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=-4.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_PASS autolearn=ham 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 CFF3AC04EB9 for ; Wed, 5 Dec 2018 17:35:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9724820879 for ; Wed, 5 Dec 2018 17:35:08 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 9724820879 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=goodmis.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727953AbeLERfH (ORCPT ); Wed, 5 Dec 2018 12:35:07 -0500 Received: from mail.kernel.org ([198.145.29.99]:54522 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727429AbeLERfG (ORCPT ); Wed, 5 Dec 2018 12:35:06 -0500 Received: from vmware.local.home (unknown [208.91.3.26]) (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 12FB5206B7; Wed, 5 Dec 2018 17:35:06 +0000 (UTC) Date: Wed, 5 Dec 2018 12:35:03 -0500 From: Steven Rostedt To: Jiri Olsa Cc: Arnaldo Carvalho de Melo , Peter Zijlstra , lkml , Ingo Molnar , Namhyung Kim , Alexander Shishkin , Thomas Gleixner , "Luis Claudio R. Goncalves" , ldv@altlinux.org, esyr@redhat.com, Frederic Weisbecker Subject: Re: [PATCH 1/8] perf: Allow to block process in syscall tracepoints Message-ID: <20181205123503.4b8e0484@vmware.local.home> In-Reply-To: <20181205160509.1168-2-jolsa@kernel.org> References: <20181205160509.1168-1-jolsa@kernel.org> <20181205160509.1168-2-jolsa@kernel.org> X-Mailer: Claws Mail 3.15.1 (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 Wed, 5 Dec 2018 17:05:02 +0100 Jiri Olsa wrote: > diff --git a/arch/x86/entry/common.c b/arch/x86/entry/common.c > index 3b2490b81918..e55cf9169a03 100644 > --- a/arch/x86/entry/common.c > +++ b/arch/x86/entry/common.c > @@ -60,6 +60,32 @@ static void do_audit_syscall_entry(struct pt_regs *regs, u32 arch) > } > } > > +static void trace_block_syscall(struct pt_regs *regs, bool enter) > +{ > + current->perf_blocked = true; > + > + do { > + schedule_timeout(100 * HZ); > + current->perf_blocked_cnt = 0; > + > + if (enter) { > + /* perf syscalls:* enter */ > + perf_trace_syscall_enter(regs); > + > + /* perf raw_syscalls:* enter */ > + perf_trace_sys_enter(&event_sys_enter, regs, regs->orig_ax); > + } else { > + /* perf syscalls:* enter */ > + perf_trace_syscall_exit(regs); > + > + /* perf raw_syscalls:* enter */ > + perf_trace_sys_exit(&event_sys_exit, regs, regs->ax); > + } > + } while (current->perf_blocked_cnt); I was thinking, if the process reading the perf buffer dies, how do we tell this task to continue on? -- Steve > + > + current->perf_blocked = false; > +} > +