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=-2.4 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 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 636B7C433DF for ; Tue, 26 May 2020 16:52:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D8D52207FB for ; Tue, 26 May 2020 16:52:39 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=firstfloor.org header.i=@firstfloor.org header.b="fB8VIFWC" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728339AbgEZQwj (ORCPT ); Tue, 26 May 2020 12:52:39 -0400 Received: from one.firstfloor.org ([193.170.194.197]:37812 "EHLO one.firstfloor.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727941AbgEZQwj (ORCPT ); Tue, 26 May 2020 12:52:39 -0400 X-Greylist: delayed 636 seconds by postgrey-1.27 at vger.kernel.org; Tue, 26 May 2020 12:52:38 EDT Received: by one.firstfloor.org (Postfix, from userid 503) id 44A098685E; Tue, 26 May 2020 18:42:00 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=firstfloor.org; s=mail; t=1590511320; bh=ypj4ICCsdXfcRKsp95D8F+u/CRhGalypVnmun5o9cJQ=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=fB8VIFWCBOwHm5CNqJZ8J/Nqb/aMn19iQofeb63Rl9nP8jWQT31B2Q1VORR8zi8wu ty9SM/4dkoimEA2CJr9RqeTVAH5FKEPVyR/IenBztcjgSSqlI7lZtzlBstz9cPl6Jp NOfO4fwVOSzNAEY9VPyrShlq4OjxfwUJboMVqPgg= Date: Tue, 26 May 2020 09:42:00 -0700 From: Andi Kleen To: Arnaldo Carvalho de Melo Cc: Steven Rostedt , Andi Kleen , Jin Yao , ahmadkhorrami , Linux-trace Users , linux-perf-users@vger.kernel.org, Arnaldo Carvalho de Melo Subject: Re: Perf Reports Jump Instructions as Memory Access Instructions Message-ID: <20200526164159.dsnboewwdyczr5j6@two.firstfloor.org> References: <20200526133817.GA23187@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200526133817.GA23187@redhat.com> User-Agent: NeoMutt/20170113 (1.7.2) Sender: linux-trace-users-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-trace-users@vger.kernel.org > > > The access point is at offset 0 of the following disassembly: > > Dump of assembler code for function cairo_surface_get_device_scale@plt: > > > 0x000000000002a310 <+0>: jmpq *0x2c8b3a(%rip) # 0x2f2e50 > > > 0x000000000002a316 <+6>: pushq $0x1c7 > > > 0x000000000002a31b <+11>: jmpq 0x28690 > > > > > > This is an unconditional jump which will not lead to macrofusion. > > But that will access memory, no? The instruction at offset 0. Instruction fetches are not sampled by the MEM_INST_RETIRED event. This is an indirect jump through memory, so it accesses the memory at 0x2c8b3a(%rip). These kind of accesses are sampled by the event. Other memory accesses as part of other instructions may be sampled too. -Andi