From patchwork Mon Jun 12 09:08:09 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Peter Zijlstra X-Patchwork-Id: 13276184 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 6558CC8300C for ; Mon, 12 Jun 2023 09:58:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229697AbjFLJ6Y (ORCPT ); Mon, 12 Jun 2023 05:58:24 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33438 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234161AbjFLJyv (ORCPT ); Mon, 12 Jun 2023 05:54:51 -0400 Received: from desiato.infradead.org (desiato.infradead.org [IPv6:2001:8b0:10b:1:d65d:64ff:fe57:4e05]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E857E114; Mon, 12 Jun 2023 02:39:21 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=desiato.20200630; h=Content-Type:MIME-Version:References: Subject:Cc:To:From:Date:Message-ID:Sender:Reply-To:Content-Transfer-Encoding: Content-ID:Content-Description:In-Reply-To; bh=LlQbmNANbazrx11NDWgZGA+KsXoINGT+PoaKYdOA2yY=; b=PVxnCtl+cg0H5werzmZktd2ptY izw9imbUtFY6WKlX5m+pXGI8jB2Vpexpx25d6HydeIPlUHTQH8vTmyDyJuvg9H7K/9mL+zKKa527w ZBj+oG2yYdaX7auomnWIzG6FKkjmmb6TDINrgGuaLPq5rr4E6e0kwgIvRJMOs0JzXBrxHXfD7oZ93 6voMlbWkgwNXry+eXUwyLqaXUDmJRoEaYdt0xbRcQWgi6eS/kSaMf2kt3cephuX+5Gvj7f+reovi2 GiDQhAzvnZWli9/XSIkjtId4Vy90oRY37gyAqxmCDQfV+zfvW9AmSLNfYexJVAAjoVuDoRQBHyiyi l5rs8tjA==; Received: from j130084.upc-j.chello.nl ([24.132.130.84] helo=noisy.programming.kicks-ass.net) by desiato.infradead.org with esmtpsa (Exim 4.96 #2 (Red Hat Linux)) id 1q8e0z-008kUm-1x; Mon, 12 Jun 2023 09:39:17 +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)) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id 7B04A30615D; Mon, 12 Jun 2023 11:38:53 +0200 (CEST) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 0) id 3CAAD30A7A29D; Mon, 12 Jun 2023 11:38:49 +0200 (CEST) Message-ID: <20230612093541.598260416@infradead.org> User-Agent: quilt/0.66 Date: Mon, 12 Jun 2023 11:08:09 +0200 From: Peter Zijlstra To: torvalds@linux-foundation.org, keescook@chromium.org, gregkh@linuxfoundation.org, pbonzini@redhat.com Cc: masahiroy@kernel.org, nathan@kernel.org, ndesaulniers@google.com, nicolas@fjasle.eu, catalin.marinas@arm.com, will@kernel.org, vkoul@kernel.org, trix@redhat.com, ojeda@kernel.org, peterz@infradead.org, mingo@redhat.com, longman@redhat.com, boqun.feng@gmail.com, dennis@kernel.org, tj@kernel.org, cl@linux.com, acme@kernel.org, mark.rutland@arm.com, alexander.shishkin@linux.intel.com, jolsa@kernel.org, namhyung@kernel.org, irogers@google.com, adrian.hunter@intel.com, juri.lelli@redhat.com, vincent.guittot@linaro.org, dietmar.eggemann@arm.com, rostedt@goodmis.org, bsegall@google.com, mgorman@suse.de, bristot@redhat.com, vschneid@redhat.com, paulmck@kernel.org, frederic@kernel.org, quic_neeraju@quicinc.com, joel@joelfernandes.org, josh@joshtriplett.org, mathieu.desnoyers@efficios.com, jiangshanlai@gmail.com, rientjes@google.com, vbabka@suse.cz, roman.gushchin@linux.dev, 42.hyeyoo@gmail.com, apw@canonical.com, joe@perches.com, dwaipayanray1@gmail.com, lukas.bulwahn@gmail.com, john.johansen@canonical.com, paul@paul-moore.com, jmorris@namei.org, serge@hallyn.com, linux-kbuild@vger.kernel.org, linux-kernel@vger.kernel.org, dmaengine@vger.kernel.org, llvm@lists.linux.dev, linux-perf-users@vger.kernel.org, rcu@vger.kernel.org, linux-security-module@vger.kernel.org, tglx@linutronix.de, ravi.bangoria@amd.com, error27@gmail.com, luc.vanoostenryck@gmail.com Subject: [PATCH v3 56/57] perf: Simplify perf_pmu_output_stop() References: <20230612090713.652690195@infradead.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: rcu@vger.kernel.org Signed-off-by: Peter Zijlstra (Intel) --- kernel/events/core.c | 8 +++----- 1 file changed, 3 insertions(+), 5 deletions(-) --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -7977,7 +7977,8 @@ static void perf_pmu_output_stop(struct int err, cpu; restart: - rcu_read_lock(); + /* cannot have a label in front of a decl */; + guard(rcu)(); list_for_each_entry_rcu(iter, &event->rb->event_list, rb_entry) { /* * For per-CPU events, we need to make sure that neither they @@ -7993,12 +7994,9 @@ static void perf_pmu_output_stop(struct continue; err = cpu_function_call(cpu, __perf_pmu_output_stop, event); - if (err == -EAGAIN) { - rcu_read_unlock(); + if (err == -EAGAIN) goto restart; - } } - rcu_read_unlock(); } /*