From nobody Mon Feb 9 14:24:24 2026 Received: from mailgw.kylinos.cn (mailgw.kylinos.cn [124.126.103.232]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 6A85E20E03F; Wed, 28 Jan 2026 12:54:18 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=124.126.103.232 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769604862; cv=none; b=k1gaGrbk428uL42Z89NEWw7L0/VqbrsZxyWMAVCN54c8QPtlsEg1zd8qVIBh7obsj2T7z82qY5blHx1pEnu2TI6yteUo/jwHh6juw/HWdc+MPlAUNfO/xtqMRdzYMmJSRoT6OMGYHoRdLDpw8Shsatn7dGKsx9ezVvxFmMarqSc= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769604862; c=relaxed/simple; bh=gb8+RLwH1mLnHCvquqykDWLMdPea4d3L/yrMxNd7l2g=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=lqVBGV9NxbnSsYnP6nFs65BH06erfKWNV12JIknbVWMrjjOltTUHdxcsYMrn021DWigsKDeZsrW49PLnIkB5iXrY2wCqzD4H02Drnw1NciDRYzWWzlJ1li22k84RV5R3TBlZivY5vlkR3UyKUd1e9fzbN5hAD21I9EfRWaGlSCc= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=kylinos.cn; spf=pass smtp.mailfrom=kylinos.cn; arc=none smtp.client-ip=124.126.103.232 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=kylinos.cn Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=kylinos.cn X-UUID: 7209109cfc4811f0b0f03b4cfa9209d1-20260128 X-CTIC-Tags: HR_CC_COUNT, HR_CC_DOMAIN_COUNT, HR_CC_NAME, HR_CC_NO_NAME, HR_CTE_8B HR_CTT_MISS, HR_DATE_H, HR_DATE_WKD, HR_DATE_ZONE, HR_FROM_NAME HR_SJ_DIGIT_LEN, HR_SJ_LANG, HR_SJ_LEN, HR_SJ_LETTER, HR_SJ_NOR_SYM HR_SJ_PHRASE, HR_SJ_PHRASE_LEN, HR_SJ_WS, HR_TO_COUNT, HR_TO_DOMAIN_COUNT HR_TO_NO_NAME, IP_UNTRUSTED, SRC_UNTRUSTED, IP_UNFAMILIAR, SRC_UNFAMILIAR DN_TRUSTED, SRC_TRUSTED, SA_TRUSTED, SA_EXISTED, SN_TRUSTED SN_EXISTED, SPF_NOPASS, DKIM_NOPASS, DMARC_NOPASS, CIE_GOOD_SPF CIE_UNKNOWN, GTI_FG_BS, GTI_RG_INFO, GTI_C_BU, AMN_GOOD ABX_MISS_RDNS X-CID-P-RULE: Release_Ham X-CID-O-INFO: VERSION:1.3.6,REQID:5946a7ab-2fca-46e7-b57f-f2ea221c3437,IP:10,U RL:0,TC:0,Content:-5,EDM:0,RT:0,SF:-5,FILE:0,BULK:0,RULE:Release_Ham,ACTIO N:release,TS:0 X-CID-INFO: VERSION:1.3.6,REQID:5946a7ab-2fca-46e7-b57f-f2ea221c3437,IP:10,URL :0,TC:0,Content:-5,EDM:0,RT:0,SF:-5,FILE:0,BULK:0,RULE:Release_Ham,ACTION: release,TS:0 X-CID-META: VersionHash:a9d874c,CLOUDID:c9a6ee56d66a87408c0ae6abc21a31ef,BulkI D:260128205414BPB3US2C,BulkQuantity:0,Recheck:0,SF:17|19|38|66|78|81|82|10 2|127|850|898,TC:nil,Content:0|15|50,EDM:-3,IP:-2,URL:0,File:nil,RT:nil,Bu lk:nil,QS:nil,BEC:nil,COL:0,OSI:0,OSA:0,AV:0,LES:1,SPR:NO,DKR:0,DKP:0,BRR: 0,BRE:0,ARC:0 X-CID-BVR: 2,SSN|SDN X-CID-BAS: 2,SSN|SDN,0,_ X-CID-FACTOR: TF_CID_SPAM_SNR,TF_CID_SPAM_FAS,TF_CID_SPAM_FSD X-CID-RHF: D41D8CD98F00B204E9800998ECF8427E X-UUID: 7209109cfc4811f0b0f03b4cfa9209d1-20260128 X-User: tianyaxiong@kylinos.cn Received: from localhost.localdomain [(175.2.149.138)] by mailgw.kylinos.cn (envelope-from ) (Generic MTA) with ESMTP id 1948363014; Wed, 28 Jan 2026 20:54:12 +0800 From: Yaxiong Tian To: mhiramat@kernel.org, rostedt@goodmis.org, axboe@kernel.dk, mathieu.desnoyers@efficios.com, corbet@lwn.net, skhan@linuxfoundation.org Cc: