From nobody Sun Sep 22 05:38:58 2024 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 9EF58C433F5 for ; Tue, 26 Apr 2022 12:24:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239701AbiDZM1j (ORCPT ); Tue, 26 Apr 2022 08:27:39 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51412 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234339AbiDZM1f (ORCPT ); Tue, 26 Apr 2022 08:27:35 -0400 Received: from mailgw02.mediatek.com (unknown [210.61.82.184]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 75F8015AE0E for ; Tue, 26 Apr 2022 05:24:27 -0700 (PDT) X-UUID: 04aee38b8ee7468ba8aba8e641dbf88e-20220426 X-CID-P-RULE: Release_Ham X-CID-O-INFO: VERSION:1.1.4,REQID:b1772e2a-f2b1-483c-8415-f0fdec7e7836,OB:0,LO B:0,IP:0,URL:0,TC:0,Content:-20,EDM:0,RT:0,SF:0,FILE:0,RULE:Release_Ham,AC TION:release,TS:-20 X-CID-META: VersionHash:faefae9,CLOUDID:9781c22e-6199-437e-8ab4-9920b4bc5b76,C OID:IGNORED,Recheck:0,SF:nil,TC:nil,Content:0,EDM:-3,File:nil,QS:0,BEC:nil X-UUID: 04aee38b8ee7468ba8aba8e641dbf88e-20220426 Received: from mtkexhb01.mediatek.inc [(172.21.101.102)] by mailgw02.mediatek.com (envelope-from ) (Generic MTA with TLSv1.2 ECDHE-RSA-AES256-SHA384 256/256) with ESMTP id 1964950952; Tue, 26 Apr 2022 20:24:21 +0800 Received: from mtkexhb02.mediatek.inc (172.21.101.103) by mtkmbs10n2.mediatek.inc (172.21.101.183) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384) id 15.2.792.3; Tue, 26 Apr 2022 20:24:20 +0800 Received: from mtkcas10.mediatek.inc (172.21.101.39) by mtkexhb02.mediatek.inc (172.21.101.103) with Microsoft SMTP Server (TLS) id 15.0.1497.2; Tue, 26 Apr 2022 20:24:19 +0800 Received: from mtksdccf07.mediatek.inc (172.21.84.99) by mtkcas10.mediatek.inc (172.21.101.73) with Microsoft SMTP Server id 15.0.1497.2 via Frontend Transport; Tue, 26 Apr 2022 20:24:19 +0800 From: Mark-PK Tsai To: CC: , , , , , , Subject: [PATCH v4 2/2] tracing: make tracer_init_tracefs initcall asynchronous Date: Tue, 26 Apr 2022 20:24:07 +0800 Message-ID: <20220426122407.17042-3-mark-pk.tsai@mediatek.com> X-Mailer: git-send-email 2.18.0 In-Reply-To: <20220426122407.17042-1-mark-pk.tsai@mediatek.com> References: <20220426122407.17042-1-mark-pk.tsai@mediatek.com> MIME-Version: 1.0 X-MTK: N Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Move trace_eval_init() to subsys_initcall to make it start earlier. And to avoid tracer_init_tracefs being blocked by trace_event_sem which trace_eval_init() hold [1], queue tracer_init_tracefs() to eval_map_wq to let the two works being executed sequentially. It can speed up the initialization of kernel as result of making tracer_init_tracefs asynchronous. On my arm64 platform, it reduce ~20ms of 125ms which total time do_initcalls spend. [1]: https://lore.kernel.org/r/68d7b3327052757d0cd6359a6c9015a85b437232.cam= el@pengutronix.de Signed-off-by: Mark-PK Tsai --- kernel/trace/trace.c | 32 ++++++++++++++++++++++---------- 1 file changed, 22 insertions(+), 10 deletions(-) diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 0ec7b013104a..7f6ad8f06129 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -9615,6 +9615,7 @@ extern struct trace_eval_map *__stop_ftrace_eval_maps= []; =20 static struct workqueue_struct *eval_map_wq __initdata; static struct work_struct eval_map_work __initdata; +static struct work_struct tracerfs_init_work __initdata; =20 static void __init eval_map_work_func(struct work_struct *work) { @@ -9640,6 +9641,8 @@ static int __init trace_eval_init(void) return 0; } =20 +subsys_initcall(trace_eval_init); + static int __init trace_eval_sync(void) { /* Make sure the eval map updates are finished */ @@ -9722,15 +9725,8 @@ static struct notifier_block trace_module_nb =3D { }; #endif /* CONFIG_MODULES */ =20 -static __init int tracer_init_tracefs(void) +static __init void tracer_init_tracefs_work_func(struct work_struct *work) { - int ret; - - trace_access_lock_init(); - - ret =3D tracing_init_dentry(); - if (ret) - return 0; =20 event_trace_init(); =20 @@ -9752,8 +9748,6 @@ static __init int tracer_init_tracefs(void) trace_create_file("saved_tgids", TRACE_MODE_READ, NULL, NULL, &tracing_saved_tgids_fops); =20 - trace_eval_init(); - trace_create_eval_file(NULL); =20 #ifdef CONFIG_MODULES @@ -9768,6 +9762,24 @@ static __init int tracer_init_tracefs(void) create_trace_instances(NULL); =20 update_tracer_options(&global_trace); +} + +static __init int tracer_init_tracefs(void) +{ + int ret; + + trace_access_lock_init(); + + ret =3D tracing_init_dentry(); + if (ret) + return 0; + + if (eval_map_wq) { + INIT_WORK(&tracerfs_init_work, tracer_init_tracefs_work_func); + queue_work(eval_map_wq, &tracerfs_init_work); + } else { + tracer_init_tracefs_work_func(NULL); + } =20 return 0; } --=20 2.18.0