From patchwork Wed Mar 23 15:22:57 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: 12789835 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 C819BC433F5 for ; Wed, 23 Mar 2022 15:24:41 +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:References:In-Reply-To: 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: List-Owner; bh=5A990W52Je2MCr+CZW3i65NAZaomqCjrflb7nf3J9WM=; b=WuI8fj5+E5D7Jm 0LMtiR5nk81E3KknFuxnxliZxwFIlxW/G1IBedgEZ6VR3UCgQY3o9hClnDpXiYSFg3s8v7ArdWoO6 mOKJRHNUgiMBGgxbegxFgO3OocekPLumbHH0k3MsCtqZw0sL/ijW561eqbRe/HXi3nBE8Jn9F0c44 KtkTBkdVEKb13YTKSgTlNU+3GenhSUHtzViaOq8KmfI5Q/YEzsVLGLsRcv5QLXZipJHJIBZFOrUqO F0ocFrnjynIufcjvjNoEb+bQZzqryWyWT0GQUqnpaq4kLgU33Op0Zdf1X9Zo2X2z4FniGcpIImHsP cHoRubRZQVgO6xAZuF5g==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1nX2pX-00E4m5-6E; Wed, 23 Mar 2022 15:23:24 +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 1nX2pO-00E4jW-6Y; Wed, 23 Mar 2022 15:23:15 +0000 X-UUID: 8d0e4e6fbe9b42aca6bca4af67bc5772-20220323 X-UUID: 8d0e4e6fbe9b42aca6bca4af67bc5772-20220323 Received: from mtkcas68.mediatek.inc [(172.29.94.19)] by mailgw01.mediatek.com (envelope-from ) (musrelay.mediatek.com ESMTP with TLSv1.2 ECDHE-RSA-AES256-SHA384 256/256) with ESMTP id 666822239; Wed, 23 Mar 2022 08:23:06 -0700 Received: from mtkmbs10n2.mediatek.inc (172.21.101.183) by MTKMBS62N1.mediatek.inc (172.29.193.41) with Microsoft SMTP Server (TLS) id 15.0.1497.2; Wed, 23 Mar 2022 08:23:04 -0700 Received: from mtkcas10.mediatek.inc (172.21.101.39) 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; Wed, 23 Mar 2022 23:23:03 +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; Wed, 23 Mar 2022 23:23:02 +0800 From: Mark-PK Tsai To: , CC: , , , , , Subject: [PATCH v3 2/2] tracing: make tracer_init_tracefs initcall asynchronous Date: Wed, 23 Mar 2022 23:22:57 +0800 Message-ID: <20220323152257.7871-3-mark-pk.tsai@mediatek.com> X-Mailer: git-send-email 2.18.0 In-Reply-To: <20220323152257.7871-1-mark-pk.tsai@mediatek.com> References: <20220323152257.7871-1-mark-pk.tsai@mediatek.com> MIME-Version: 1.0 X-MTK: N X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220323_082314_291012_FB59BF47 X-CRM114-Status: GOOD ( 15.55 ) 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 85ec758c4455..2974ae056068 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -9571,6 +9571,7 @@ 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) { @@ -9596,6 +9597,8 @@ 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 */ @@ -9678,15 +9681,8 @@ 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(); @@ -9708,8 +9704,6 @@ 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 @@ -9724,6 +9718,23 @@ 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; }