From nobody Thu Jan 1 08:57:43 2026 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 1C7BCC25B47 for ; Tue, 24 Oct 2023 22:25:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1344583AbjJXWZ0 (ORCPT ); Tue, 24 Oct 2023 18:25:26 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59894 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1344558AbjJXWZG (ORCPT ); Tue, 24 Oct 2023 18:25:06 -0400 Received: from mail-yw1-x1149.google.com (mail-yw1-x1149.google.com [IPv6:2607:f8b0:4864:20::1149]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 46CB510D1 for ; Tue, 24 Oct 2023 15:24:41 -0700 (PDT) Received: by mail-yw1-x1149.google.com with SMTP id 00721157ae682-5a839b31a0dso94314447b3.0 for ; Tue, 24 Oct 2023 15:24:41 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1698186280; x=1698791080; darn=vger.kernel.org; h=to:from:subject:references:mime-version:message-id:in-reply-to:date :from:to:cc:subject:date:message-id:reply-to; bh=m3RrFaAylSJfbHKcTDzvj4sdZE51LV5H16MsLijA4K8=; b=UEQxx/EE0WtiG9dMIp4bJpg1YKY88bG+AufaRZWd9HFwxpHH5JY2Fl1U16waQAeGEO uRa+PYvkIDGXPxN6K6ecLrp2PIQem4YVBdIEinc0kRyfAHOMkclMGXkJsCKfq+8wz9no of0a/G3PxbIgUTFZ1Zgy2ERPtV83GcjlyIHcDmnccPogIiVL//y7hufQC85+tfkZyX++ 8yt+S72qyrnHrWRwu23IlpgX2Rtjo4bq4H4vi5gjVvJWTJItoe4xo9T3DGF+vkJ1Qyei lw020vG7K2N3so94j/txWSbAWkF/3fHzhCxH9grblZsqpZiw/bjb0KIsai0xuxHOUs4E MG6A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1698186280; x=1698791080; h=to:from:subject:references:mime-version:message-id:in-reply-to:date :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=m3RrFaAylSJfbHKcTDzvj4sdZE51LV5H16MsLijA4K8=; b=pwmEFzHCY1hvr9iWWDGOeU4MrgWt2ucqv6jwBE/1xHmgyZTwYrTFuW+hznB0k/TYuh Fq9RxEwky2/pGbTUNP5BiHYc7BtOzJ9qAai2aGf6vudP4Tn3gNuryhnTr4RmTFVH7+2q r4SDT9pjE+OtRv5tFkZkxJOEJigrgnPgnmFIYwhuivVIZU2yRjRJQnmBQp1zJu/RKk9T VwN66A3pUQvDbmJBhByJ9H82RBNBH/0QewTwLLhtoQpkW5dhUWUAWmXwyIkSQBaHDW9+ MtyQNOaDh0qr3aomodF9oTSYAMsX2igV5Cnqfx6g2zuBYXL7Mc8elyeZSviYgyRQBDwx vLNw== X-Gm-Message-State: AOJu0YzwIJIU5DmWdu3m6SgrE1gUIOlyw/2KnT1CtouB5jO3HiV/uE1j xBco5SuELiURBF/7tO2c+vVb6hDhuDml X-Google-Smtp-Source: AGHT+IG7PiEiZBvMWRGIx6ray9LXHq/rj6CT4JZEt1Y0UxVGlAZHKrDrvwGEiXycViuLesPoNC5gYWcPDgX+ X-Received: from irogers.svl.corp.google.com ([2620:15c:2a3:200:93d2:18cc:4d63:45ba]) (user=irogers job=sendgmr) by 2002:a81:5206:0:b0:5a7:b672:4d88 with SMTP id g6-20020a815206000000b005a7b6724d88mr288070ywb.0.1698186279736; Tue, 24 Oct 2023 15:24:39 -0700 (PDT) Date: Tue, 24 Oct 2023 15:23:15 -0700 In-Reply-To: <20231024222353.3024098-1-irogers@google.com> Message-Id: <20231024222353.3024098-13-irogers@google.com> Mime-Version: 1.0 References: <20231024222353.3024098-1-irogers@google.com> X-Mailer: git-send-email 2.42.0.758.gaed0368e0e-goog Subject: [PATCH v3 12/50] perf record: Lazy load kernel symbols From: Ian Rogers To: Peter Zijlstra , Ingo Molnar , Arnaldo Carvalho de Melo , Mark Rutland , Alexander Shishkin , Jiri Olsa , Namhyung Kim , Ian Rogers , Adrian Hunter , Nick Terrell , Kan Liang , Andi Kleen , Leo Yan , Song Liu , Sandipan Das , James Clark , Anshuman Khandual , Miguel Ojeda , Liam Howlett , Yang Jihong , Athira Rajeev , Kajol Jain , K Prateek Nayak , Sean Christopherson , Yanteng Si , Ravi Bangoria , German Gomez , Changbin Du , Paolo Bonzini , Masami Hiramatsu , liuwenyu , linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Commit 5b7ba82a7591 ("perf symbols: Load kernel maps before using") changed it so that loading a kernel dso would cause the symbols for the dso to be eagerly loaded. For perf record this is overhead as the symbols won't be used. Add a symbol_conf to control the behavior and disable it for perf record and perf inject. Signed-off-by: Ian Rogers --- tools/perf/builtin-inject.c | 6 ++++++ tools/perf/builtin-record.c | 2 ++ tools/perf/util/event.c | 4 ++-- tools/perf/util/symbol_conf.h | 3 ++- 4 files changed, 12 insertions(+), 3 deletions(-) diff --git a/tools/perf/builtin-inject.c b/tools/perf/builtin-inject.c index c8cf2fdd9cff..eb3ef5c24b66 100644 --- a/tools/perf/builtin-inject.c +++ b/tools/perf/builtin-inject.c @@ -2265,6 +2265,12 @@ int cmd_inject(int argc, const char **argv) "perf inject []", NULL }; + + if (!inject.itrace_synth_opts.set) { + /* Disable eager loading of kernel symbols that adds overhead to perf in= ject. */ + symbol_conf.lazy_load_kernel_maps =3D true; + } + #ifndef HAVE_JITDUMP set_option_nobuild(options, 'j', "jit", "NO_LIBELF=3D1", true); #endif diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c index dcf288a4fb9a..8ec818568662 100644 --- a/tools/perf/builtin-record.c +++ b/tools/perf/builtin-record.c @@ -3989,6 +3989,8 @@ int cmd_record(int argc, const char **argv) # undef set_nobuild #endif =20 + /* Disable eager loading of kernel symbols that adds overhead to perf rec= ord. */ + symbol_conf.lazy_load_kernel_maps =3D true; rec->opts.affinity =3D PERF_AFFINITY_SYS; =20 rec->evlist =3D evlist__new(); diff --git a/tools/perf/util/event.c b/tools/perf/util/event.c index 923c0fb15122..68f45e9e63b6 100644 --- a/tools/perf/util/event.c +++ b/tools/perf/util/event.c @@ -617,13 +617,13 @@ struct map *thread__find_map(struct thread *thread, u= 8 cpumode, u64 addr, if (cpumode =3D=3D PERF_RECORD_MISC_KERNEL && perf_host) { al->level =3D 'k'; maps =3D machine__kernel_maps(machine); - load_map =3D true; + load_map =3D !symbol_conf.lazy_load_kernel_maps; } else if (cpumode =3D=3D PERF_RECORD_MISC_USER && perf_host) { al->level =3D '.'; } else if (cpumode =3D=3D PERF_RECORD_MISC_GUEST_KERNEL && perf_guest) { al->level =3D 'g'; maps =3D machine__kernel_maps(machine); - load_map =3D true; + load_map =3D !symbol_conf.lazy_load_kernel_maps; } else if (cpumode =3D=3D PERF_RECORD_MISC_GUEST_USER && perf_guest) { al->level =3D 'u'; } else { diff --git a/tools/perf/util/symbol_conf.h b/tools/perf/util/symbol_conf.h index 0b589570d1d0..2b2fb9e224b0 100644 --- a/tools/perf/util/symbol_conf.h +++ b/tools/perf/util/symbol_conf.h @@ -42,7 +42,8 @@ struct symbol_conf { inline_name, disable_add2line_warn, buildid_mmap2, - guest_code; + guest_code, + lazy_load_kernel_maps; const char *vmlinux_name, *kallsyms_name, *source_prefix, --=20 2.42.0.758.gaed0368e0e-goog