From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id F3834848C for ; Fri, 26 Jul 2024 01:37:07 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1721957828; cv=none; b=aooXhi6tu8LxggIu9Kd7K+fKOk7n/r8PfoZi/m8MdKm2D+Ov9vZRqC/prZO1r6TTXHHqePeXeGByeB4BOknfnolKuqjcTei7IURN6QGT4ODC25a4iQJTFAj9QDBn/yDjutOSKZWojMlIPHw3yx29TIObKjbZ0pFDWvW5XGIvmao= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1721957828; c=relaxed/simple; bh=HZeRnqI2Oykvkscalx44mKgfPrQPrVekU+bCX9hL5Yg=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=Y9H0KNc9UFMdEGWssW/x80JhX39YZmZbEV4rDvNa8X0FdItoqTaVj9YDglWXV7iXNwd4PuyeruJ4PSWHkJpJ3yhVnx7qRQznJq5Xjzz+v4FLLRzmj8y9umo54Oo9ShBZRsmhxkF5hNXC/FYvotdeUGAXAfgUWUWk5zaL1sTNUD0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=UD51IBLU; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="UD51IBLU" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 63472C116B1; Fri, 26 Jul 2024 01:37:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1721957827; bh=HZeRnqI2Oykvkscalx44mKgfPrQPrVekU+bCX9hL5Yg=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=UD51IBLUgUSi0SlQd/gd/7JvswvEUkyslNSavzcnwdIlTPt9k7M0HDTIsspVELRaB vJG381hwGDTTyKfONhK3Zi7dOnlPeEF1wwIUJ3SvCDU2qGs9tr5n+rlQ+kV4h4c2sE MBjJmW3HjSdzmNlaClWjP0SXCxZXEMC/7LWYnkVrnspIf7M8xodhEpSMvDFBhnmVyE jj+DNuJqW8DVaCc3L5AE4qavu2puk3F4VzkuZeJPTEljqtOv0cpETGr3/C6+K8mZLX ym3B44YNps1BEwEwVWi8rMJ1JbJMPVEBGoPBOL8wUdGZd9MgzOkDVUHxFyzkEPuuVi fD456o8XEOKwg== Date: Thu, 25 Jul 2024 18:37:05 -0700 From: Namhyung Kim To: =?utf-8?B?5ZC06Zuo6JaH?= Cc: linux-perf-users@vger.kernel.org, =?utf-8?B?5LqO5L2z6ICV6ICB5biI?= , shenzhengdong23@mails.ucas.ac.cn Subject: Re: Kernel functions showing only addresses in `perf` output Message-ID: References: <4928374a.92fe.190e4705e87.Coremail.wuyuwei221@mails.ucas.ac.cn> Precedence: bulk X-Mailing-List: linux-perf-users@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <4928374a.92fe.190e4705e87.Coremail.wuyuwei221@mails.ucas.ac.cn> Hello, On Wed, Jul 24, 2024 at 07:11:27PM +0800, 吴雨薇 wrote: > Kernel functions are only showing addresses and not symbols in the sampling output from the `perf` tool. > > Environment Information > - Hardware: SG2042 > - OS Version: openEuler 23.09 > - Kernel Version: Linux openeuler-riscv64 6.6.0+ #1 SMP Wed Apr 3 15:53:06 CST 2024 riscv64 riscv64 riscv64 GNU/Linux > - Perf Version: 6.6.g04f0a6491967 > - Kernel Compilation Options: > The following kernel configuration options have been enabled: > CONFIG_PERF_EVENTS > CONFIG_KALLSYMS > CONFIG_KALLSYMS_ALL > CONFIG_FRAME_POINTER > CONFIG_STACKTRACE > CONFIG_DEBUG_INFO > > CONFIG_DEBUG_KERNEL > > > > Steps to Reproduce > > 1. Download Kernel Source Code: > Clone the kernel source code repository on the Lichee Pi 4A board > > 2. Install Dependencies: > Install all necessary development libraries and tools required by `perf`: > sudo yum install elfutils-libelf-devel -y > sudo yum install perl-devel -y > sudo yum install numactl-devel -y > sudo yum install libbabeltrace-devel -y > sudo yum install binutils-devel -y > sudo yum install genwqe-zlib-static -y > sudo yum install elfutils-devel -y > sudo yum install slang-devel -y > sudo yum install zstd-devel -y > sudo yum install xz-devel -y > sudo yum install libcap-devel -y > sudo yum install audit-devel audit-libs -y > sudo yum install openssl-devel -y > sudo yum install gtk2-devel -y > sudo yum install systemtap-sdt-devel -y > sudo yum install libtraceevent-devel -y > sudo yum install libpfm -y > sudo yum install ncurses-devel -y > sudo yum install java-1.8.0-openjdk-devel -y > > 3. Compile `perf`: > cd riscv-kernel/tools/perf > make ARCH=riscv WERROR=0 -j4 > > 4. Install `perf`: > sudo cp ./perf /usr/bin/ > > 5. Download `hackbench` > > 6. Compile `hackbench`: > gcc -static -O0 -g -fno-omit-frame-pointer hackbench.c -o hackbench -lpthread > > 7. Run Tests with `perf`: > Record performance data with `perf` and generate the report: > sudo perf record -e cpu-cycles -g ./hackbench > sudo perf report --no-children -G > perf_hackbench.txt > > > Issue > In the `perf_hackbench.txt` output, you can see that kernel functions show addresses, while user mode functions show function symbol names > 96.22% hackbench [unknown] [k] 0xffffffff80cfb2ac > > Potential Cause： > It seems that `perf` might be failing to resolve addresses to symbols because it cannot find the addresses in `/proc/kallsyms`. Can you please run `perf script --show-mmap-events` ? I'd like to see if it has proper mappings in the data file. Thanks, Namhyung