From nobody Fri Dec 19 04:02:16 2025 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 7F2D0CDB46E for ; Thu, 12 Oct 2023 06:25:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1377655AbjJLGZH (ORCPT ); Thu, 12 Oct 2023 02:25:07 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50780 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1377453AbjJLGYs (ORCPT ); Thu, 12 Oct 2023 02:24:48 -0400 Received: from mail-yw1-x114a.google.com (mail-yw1-x114a.google.com [IPv6:2607:f8b0:4864:20::114a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1FF781A3 for ; Wed, 11 Oct 2023 23:24:31 -0700 (PDT) Received: by mail-yw1-x114a.google.com with SMTP id 00721157ae682-5a7a6fd18abso9897927b3.1 for ; Wed, 11 Oct 2023 23:24:31 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1697091870; x=1697696670; 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=Fc/6/O/gRte1zMhmeMtD4ohISB3aWdPXWc8V2/IjDG4=; b=MfjQ5C7JEOErhS+sVyt+9BIu5x/F+EcfbqxY16YvfH+Baa1uydnkaaaYfeNb++GAhe w1jyj9CRpk9NtQvcuVy0u8EgsYvvICa06QNJGL60h6i1fNgf6a6eec6bbWSHgn9MylgN ctHoEn3sNsfj17CE9duwG0Bt25OAZbgB5aOLWOMaeZIxRP1wm1cyCvbm4lnSbrqK6J7T FjjHz3WCelmLYsstXYwiICf40c9lSzvWP+JzzaATTDQuiHLMs8ZhSdTHGTz5Fk3VVVEV labXbkeucDueh9576aAAymNQDILXk4SL3yfSOXvYg7Wk8wqWmtjhHPUjLgpuc1NODLkv KcfA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1697091870; x=1697696670; 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=Fc/6/O/gRte1zMhmeMtD4ohISB3aWdPXWc8V2/IjDG4=; b=JeQ8y4sZW8FhFE2q/ErWDBeUHvDF6MnMviuK7oLWPxqo6e5aYq7wjPI2DeuZhldHrS 0UBlk/ziFCByar0zZ6lSXJQk8hG84qpAbhHLpCZtqIsjRNWS2lJB1e3rK05CkqD15XAm nRNVc+2E2ijV+mMOUzaV9w8i33QWBco4F0SROJpNhcZdv07/NWRb/b01c51bqF/YIiBj dviotIwI/9WBDfLFENNewQH6HM8bU3C+MCkJu5zbRU7tZ18ReI2bIK/y5PBc3PbhXmp2 JSwDeuu3atZ9JmRsdT4Myz3TfSwpG7busHsat96iwmqngpQ+chwyqX8BzvotCf81RHG4 UT9Q== X-Gm-Message-State: AOJu0YwBALAdaDRGAzeps3Wzy0iwVjucWAk15wiVVWBNfxl/zW2rai20 rBHzX4ioN3eOygg/JNwQQvw6w/KLiBvx X-Google-Smtp-Source: AGHT+IHw9CWAC8FY76ZB7h38HkJJCF9yox3JXqj1NldAlfSd6AeHsF169JHHn8w35OGyvCUjrw3Xt+ij0Xpl X-Received: from irogers.svl.corp.google.com ([2620:15c:2a3:200:7be5:14d2:880b:c5c9]) (user=irogers job=sendgmr) by 2002:a81:4005:0:b0:5a7:be34:345 with SMTP id l5-20020a814005000000b005a7be340345mr175704ywn.6.1697091870082; Wed, 11 Oct 2023 23:24:30 -0700 (PDT) Date: Wed, 11 Oct 2023 23:23:56 -0700 In-Reply-To: <20231012062359.1616786-1-irogers@google.com> Message-Id: <20231012062359.1616786-11-irogers@google.com> Mime-Version: 1.0 References: <20231012062359.1616786-1-irogers@google.com> X-Mailer: git-send-email 2.42.0.609.gbb76f46606-goog Subject: [PATCH v2 10/13] 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 , Song Liu , Sandipan Das , Anshuman Khandual , James Clark , Liam Howlett , Miguel Ojeda , Leo Yan , German Gomez , Ravi Bangoria , Artem Savkov , Athira Rajeev , Andi Kleen , linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org, bpf@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 | 4 ++++ tools/perf/builtin-record.c | 2 ++ tools/perf/util/event.c | 4 ++-- tools/perf/util/symbol_conf.h | 3 ++- 4 files changed, 10 insertions(+), 3 deletions(-) diff --git a/tools/perf/builtin-inject.c b/tools/perf/builtin-inject.c index c8cf2fdd9cff..1539fb18c749 100644 --- a/tools/perf/builtin-inject.c +++ b/tools/perf/builtin-inject.c @@ -2265,6 +2265,10 @@ int cmd_inject(int argc, const char **argv) "perf inject []", NULL }; + + /* Disable eager loading of kernel symbols that adds overhead to perf inj= ect. */ + 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 2.42.0.609.gbb76f46606-goog