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=-2.2 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_MUTT 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 9AA70C65BAE for ; Thu, 13 Dec 2018 10:08:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5B07220989 for ; Thu, 13 Dec 2018 10:08:23 +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="rENiGhGj" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 5B07220989 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.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 S1728150AbeLMKIW (ORCPT ); Thu, 13 Dec 2018 05:08:22 -0500 Received: from bombadil.infradead.org ([198.137.202.133]:46374 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727489AbeLMKIV (ORCPT ); Thu, 13 Dec 2018 05:08:21 -0500 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.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:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=QEGS9UZIzTSKcv9u0r4X/A1K8VcJujXRQzgKL+31vyk=; b=rENiGhGj1IdrDSLougaZd45hN fNGeYgWivWTswqfeYd3jJjmwiSQK+7N76rKAYcnD2jM+VMYVZMYI78eBkqFo+m1U2o3dJEB2pB9ai CuVkKbpiT9Gj98CtwnoanB1a2ac6MT0JHW6yzzOes64B8q96BQaFhfG5gCAz9YjYuAQxeIoIG44tQ mJDYt5Fm5o6Euikm1FrCGLTwUcDMBe4PFfNb7o1uMnBFMM4s+YN+tizXqOLBRFNMJYdkIAG0NIDYS IZSXmrqg6rX4JdiGihYbaJwzC27JktJh/c//oQYnEUJWvRm11ddOZKkurArvxr0LPPw1VG9XRbVoN izJY0DGiw==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=hirez.programming.kicks-ass.net) by bombadil.infradead.org with esmtpsa (Exim 4.90_1 #2 (Red Hat Linux)) id 1gXNuk-0008Kp-4J; Thu, 13 Dec 2018 10:08:18 +0000 Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id A26EA207261FE; Thu, 13 Dec 2018 11:08:16 +0100 (CET) Date: Thu, 13 Dec 2018 11:08:16 +0100 From: Peter Zijlstra To: Steven Rostedt Cc: "Dmitry V. Levin" , Jiri Olsa , Arnaldo Carvalho de Melo , Ingo Molnar , Namhyung Kim , Alexander Shishkin , Thomas Gleixner , "Luis Claudio R. Goncalves" , Eugene Syromyatnikov , Frederic Weisbecker , lkml Subject: Re: [PATCH 1/8] perf: Allow to block process in syscall tracepoints Message-ID: <20181213100816.GC5307@hirez.programming.kicks-ass.net> References: <20181207085839.GC2237@hirez.programming.kicks-ass.net> <20181207072701.5bc564c7@vmware.local.home> <20181207151105.GB5289@hirez.programming.kicks-ass.net> <20181207151433.20bf0399@vmware.local.home> <20181208104423.GE5289@hirez.programming.kicks-ass.net> <20181208123805.1c158665@vmware.local.home> <20181210101818.GJ5289@hirez.programming.kicks-ass.net> <20181213003938.GD24195@altlinux.org> <20181212202639.1978ec88@vmware.local.home> <20181213100149.GF5289@hirez.programming.kicks-ass.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20181213100149.GF5289@hirez.programming.kicks-ass.net> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Dec 13, 2018 at 11:01:49AM +0100, Peter Zijlstra wrote: > - the wakeups side is icky; the best I can come up with is making the > data page R/O and single stepping on write fault, but that isn't > multi-threading safe. We can emulate the instruction, that would actually work and be thread safe. Just a small matter of decoding and interpreting any possible write instruction ;-)