linux-trace-kernel@vger.kernel.org, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, Yaxiong Tian Subject: [PATCH v4 1/5] tracing: Rename `eval_map_wq` and allow other parts of tracing use it Date: Wed, 28 Jan 2026 20:53:57 +0800 Message-Id: <20260128125357.1711985-1-tianyaxiong@kylinos.cn> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20260128125117.1704853-1-tianyaxiong@kylinos.cn> References: <20260128125117.1704853-1-tianyaxiong@kylinos.cn> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" The eval_map_work_func() function, though queued in eval_map_wq, holds the trace_event_sem read-write lock for a long time during kernel boot. This causes blocking issues for other functions. Rename eval_map_wq to trace_init_wq and make it global, thereby allowing other parts of tracing to schedule work on this queue asynchronously and avoiding blockage of the main boot thread. Suggested-by: Steven Rostedt Signed-off-by: Yaxiong Tian Acked-by: Masami Hiramatsu (Google) --- kernel/trace/trace.c | 18 +++++++++--------- kernel/trace/trace.h | 1 + 2 files changed, 10 insertions(+), 9 deletions(-) diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index b1cb30a7b83d..01df88e77818 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -10774,7 +10774,7 @@ int tracing_init_dentry(void) extern struct trace_eval_map *__start_ftrace_eval_maps[]; extern struct trace_eval_map *__stop_ftrace_eval_maps[]; =20 -static struct workqueue_struct *eval_map_wq __initdata; +struct workqueue_struct *trace_init_wq __initdata; static struct work_struct eval_map_work __initdata; static struct work_struct tracerfs_init_work __initdata; =20 @@ -10790,15 +10790,15 @@ static int __init trace_eval_init(void) { INIT_WORK(&eval_map_work, eval_map_work_func); =20 - eval_map_wq =3D alloc_workqueue("eval_map_wq", WQ_UNBOUND, 0); - if (!eval_map_wq) { - pr_err("Unable to allocate eval_map_wq\n"); + trace_init_wq =3D alloc_workqueue("trace_init_wq", WQ_UNBOUND, 0); + if (!trace_init_wq) { + pr_err("Unable to allocate trace_init_wq\n"); /* Do work here */ eval_map_work_func(&eval_map_work); return -ENOMEM; } =20 - queue_work(eval_map_wq, &eval_map_work); + queue_work(trace_init_wq, &eval_map_work); return 0; } =20 @@ -10807,8 +10807,8 @@ subsys_initcall(trace_eval_init); static int __init trace_eval_sync(void) { /* Make sure the eval map updates are finished */ - if (eval_map_wq) - destroy_workqueue(eval_map_wq); + if (trace_init_wq) + destroy_workqueue(trace_init_wq); return 0; } =20 @@ -10969,9 +10969,9 @@ static __init int tracer_init_tracefs(void) if (ret) return 0; =20 - if (eval_map_wq) { + if (trace_init_wq) { INIT_WORK(&tracerfs_init_work, tracer_init_tracefs_work_func); - queue_work(eval_map_wq, &tracerfs_init_work); + queue_work(trace_init_wq, &tracerfs_init_work); } else { tracer_init_tracefs_work_func(NULL); } diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index de4e6713b84e..9e8d52503618 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -769,6 +769,7 @@ extern cpumask_var_t __read_mostly tracing_buffer_mask; extern unsigned long nsecs_to_usecs(unsigned long nsecs); =20 extern unsigned long tracing_thresh; +extern struct workqueue_struct *trace_init_wq __initdata; =20 /* PID filtering */ =20 --=20 2.25.1 From nobody Mon Feb 9 14:24:24 2026 Received: from mailgw.kylinos.cn (mailgw.kylinos.cn [124.126.103.232]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 4950C350A3B; Wed, 28 Jan 2026 12:55:04 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=124.126.103.232 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769604908; cv=none; b=cXVa7HkBGiR6HhgU5VL7okS8LRkhNwDDonEAF8WxbKTHd0mi06bkheXhUsx0A/G6W5U/gvRuvuujKqBp9/vmxSf3JiIsOruso/Tv4TepRz0z6Xz4N7R0dQVyDhZfiKDyObVfgl+uqjyQx4JbNRxmUU6p9zB7nyfKK+g3u76xvHg= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769604908; c=relaxed/simple; bh=u9s4Zh7bGHBx/TNk9+6VMEO/0lMdaa8WI35PIY7T4Uo=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version:Content-Type; b=or9HZZHUAQtfviHBBpdFYV5LVePGmud8yLn62LiokuwhSsHTdkfCatZzANVgE7kBGEgfcAc+ypXNgiUuM+jIwBd/DkZkJwP3M/8OlQjOOfEvjMSGOFmMHzSg7ViKsxYN4YrrWCI0owZYu5YBAUtp0vCdoLhQj08QXtZkeFxdG5A= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=kylinos.cn; spf=pass smtp.mailfrom=kylinos.cn; arc=none smtp.client-ip=124.126.103.232 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=kylinos.cn Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=kylinos.cn X-UUID: 8be6e48afc4811f0b0f03b4cfa9209d1-20260128 X-CTIC-Tags: HR_CC_COUNT, HR_CC_DOMAIN_COUNT, HR_CC_NAME, HR_CC_NO_NAME, HR_CTE_8B HR_CTT_TXT, HR_DATE_H, HR_DATE_WKD, HR_DATE_ZONE, HR_FROM_NAME HR_SJ_DIGIT_LEN, HR_SJ_LANG, HR_SJ_LEN, HR_SJ_LETTER, HR_SJ_NOR_SYM HR_SJ_PHRASE, HR_SJ_PHRASE_LEN, HR_SJ_WS, HR_TO_COUNT, HR_TO_DOMAIN_COUNT HR_TO_NO_NAME, IP_UNTRUSTED, SRC_UNTRUSTED, IP_UNFAMILIAR, SRC_UNFAMILIAR DN_TRUSTED, SRC_TRUSTED, SA_TRUSTED, SA_EXISTED, SN_TRUSTED SN_EXISTED, SPF_NOPASS, DKIM_NOPASS, DMARC_NOPASS, CIE_GOOD_SPF CIE_UNKNOWN, GTI_FG_BS, GTI_RG_INFO, GTI_C_BU, AMN_GOOD ABX_MISS_RDNS X-CID-P-RULE: Release_Ham X-CID-O-INFO: VERSION:1.3.6,REQID:a3bf609d-aa25-4953-b91c-91bb7fbcfcfe,IP:10,U RL:0,TC:0,Content:-25,EDM:-25,RT:0,SF:-5,FILE:0,BULK:0,RULE:Release_Ham,AC TION:release,TS:-45 X-CID-INFO: VERSION:1.3.6,REQID:a3bf609d-aa25-4953-b91c-91bb7fbcfcfe,IP:10,URL :0,TC:0,Content:-25,EDM:-25,RT:0,SF:-5,FILE:0,BULK:0,RULE:NOTI_GNA5D1EA,AC TION:release,TS:-45 X-CID-META: VersionHash:a9d874c,CLOUDID:3a6db0938442dd24d7d66b8726d0fb8c,BulkI D:260128205459GMRIXNBL,BulkQuantity:0,Recheck:0,SF:17|19|38|66|78|81|82|10 2|127|850|898,TC:nil,Content:0|15|50,EDM:2,IP:-2,URL:0,File:nil,RT:nil,Bul k:nil,QS:nil,BEC:nil,COL:0,OSI:0,OSA:0,AV:0,LES:1,SPR:NO,DKR:0,DKP:0,BRR:0 ,BRE:0,ARC:0 X-CID-BVR: 2,SSN|SDN X-CID-BAS: 2,SSN|SDN,0,_ X-CID-FACTOR: TF_CID_SPAM_SNR,TF_CID_SPAM_FAS,TF_CID_SPAM_FSD X-CID-RHF: D41D8CD98F00B204E9800998ECF8427E X-UUID: 8be6e48afc4811f0b0f03b4cfa9209d1-20260128 X-User: tianyaxiong@kylinos.cn Received: from localhost.localdomain [(175.2.149.138)] by mailgw.kylinos.cn (envelope-from ) (Generic MTA) with ESMTP id 1348324856; Wed, 28 Jan 2026 20:54:56 +0800 From: Yaxiong Tian To: mhiramat@kernel.org, rostedt@goodmis.org, axboe@kernel.dk, mathieu.desnoyers@efficios.com, corbet@lwn.net, skhan@linuxfoundation.org Cc: linux-trace-kernel@vger.kernel.org, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, Yaxiong Tian Subject: [PATCH v4 2/5] tracing: add trace_async_init boot parameter Date: Wed, 28 Jan 2026 20:54:21 +0800 Message-Id: <20260128125421.1713134-1-tianyaxiong@kylinos.cn> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20260128125117.1704853-1-tianyaxiong@kylinos.cn> References: <20260128125117.1704853-1-tianyaxiong@kylinos.cn> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Some users prioritize faster kernel boot time. However, the tracing subsystem, being a critical infrastructure, traditionally initializes serially. To balance the need for deterministic timing in tracing against the demand for quicker startup, the trace_async_init boot parameter is introduced. When users do not require strict timing determinism for trace features=E2=80=94or do not use tracing at all during boot=E2=80=94they can = add this cmdline parameter to accelerate kernel startup. Suggested-by: Masami Hiramatsu (Google) Signed-off-by: Yaxiong Tian Acked-by: Masami Hiramatsu (Google) --- Documentation/admin-guide/kernel-parameters.txt | 8 ++++++++ kernel/trace/trace.c | 9 +++++++++ kernel/trace/trace.h | 1 + 3 files changed, 18 insertions(+) diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentatio= n/admin-guide/kernel-parameters.txt index 6b3460701910..d46fdfbfa961 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -7851,6 +7851,14 @@ Kernel parameters This option can also be set at run time via the sysctl option: kernel/traceoff_on_warning =20 + trace_async_init + [FTRACE] Enable this option when faster boot time is the + priority. It is beneficial in scenarios where users either + do not require a strict initialization order for certain + tracing features during boot, or do not use tracing at all + in the early boot phase. This can lead to measurable + improvements in kernel startup speed. + transparent_hugepage=3D [KNL] Format: [always|madvise|never] diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 01df88e77818..9d571841fc84 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -1725,6 +1725,15 @@ static int __init set_tracing_thresh(char *str) } __setup("tracing_thresh=3D", set_tracing_thresh); =20 +bool trace_async_init __initdata; + +static int __init setup_trace_async_init(char *str) +{ + trace_async_init =3D true; + return 1; +} +__setup("trace_async_init", setup_trace_async_init); + unsigned long nsecs_to_usecs(unsigned long nsecs) { return nsecs / 1000; diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index 9e8d52503618..63ae83d7bd1c 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -769,6 +769,7 @@ extern cpumask_var_t __read_mostly tracing_buffer_mask; extern unsigned long nsecs_to_usecs(unsigned