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 675E4C433F5 for ; Wed, 15 Dec 2021 23:56:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232108AbhLOX4t (ORCPT ); Wed, 15 Dec 2021 18:56:49 -0500 Received: from st43p00im-ztfb10071701.me.com ([17.58.63.173]:51168 "EHLO st43p00im-ztfb10071701.me.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232079AbhLOX4s (ORCPT ); Wed, 15 Dec 2021 18:56:48 -0500 X-Greylist: delayed 575 seconds by postgrey-1.27 at vger.kernel.org; Wed, 15 Dec 2021 18:56:48 EST DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=me.com; s=1a1hai; t=1639612033; bh=nabJC3GdjoIrUeYiQY+wdpND8yaRU8eF0J3qCFIkJHI=; h=From:Content-Type:Mime-Version:Subject:Message-Id:Date:To; b=heza7IPpQGOtXfhQ/+mEElhzjeuPLs+qWmg/LzyiJirGa9uV+OCgVsFzofG2JgUY2 lW5AtZn5pB+nCbe6Vg/CXsQmN5c4w7aQFW2uo8l6zhwo/YB3JT3p9NMLwQqAi8+3Nv lV+6+NjJ3P7VlO9CKQ98C58Z0i9y95xiInNrN8d6skw9Va7vRgPZeQEmEhmOPgSlJz oD+7H/1l6MUOOvrQ1Xi7xkEVFI+nle3vlObYYwxDOGkNQVmUWc4z4h3cFzUMpVeOBy KH0yyhRhALLnaWt43O18QxyVgb/NeP92T6ebS+KSNd4PqCY5EDdkD9c3TEFCTNi13j 8+I9cwjlWRVFw== Received: from smtpclient.apple (cpe-66-24-82-52.stny.res.rr.com [66.24.82.52]) by st43p00im-ztfb10071701.me.com (Postfix) with ESMTPSA id 3606E8A069C for ; Wed, 15 Dec 2021 23:47:13 +0000 (UTC) From: Timothy Miller Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Mime-Version: 1.0 (Mac OS X Mail 14.0 \(3654.120.0.1.13\)) Subject: perf not showing me call graph for memcpy no matter what. Message-Id: <4296BD20-DEBC-4A20-ACF0-EE46A1AD20CC@me.com> Date: Wed, 15 Dec 2021 18:47:12 -0500 To: linux-perf-users@vger.kernel.org X-Mailer: Apple Mail (2.3654.120.0.1.13) X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.425,18.0.790 definitions=2021-12-15_09:2021-12-13,2021-12-15 signatures=0 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 suspectscore=0 malwarescore=0 phishscore=0 bulkscore=0 spamscore=0 clxscore=1011 mlxscore=0 mlxlogscore=600 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-2009150000 definitions=main-2112150129 Precedence: bulk List-ID: X-Mailing-List: linux-perf-users@vger.kernel.org Hi, I am doing some software profiling on an aarch64 system, and I=E2=80=99m = using the Linux perf tool. The problem I=E2=80=99m running into is that = =E2=80=9C__GI___memcpy_simd=E2=80=9D keeps showing up as the function = with the most CPU usage. Unfortunately, no matter what I do, this function keeps showing up as = orphaned. That is, I cannot get a stack trace for it so I can find out = who is calling it. I have tried using dwarf mode, but it always gets overloaded. I have tried using lbr mode, but I get the following error: Error: PMU Hardware doesn't support sampling/overflow-interrupts. I=E2=80=99ve rebuilt my application and all relevant libraries with = -no-omit-frame-pointer so that I could use the default frame pointer = mode. Unfortunately, I still can=E2=80=99t get a call graph for this = function. I emailed the glibc mailing list about this, trying to find out how to = work around this problem, perhaps adding frame pointer to the assembly = implementation of memcpy. They suggested I try attaching a debugger, and = I=E2=80=99ve found that I can get stack traces just fine. They suggest = that I seem to be running into some kind of bug in perf.=20 Any help/advice would be appreciated. Thanks.=