915705@gandalf.local.home> References: <20201116175107.02db396d@gandalf.local.home> <47463878.48157.1605640510560.JavaMail.zimbra@efficios.com> <20201117142145.43194f1a@gandalf.local.home> <375636043.48251.1605642440621.JavaMail.zimbra@efficios.com> <20201117153451.3015c5c9@gandalf.local.home> <20201117155851.0c915705@gandalf.local.home> Subject: Re: [PATCH] tracepoint: Do not fail unregistering a probe due to memory allocation 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_3975 (ZimbraWebClient - FF82 (Linux)/8.8.15_GA_3975) Thread-Topic: tracepoint: Do not fail unregistering a probe due to memory allocation Thread-Index: UdsIJ96gFLhqXRumJL7PS/UT274UmA== Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org ----- On Nov 17, 2020, at 3:58 PM, rostedt rostedt@goodmis.org wrote: > On Tue, 17 Nov 2020 15:34:51 -0500 > Steven Rostedt wrote: [...] > If it comes down to not trusting calling a stub, I'll still keep the stub > logic in, and just add the following: If we don't call the stub, then there is no point in having the stub at all, and we should just compare to a constant value, e.g. 0x1UL. As far as I can recall, comparing with a small immediate constant is more efficient than comparing with a loaded value on many architectures. Thanks, Mathieu -- Mathieu Desnoyers EfficiOS Inc. http://www.efficios.com