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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 95CE7C54EAA for ; Tue, 24 Jan 2023 14:45:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234609AbjAXOpg (ORCPT ); Tue, 24 Jan 2023 09:45:36 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58514 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233936AbjAXOpf (ORCPT ); Tue, 24 Jan 2023 09:45:35 -0500 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id EE69F1BDB; Tue, 24 Jan 2023 06:45:33 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=eA3jWjQCsaXuex737PYn1zrT0M5qTbaDIBSPCUlVDsw=; b=i0YMl4H0Tpp+J+qXHd3MZ+ZHEI hs/7dJiIdRGD0/TiQGg0NFONmko92fDUJ4AubYMGqa6gc0agQlfzopu+pWMdZnnzKxwccufwMIYrU ClpQiGyv6OLZGvM7WorTpI/EaX1kSWeiy/6PEw75g19P1+p2e6RSfFbOotaQ06+fX2/cgL/FtfbtZ aiAcxPawZOuKyHHRyVYxomM3UzUeqHVNlOnHa7540fgMhqgZs2d7+jxX3LOwTmArB7v7VySuvOcaW jCAUeGZxAuKc46C/X36RB0qw19xOwBay+soy3RV1jEhInSalJCtjqI1VOajgawdVUvrJNFvucjDHQ zMyhMRrQ==; Received: from j130084.upc-j.chello.nl ([24.132.130.84] helo=noisy.programming.kicks-ass.net) by casper.infradead.org with esmtpsa (Exim 4.94.2 #2 (Red Hat Linux)) id 1pKKXO-0057eL-0Z; Tue, 24 Jan 2023 14:44:38 +0000 Received: from hirez.programming.kicks-ass.net (hirez.programming.kicks-ass.net [192.168.1.225]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id 415DE30036B; Tue, 24 Jan 2023 15:44:35 +0100 (CET) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 26A232C217298; Tue, 24 Jan 2023 15:44:35 +0100 (CET) Date: Tue, 24 Jan 2023 15:44:35 +0100 From: Peter Zijlstra To: Steven Rostedt Cc: mingo@kernel.org, will@kernel.org, boqun.feng@gmail.com, mark.rutland@arm.com, tglx@linutronix.de, bp@alien8.de, dave.hansen@linux.intel.com, x86@kernel.org, hpa@zytor.com, seanjc@google.com, pbonzini@redhat.com, jgross@suse.com, srivatsa@csail.mit.edu, amakhalov@vmware.com, pv-drivers@vmware.com, mhiramat@kernel.org, wanpengli@tencent.com, vkuznets@redhat.com, boris.ostrovsky@oracle.com, rafael@kernel.org, daniel.lezcano@linaro.org, juri.lelli@redhat.com, vincent.guittot@linaro.org, dietmar.eggemann@arm.com, bsegall@google.com, mgorman@suse.de, bristot@redhat.com, vschneid@redhat.com, linux-kernel@vger.kernel.org, kvm@vger.kernel.org, virtualization@lists.linux-foundation.org, linux-trace-kernel@vger.kernel.org, linux-pm@vger.kernel.org Subject: Re: [PATCH 3/6] ftrace/x86: Warn and ignore graph tracing when RCU is disabled Message-ID: References: <20230123205009.790550642@infradead.org> <20230123205515.059999893@infradead.org> <20230123165304.370121e7@gandalf.local.home> <20230123170753.7ac9419e@gandalf.local.home> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20230123170753.7ac9419e@gandalf.local.home> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Jan 23, 2023 at 05:07:53PM -0500, Steven Rostedt wrote: > Actually, perhaps we can just add this, and all you need to do is create > and set CONFIG_NO_RCU_TRACING (or some other name). Elsewhere I've used CONFIG_ARCH_WANTS_NO_INSTR for this. Anyway, I took it for a spin and it .... doesn't seems to do the job. With my patch the first splat is "RCU not on for: cpuidle_poll_time+0x0/0x70" While with yours I seems to get the endless: "WARNING: suspicious RCU usage" thing. Let me see if I can figure out where it goes side-ways.