From patchwork Wed Mar 16 15:16:39 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: =?utf-8?b?TWFyay1QSyBUc2FpICjolKHmspvliZsp?= X-Patchwork-Id: 12782883 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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id D9EF8C433EF for ; Wed, 16 Mar 2022 15:30:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:Message-ID:Date:Subject:CC :To:From:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To:References: List-Owner; bh=rkgsiKt8VRKYOCxJ66TWwYLkraJ6LrY+M6O42oqnnPA=; b=PVrdLsGRoPkQ3M 1liBZASTS6CLT9BUHqh5PPHShc8vRzLHJR9vEGg5UFOK+Hx3h2GEzPoEmArhu5dM9vXAXMEiQx5SV VkyN9hygiI1RtkqP7kLOM4D8n0No7MscKXgC1f9LxHAlVS9dEqzEAiFuLxlP7MENPo+nKX3aibsXx 1X5vbgJg2QdqnTEhHzyr+bc5b0MwQQPAqHFQZxugjGK9TpLyWIT82Hw9TB2t2sQ7adjvY2pDMA0Qn vCeK1yi3Ji0V4ThX0i55ubvyb4dWvfds4UlwuwTdvrcYI/eqF7JjhMgMOVSeex1o1VjX4ovwc8Ant LiAyVj7U8hEEWecl4KNg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1nUVad-00DYgo-0Q; Wed, 16 Mar 2022 15:29:31 +0000 Received: from mailgw01.mediatek.com ([216.200.240.184]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1nUVQL-00DUIX-FF; Wed, 16 Mar 2022 15:18:56 +0000 X-UUID: 14b32c146a6944c9b784dc4f20b62532-20220316 X-UUID: 14b32c146a6944c9b784dc4f20b62532-20220316 Received: from mtkcas66.mediatek.inc [(172.29.193.44)] by mailgw01.mediatek.com (envelope-from ) (musrelay.mediatek.com ESMTP with TLSv1.2 ECDHE-RSA-AES256-SHA384 256/256) with ESMTP id 1801798110; Wed, 16 Mar 2022 08:18:49 -0700 Received: from mtkmbs10n1.mediatek.inc (172.21.101.34) by MTKMBS62DR.mediatek.inc (172.29.94.18) with Microsoft SMTP Server (TLS) id 15.0.1497.2; Wed, 16 Mar 2022 08:16:42 -0700 Received: from mtkcas11.mediatek.inc (172.21.101.40) by mtkmbs10n1.mediatek.inc (172.21.101.34) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384) id 15.2.792.15; Wed, 16 Mar 2022 23:16:41 +0800 Received: from mtksdccf07.mediatek.inc (172.21.84.99) by mtkcas11.mediatek.inc (172.21.101.73) with Microsoft SMTP Server id 15.0.1497.2 via Frontend Transport; Wed, 16 Mar 2022 23:16:41 +0800 From: Mark-PK Tsai To: , CC: , , , , , Subject: [PATCH v2] tracing: make tracer_init_tracefs initcall asynchronous Date: Wed, 16 Mar 2022 23:16:39 +0800 Message-ID: <20220316151639.9216-1-mark-pk.tsai@mediatek.com> X-Mailer: git-send-email 2.18.0 MIME-Version: 1.0 X-MTK: N X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220316_081853_570196_2FAF438F X-CRM114-Status: GOOD ( 15.17 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org 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.camel@pengutronix.de Signed-off-by: Mark-PK Tsai --- kernel/trace/trace.c | 31 +++++++++++++++++++++---------- 1 file changed, 21 insertions(+), 10 deletions(-) diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index eb44418574f9..adb37e437a05 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -9564,6 +9564,7 @@ extern struct trace_eval_map *__stop_ftrace_eval_maps[]; static struct workqueue_struct *eval_map_wq __initdata; static struct work_struct eval_map_work __initdata; +static struct work_struct tracerfs_init_work __initdata; static void __init eval_map_work_func(struct work_struct *work) { @@ -9589,6 +9590,8 @@ static int __init trace_eval_init(void) return 0; } +subsys_initcall(trace_eval_init); + static int __init trace_eval_sync(void) { /* Make sure the eval map updates are finished */ @@ -9671,15 +9674,8 @@ static struct notifier_block trace_module_nb = { }; #endif /* CONFIG_MODULES */ -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 = tracing_init_dentry(); - if (ret) - return 0; event_trace_init(); @@ -9701,8 +9697,6 @@ static __init int tracer_init_tracefs(void) trace_create_file("saved_tgids", TRACE_MODE_READ, NULL, NULL, &tracing_saved_tgids_fops); - trace_eval_init(); - trace_create_eval_file(NULL); #ifdef CONFIG_MODULES @@ -9717,6 +9711,23 @@ static __init int tracer_init_tracefs(void) create_trace_instances(NULL); update_tracer_options(&global_trace); +} + +static __init int tracer_init_tracefs(void) +{ + int ret; + + trace_access_lock_init(); + + ret = tracing_init_dentry(); + if (ret) + return 0; + + INIT_WORK(&tracerfs_init_work, tracer_init_tracefs_work_func); + if (!eval_map_wq) + tracer_init_tracefs_work_func(&tracerfs_init_work); + else + queue_work(eval_map_wq, &tracerfs_init_work); return 0; }