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=-2.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_PASS,T_DKIMWL_WL_HIGH,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 41627C433F4 for ; Tue, 28 Aug 2018 14:10:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id EEA872088E for ; Tue, 28 Aug 2018 14:10:52 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="OL24y125" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org EEA872088E Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.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 S1727945AbeH1SCl (ORCPT ); Tue, 28 Aug 2018 14:02:41 -0400 Received: from mail.kernel.org ([198.145.29.99]:44372 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727020AbeH1SCl (ORCPT ); Tue, 28 Aug 2018 14:02:41 -0400 Received: from jouet.infradead.org (unknown [190.15.121.82]) (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 E927C2088E; Tue, 28 Aug 2018 14:10:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1535465450; bh=2Vb66Cwc1DOT5mJ+0KAaKy/vfKUE43ekrYhNZ2WAWfg=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=OL24y12537hXrQP8FhWCwv7liS1a9riOkzxLP46SvLYp8FLWYnRKjoMpbA1nOrdN/ mNOPRNL6Sm/qNCKF142DwxltGLLwt1EVsLBT2/Sq9jzrKevM1YHtlgXxKMFjxL2oPZ 5dMp5VGKUD81hcnBcGqn21RmA5Jba/ASMnsiLlho= Received: by jouet.infradead.org (Postfix, from userid 1000) id 1A376141C3F; Tue, 28 Aug 2018 11:10:47 -0300 (-03) Date: Tue, 28 Aug 2018 11:10:47 -0300 From: Arnaldo Carvalho de Melo To: Martin =?utf-8?B?TGnFoWth?= Cc: linux-perf-users@vger.kernel.org, lkml , Jiri Olsa Subject: Re: [PATCH] Properly interpret indirect call in perf annotate. Message-ID: <20180828141047.GG22309@kernel.org> References: <20180823141219.GA4766@kernel.org> <64684c59-492c-3310-a5d2-14b467602acc@suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <64684c59-492c-3310-a5d2-14b467602acc@suse.cz> X-Url: http://acmel.wordpress.com User-Agent: Mutt/1.9.2 (2017-12-15) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Em Mon, Aug 27, 2018 at 11:06:21AM +0200, Martin Liška escreveu: > On 08/23/2018 04:12 PM, Arnaldo Carvalho de Melo wrote: > > Em Thu, Aug 23, 2018 at 02:29:34PM +0200, Martin Liška escreveu: > >> The patch changes interpretation of: > >> callq *0x8(%rbx) > >> > >> from: > >> 0.26 │ → callq *8 > >> to: > >> 0.26 │ → callq *0x8(%rbx) > >> > >> in this can an address is followed by a register, thus > >> one can't parse only address. > > > > Please mention one or two functions where such sequence appears, so that > > others can reproduce your before/after more quickly, > > Sure, there's self-contained example on can compile (-O2) and test. > It's following call in test function: > > test: > .LFB1: > .cfi_startproc > movq %rdi, %rax > subq $8, %rsp > .cfi_def_cfa_offset 16 > movq %rsi, %rdi > movq %rdx, %rsi > call *8(%rax) <---- here > cmpl $1, %eax > adcl $-1, %eax > addq $8, %rsp > .cfi_def_cfa_offset 8 > ret > .cfi_endproc Here I'm getting: Samples: 2K of event 'cycles:uppp', 4000 Hz, Event count (approx.): 1808551484 test /home/acme/c/perf-callq [Percent: local period] 0.17 │ mov %rdx,-0x28(%rbp) 0.58 │ mov -0x18(%rbp),%rax 7.90 │ mov 0x8(%rax),%rax 8.67 │ mov -0x28(%rbp),%rcx │ mov -0x20(%rbp),%rdx 0.08 │ mov %rcx,%rsi 6.28 │ mov %rdx,%rdi 10.50 │ → callq *%rax 1.67 │ mov %eax,-0x4(%rbp) 11.95 │ cmpl $0x0,-0x4(%rbp) 8.14 │ ↓ je 3d │ mov -0x4(%rbp),%eax │ sub $0x1,%eax │ ↓ jmp 42 │3d: mov $0x0,%eax 7.84 │42: leaveq │ ← retq Without the patch, will check if something changes with it. - Arnaldo