From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from szxga03-in.huawei.com (szxga03-in.huawei.com [45.249.212.189]) (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 63CCB4690 for ; Thu, 25 Jul 2024 02:16:17 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=45.249.212.189 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1721873780; cv=none; b=JOw2u0HfO0POdz1xrTVdHNdYfIkfA4tqXNT9esX+9hBi0gqyXH7v+239ljdzy0W8SJzN8/nSfTmtUASA5g7H8j6TR5n7k1JN/Ge5ulkum8yZ+OZXvOUV5Ln6gmgvKP96e1pP4iS8jNObOjDte9P7hKQvaV3qBhsFfePaTS5YGI4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1721873780; c=relaxed/simple; bh=XuaIdgysxkYXF0pfGRwT213/rDERO44AiZG9z99Ilns=; h=From:To:CC:Subject:Date:Message-ID:MIME-Version:Content-Type; b=doDm24udalxtGIzOgR6UWCm6KHwyKHEsSzU1qnaTQxrdN5QrEtmLuNct68TbKh8c+IF3qjY8iQdBRN+GjxuRtgRVCveKbDOlxYiM+wvK6rchE4bBz5PW/ELQFcSABoElRqzj6lUges+2LBteezJJIsysVpMUmc6RhW1dE/eVs/s= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com; spf=pass smtp.mailfrom=huawei.com; arc=none smtp.client-ip=45.249.212.189 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=huawei.com Received: from mail.maildlp.com (unknown [172.19.162.254]) by szxga03-in.huawei.com (SkyGuard) with ESMTP id 4WTvXL2s9pzQn5C; Thu, 25 Jul 2024 10:12:02 +0800 (CST) Received: from kwepemd100011.china.huawei.com (unknown [7.221.188.204]) by mail.maildlp.com (Postfix) with ESMTPS id 4E97A180102; Thu, 25 Jul 2024 10:16:14 +0800 (CST) Received: from M910t.huawei.com (10.110.54.157) by kwepemd100011.china.huawei.com (7.221.188.204) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1258.34; Thu, 25 Jul 2024 10:16:12 +0800 From: Changbin Du To: Peter Zijlstra , Ingo Molnar , Arnaldo Carvalho de Melo , Namhyung Kim , Nathan Chancellor CC: Mark Rutland , Alexander Shishkin , Jiri Olsa , Ian Rogers , Adrian Hunter , "Liang, Kan" , Nick Desaulniers , Bill Wendling , Justin Stitt , , , , Hui Wang , Changbin Du Subject: [PATCH v6 0/8] perf: Support searching local debugging vdso or specify vdso path in cmdline Date: Thu, 25 Jul 2024 10:15:41 +0800 Message-ID: <20240725021549.880167-1-changbin.du@huawei.com> X-Mailer: git-send-email 2.34.1 Precedence: bulk X-Mailing-List: llvm@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8bit X-ClientProxiedBy: dggems706-chm.china.huawei.com (10.3.19.183) To kwepemd100011.china.huawei.com (7.221.188.204) The vdso dumped from process memory (in buildid-cache) lacks debugging info. To annotate vdso symbols with source lines we need a debugging version. For x86, we can find them from your local build as 'arch/x86/entry/vdso/vdso{32,64}.so.dbg'. Or they may resides in '/lib/modules//vdso/vdso{32,64}.so' on Ubuntu. But notice that the builid has to match. If user doesn't specify the path, perf will search them internally as long as vmlinux when recording samples. The searched debugging vdso will add to buildid cache. Below samples are captured on my local build kernel. perf succesfully find debugging version vdso and we can annotate with source without specifying vdso path. $ sudo perf record -a $ sudo perf report --objdump=llvm-objdump Samples: 17K of event 'cycles:P', 4000 Hz, Event count (approx.): 1760 __vdso_clock_gettime /work/linux-host/arch/x86/entry/vdso/vdso64.so.d Percent│ movq -48(%rbp),%rsi │ testq %rax,%rax │ ; return vread_hvclock(); │ movq %rax,%rdx │ ; if (unlikely(!vdso_cycles_ok(cycles))) │ ↑ js eb │ ↑ jmp 74 │ ; ts->tv_sec = vdso_ts->sec; 0.02 │147: leaq 2(%rbx),%rax │ shlq $4, %rax │ addq %r10,%rax │ ; while ((seq = READ_ONCE(vd->seq)) & 1) { 9.38 │152: movl (%r10),%ecx When doing cross platform analysis, we need to specify the vdso path if we are interested in its symbols. At most two vdso can be given. Also you can pack your buildid cache with perf-archive if the debugging vdso can be found on the sampled machine. $ sudo perf report --objdump=llvm-objdump \ --vdso arch/x86/entry/vdso/vdso64.so.dbg,arch/x86/entry/vdso/vdso32.so.dbg I also improved perf-buildid-cache command recognize vdso when adding files, then place it at correct place. v6: - split "perf: build-id: try to search debugging vdso and add to cache" by functional logical. (suggested by Adrian) v5: - Searching the vdso in record stage instead of report. So the debugging vdso will be in build-id cache. This is friendly for cross-machine analysis. - Improve perf-buildid-cache command recognize vdso when adding files v4: - split the refactoring from the actual change. v3: - update documentation. v2: - now search vdso automatically as long as vmlinux, as suggested by Adrian. - remove change 'prefer symsrc_filename for filename'. Changbin Du (8): perf: support specify vdso path in cmdline perf: disasm: refactor function dso__disassemble_filename perf: disasm: use build_id_path if fallback failed perf: symbol: generalize vmlinux path searching perf: build-id: add support for build-id cache vdso debug perf: build-id: extend build_id_cache__find_debug() to find local debugging vdso perf: disasm: prefer debugging files in build-id cache perf buildid-cache: recognize vdso when adding files tools/perf/Documentation/perf-annotate.txt | 3 + tools/perf/Documentation/perf-c2c.txt | 3 + tools/perf/Documentation/perf-inject.txt | 3 + tools/perf/Documentation/perf-report.txt | 3 + tools/perf/Documentation/perf-script.txt | 3 + tools/perf/Documentation/perf-top.txt | 3 + tools/perf/builtin-annotate.c | 2 + tools/perf/builtin-buildid-cache.c | 26 ++- tools/perf/builtin-c2c.c | 2 + tools/perf/builtin-inject.c | 2 + tools/perf/builtin-report.c | 2 + tools/perf/builtin-script.c | 2 + tools/perf/builtin-top.c | 2 + tools/perf/util/build-id.c | 57 +++++- tools/perf/util/disasm.c | 131 ++++++++----- tools/perf/util/machine.c | 4 +- tools/perf/util/symbol.c | 209 ++++++++++++++++----- tools/perf/util/symbol.h | 9 +- tools/perf/util/symbol_conf.h | 5 + 19 files changed, 359 insertions(+), 112 deletions(-) -- 2.34.1