long nsecs); =20 extern unsigned long tracing_thresh; +extern bool trace_async_init __initdata; extern struct workqueue_struct *trace_init_wq __initdata; =20 /* PID filtering */ --=20 2.25.1 From nobody Mon Feb 9 14:24:24 2026 Received: from mailgw.kylinos.cn (mailgw.kylinos.cn [124.126.103.232]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 4CF6934FF59; Wed, 28 Jan 2026 12:55:18 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=124.126.103.232 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769604921; cv=none; b=sdq1XKHXZunSDV1ImO+OynF9eJ4jEsFJJ8duoJKuKuQOig3IM1sGMk1DkYpUtlRSQW96rcz39iraJ2kW30KqBvVh/BV6j8NwalokMVJBDeoioPfUROgOgtU/KSNf6tfQ9D+MguPCkw/ErPuyDNcDuo5dEMzUvFli8/MuqpDneNk= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769604921; c=relaxed/simple; bh=nvx0pzDMUCUQRnDLUIB4oTe85CB/B2famYO/awEkHsQ=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=Z+uN7ZkZBqqro4jZqZUuqdZbkPv95jVs+xHz4G5fObp1GjKcn7QFx3ycVpiHZsgPKxeGOGBQ7zQuXL9wIOvP3EILaeqXQxNWJQe1A+/A4iTR0Ft2KEs+8KPj1n1y9sjTj6aPjgGn+fjFmM9+uBxKshQR3KNM88/qqHQNePFgixc= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=kylinos.cn; spf=pass smtp.mailfrom=kylinos.cn; arc=none smtp.client-ip=124.126.103.232 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=kylinos.cn Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=kylinos.cn X-UUID: 9448c030fc4811f0b0f03b4cfa9209d1-20260128 X-CTIC-Tags: HR_CC_COUNT, HR_CC_DOMAIN_COUNT, HR_CC_NAME, HR_CC_NO_NAME, HR_CTE_8B HR_CTT_MISS, HR_DATE_H, HR_DATE_WKD, HR_DATE_ZONE, HR_FROM_NAME HR_SJ_DIGIT_LEN, HR_SJ_LANG, HR_SJ_LEN, HR_SJ_LETTER, HR_SJ_NOR_SYM HR_SJ_PHRASE, HR_SJ_PHRASE_LEN, HR_SJ_WS, HR_TO_COUNT, HR_TO_DOMAIN_COUNT HR_TO_NO_NAME, IP_UNTRUSTED, SRC_UNTRUSTED, IP_UNFAMILIAR, SRC_UNFAMILIAR DN_TRUSTED, SRC_TRUSTED, SA_TRUSTED, SA_EXISTED, SN_TRUSTED SN_EXISTED, SPF_NOPASS, DKIM_NOPASS, DMARC_NOPASS, CIE_GOOD_SPF CIE_UNKNOWN, GTI_FG_BS, GTI_RG_INFO, GTI_C_BU, AMN_GOOD ABX_MISS_RDNS X-CID-P-RULE: Release_Ham X-CID-O-INFO: VERSION:1.3.6,REQID:168305d2-bc71-444d-a98e-7baeb28e2e6f,IP:10,U RL:0,TC:0,Content:0,EDM:0,RT:0,SF:-5,FILE:0,BULK:0,RULE:Release_Ham,ACTION :release,TS:5 X-CID-INFO: VERSION:1.3.6,REQID:168305d2-bc71-444d-a98e-7baeb28e2e6f,IP:10,URL :0,TC:0,Content:0,EDM:0,RT:0,SF:-5,FILE:0,BULK:0,RULE:Release_Ham,ACTION:r elease,TS:5 X-CID-META: VersionHash:a9d874c,CLOUDID:232bfff06d43625ae7096e50e9305987,BulkI D:2601282055117T6T78JL,BulkQuantity:0,Recheck:0,SF:17|19|38|66|78|81|82|10 2|127|850|898,TC:nil,Content:0|15|50,EDM:-3,IP:-2,URL:0,File:nil,RT:nil,Bu lk:nil,QS:nil,BEC:nil,COL:0,OSI:0,OSA:0,AV:0,LES:1,SPR:NO,DKR:0,DKP:0,BRR: 0,BRE:0,ARC:0 X-CID-BVR: 2,SSN|SDN X-CID-BAS: 2,SSN|SDN,0,_ X-CID-FACTOR: TF_CID_SPAM_FAS,TF_CID_SPAM_FSD,TF_CID_SPAM_SNR X-CID-RHF: D41D8CD98F00B204E9800998ECF8427E X-UUID: 9448c030fc4811f0b0f03b4cfa9209d1-20260128 X-User: tianyaxiong@kylinos.cn Received: from localhost.localdomain [(175.2.149.138)] by mailgw.kylinos.cn (envelope-from ) (Generic MTA) with ESMTP id 339552490; Wed, 28 Jan 