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=-3.6 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS 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 8AC1FC352A4 for ; Wed, 12 Feb 2020 21:14:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5E2AF206D7 for ; Wed, 12 Feb 2020 21:14:31 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="Uz44U9t2" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729265AbgBLVOa (ORCPT ); Wed, 12 Feb 2020 16:14:30 -0500 Received: from merlin.infradead.org ([205.233.59.134]:33480 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729198AbgBLVOO (ORCPT ); Wed, 12 Feb 2020 16:14:14 -0500 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=merlin.20170209; 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=MtLsQLaXADO+AZHxVktK/gN+oXBYn0ymRHkx9dI1F3k=; b=Uz44U9t2iYCgfqgExOEiwrMeZI 6X9awiCu6DPIxtRsoIZDg5DpXXWXhTgnZSLFJzVOgoLdAH1B/OO56E3L9k0zdDSWsk7emmdtdZY9B n9GUqKnH95dALIQ9zbbDajTwE0zsfP+SYYIFwV8nvlA1iXQ93QndsMU67hlIw1ZpvGryDWcNKlV3/ P+0CLRWtSxvzTG1KjdEKjjd44iJTfyLh3t7fbMYm/HelHc9Lb4L9tEl5R7/8bZAvweireWH9dB0VZ Qx0yzGUMnIQ5cax1GYYxeR0h+k+MPJ5ftVtpUDGTPu3BuiFleMweLTlTXla1iCHZJdiLqDAFoFLFs 70+Gu7uQ==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=noisy.programming.kicks-ass.net) by merlin.infradead.org with esmtpsa (Exim 4.92.3 #3 (Red Hat Linux)) id 1j1zKK-0002Ki-Jn; Wed, 12 Feb 2020 21:13:44 +0000 Received: from hirez.programming.kicks-ass.net (hirez.programming.kicks-ass.net [192.168.1.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id C1C2630700B; Wed, 12 Feb 2020 22:11:52 +0100 (CET) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 0) id 875D8203A89A0; Wed, 12 Feb 2020 22:13:41 +0100 (CET) Message-Id: <20200212210750.142334759@infradead.org> User-Agent: quilt/0.65 Date: Wed, 12 Feb 2020 22:01:45 +0100 From: Peter Zijlstra To: linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org, rostedt@goodmis.org Cc: peterz@infradead.org, mingo@kernel.org, joel@joelfernandes.org, gregkh@linuxfoundation.org, gustavo@embeddedor.com, tglx@linutronix.de, paulmck@kernel.org, josh@joshtriplett.org, mathieu.desnoyers@efficios.com, jiangshanlai@gmail.com, "Steven Rostedt (VMware)" Subject: [PATCH v2 6/9] perf,tracing: Prepare the perf-trace interface for RCU changes References: <20200212210139.382424693@infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The tracepoint interface will stop providing regular RCU context; make sure we do it ourselves, since perf makes use of regular RCU protected data. Suggested-by: Steven Rostedt (VMware) Suggested-by: Mathieu Desnoyers Signed-off-by: Peter Zijlstra (Intel) --- kernel/events/core.c | 5 +++++ 1 file changed, 5 insertions(+) --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -8950,6 +8950,7 @@ void perf_tp_event(u16 event_type, u64 c { struct perf_sample_data data; struct perf_event *event; + unsigned long rcu_flags; struct perf_raw_record raw = { .frag = { @@ -8961,6 +8962,8 @@ void perf_tp_event(u16 event_type, u64 c perf_sample_data_init(&data, 0, 0); data.raw = &raw; + rcu_flags = trace_rcu_enter(); + perf_trace_buf_update(record, event_type); hlist_for_each_entry_rcu(event, head, hlist_entry) { @@ -8996,6 +8999,8 @@ void perf_tp_event(u16 event_type, u64 c } perf_swevent_put_recursion_context(rctx); + + trace_rcu_exit(rcu_flags); } EXPORT_SYMBOL_GPL(perf_tp_event);