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 709CDC433EF for ; Tue, 15 Feb 2022 15:51:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241046AbiBOPwD (ORCPT ); Tue, 15 Feb 2022 10:52:03 -0500 Received: from mxb-00190b01.gslb.pphosted.com ([23.128.96.19]:51136 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232757AbiBOPwC (ORCPT ); Tue, 15 Feb 2022 10:52:02 -0500 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id CF8219BBB8 for ; Tue, 15 Feb 2022 07:51:51 -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=KbE1laj8zmpkZqMq0pcAt0X3XPM/5mSQfNe+PyZG60c=; b=oU4Q9WfHkNwHfdUH9FLPEWmrwP IJYlAljLn/AZx4lvXXy4pAhu6o52vD8PFuj7y/J9qiEEzzQxcMqpFtl7E8oZGFd101HOw8v96HY6u RTUUXsJYPuGoPJoeBUJV2NVgqLcolbHhILuX69HMzWdLnqW8p7iq34LXLvb/vUyynsISMMI2mM/TM FWZrHeUgPimbDIgH+d7QWOhaZIZ3i+AmHvJ0bvA6O13puvSlwZMsI+DVlLwlQuEOivedXzRSVbjQ6 YnyZiZlPISsQKoKvqIWf+abcoi+N9Hewfxs6eRb5FuwxYOMe/CnAPIX5oIJO1C2ie5zX2PK9oJ8Nu WXgiXCiw==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=noisy.programming.kicks-ass.net) by casper.infradead.org with esmtpsa (Exim 4.94.2 #2 (Red Hat Linux)) id 1nK079-00DyBd-50; Tue, 15 Feb 2022 15:51:39 +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 B39F63001C0; Tue, 15 Feb 2022 16:51:37 +0100 (CET) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 94170201E7FC2; Tue, 15 Feb 2022 16:51:37 +0100 (CET) Date: Tue, 15 Feb 2022 16:51:37 +0100 From: Peter Zijlstra To: Adrian Hunter Cc: Alexander Shishkin , Andi Kleen , Arnaldo Carvalho de Melo , Jiri Olsa , linux-kernel@vger.kernel.org, Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org, H Peter Anvin Subject: Re: [PATCH V2 0/2] perf/x86/intel/pt: Add support for event tracing and TNT disabling Message-ID: References: <20220126104815.2807416-1-adrian.hunter@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Feb 15, 2022 at 05:40:45PM +0200, Adrian Hunter wrote: > On 15/02/2022 17:35, Peter Zijlstra wrote: > > On Wed, Jan 26, 2022 at 12:48:13PM +0200, Adrian Hunter wrote: > >> Hi > >> > >> As of Intel SDM (https://www.intel.com/sdm) version 076, there are 2 new > >> Intel PT features called Event Trace and TNT-Disable. > >> > >> Event Trace exposes details about asynchronous events such as interrupts > >> and VM-Entry/Exit. > >> > >> TNT-Disable disables TNT packets to reduce the tracing overhead, but with > >> the result that exact control flow information is lost. > > > > What's a TNT? > > The TNT packet indicates whether conditional branches were taken > or not taken. Thanks, updated that Changelog.