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=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,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 86C2BCA90AF for ; Wed, 13 May 2020 12:24:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5BC5223126 for ; Wed, 13 May 2020 12:24:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731480AbgEMMYo (ORCPT ); Wed, 13 May 2020 08:24:44 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45128 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726020AbgEMMYo (ORCPT ); Wed, 13 May 2020 08:24:44 -0400 Received: from Galois.linutronix.de (Galois.linutronix.de [IPv6:2a0a:51c0:0:12e:550::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3516EC061A0C for ; Wed, 13 May 2020 05:24:44 -0700 (PDT) Received: from p5de0bf0b.dip0.t-ipconnect.de ([93.224.191.11] helo=nanos.tec.linutronix.de) by Galois.linutronix.de with esmtpsa (TLS1.2:DHE_RSA_AES_256_CBC_SHA256:256) (Exim 4.80) (envelope-from ) id 1jYqRE-0002Bm-W7; Wed, 13 May 2020 14:24:41 +0200 Received: by nanos.tec.linutronix.de (Postfix, from userid 1000) id 68A72100605; Wed, 13 May 2020 14:24:40 +0200 (CEST) From: Thomas Gleixner To: Wojciech Kudla , linux-kernel@vger.kernel.org Cc: mingo@redhat.com, hpa@zytor.com, x86@kernel.org Subject: Re: x86/smp: adding new trace points In-Reply-To: References: <4d54953b-f968-63f5-569f-9e09bc0f361c@gmail.com> Date: Wed, 13 May 2020 14:24:40 +0200 Message-ID: <87y2pw2fav.fsf@nanos.tec.linutronix.de> MIME-Version: 1.0 Content-Type: text/plain X-Linutronix-Spam-Score: -1.0 X-Linutronix-Spam-Level: - X-Linutronix-Spam-Status: No , -1.0 points, 5.0 required, ALL_TRUSTED=-1,SHORTCIRCUIT=-0.0001 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Wojciech Kudla writes: > I was trying to trace some IPIs (remote tlb shootdowns in this case) and noticed that: > > 1) irq_vectors:x86_platform_ipi_entry and irq_vectors:x86_platform_ipi_exit are not hit at all for my case. The backtrace on the receiving CPU: > > 0xffffffff81079535 flush_tlb_func_common.constprop.10+0x105/0x220 [kernel] > 0xffffffff81079681 flush_tlb_func_remote+0x31/0x40 [kernel] > 0xffffffff8111f76c flush_smp_call_function_queue+0x4c/0xf0 [kernel] > 0xffffffff81120253 generic_smp_call_function_single_interrupt+0x13/0x30 [kernel] > 0xffffffff81a030c6 smp_call_function_single_interrupt+0x36/0xd0 [kernel] > 0xffffffff81a02679 call_function_single_interrupt+0xa9/0xb0 [kernel] > > I would expect that we would hit those trace point somewhere around > call_function_single_interrupt() Why would the SMP call function single interrupt go through the PLATFORM_IPI_VECTOR? It goes as the name says through the CALL_FUNCTION_SINGLE_VECTOR. Thanks, tglx