2026 20:55:10 +0800 From: Yaxiong Tian To: mhiramat@kernel.org, rostedt@goodmis.org, axboe@kernel.dk, mathieu.desnoyers@efficios.com, corbet@lwn.net, skhan@linuxfoundation.org Cc: linux-trace-kernel@vger.kernel.org, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, Yaxiong Tian Subject: [PATCH v4 3/5] tracing/kprobes: Skip setup_boot_kprobe_events() when no cmdline event Date: Wed, 28 Jan 2026 20:55:07 +0800 Message-Id: <20260128125507.1715149-1-tianyaxiong@kylinos.cn> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20260128125117.1704853-1-tianyaxiong@kylinos.cn> References: <20260128125117.1704853-1-tianyaxiong@kylinos.cn> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" When the 'kprobe_event=3D' kernel command-line parameter is not provided, there is no need to execute setup_boot_kprobe_events(). This change optimizes the initialization function init_kprobe_trace() by skipping unnecessary work and effectively prevents potential blocking that could arise from contention on the event_mutex lock in subsequent operations. Signed-off-by: Yaxiong Tian Acked-by: Masami Hiramatsu (Google) --- kernel/trace/trace_kprobe.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c index 9953506370a5..89d2740f7bb5 100644 --- a/kernel/trace/trace_kprobe.c +++ b/kernel/trace/trace_kprobe.c @@ -2048,6 +2048,10 @@ static __init int init_kprobe_trace(void) trace_create_file("kprobe_profile", TRACE_MODE_READ, NULL, NULL, &kprobe_profile_ops); =20 + /* If no 'kprobe_event=3D' cmd is provided, return directly. */ + if (kprobe_boot_events_buf[0] =3D=3D '\0') + return 0; + setup_boot_kprobe_events(); =20 return 0; --=20 2.25.1 From nobody Mon Feb 9 14:24:24 2026 Received: from mailgw.kylinos.cn (mailgw.kylinos.cn [124.126.103.232]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 72A68238D54; Wed, 28 Jan 2026 12:55:51 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=124.126.103.232 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769604955; cv=none; b=FDtm3O8aWShetppwuo1KyioGfyP/cGV86lk9AslN6ljvfOiOFuuGdkhysXOadDQEtGd4hyw8QyjtuSFluu8HqjMzs38AljPtt3/sSsIfqT0kRpPiFEIzTGtaYjoUDuY+ZbUqwe1DsRl6VU+LhCaQRhcOqHaIv0Vjzqu+o2n0K94= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769604955; c=relaxed/simple; bh=/vPdkdTXJD9N1vOxSRrp0toy8+xM6EB1j5Ybi7pprXg=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=f/siDa/0Lfmr9e5vTGLulO33QUKmVcakrLdaOFeTwoNIGb3D9N1gv8CgSKwXbnP6cPEOHt3C/TIbVHQJMJJUVske/B+qie2gB5j9kfiJAhO64/5U1hh+R6eJLvTdhb4hrRgPpRX7LLxrOp44kvUuGlQwj9qnbt4mxPM4f2xY4xI= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=kylinos.cn; spf=pass smtp.mailfrom=kylinos.cn; arc=none smtp.client-ip=124.126.103.232 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=kylinos.cn Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=kylinos.cn X-UUID: a960c6f2fc4811f0b0f03b4cfa9209d1-20260128 X-CTIC-Tags: HR_CC_COUNT, HR_CC_DOMAIN_COUNT, HR_CC_NAME, HR_CC_NO_NAME, HR_CTE_8B HR_CTT_MISS, HR_DATE_H, HR_DATE_WKD, HR_DATE_ZONE, HR_FROM_NAME HR_SJ_DIGIT_LEN, HR_SJ_LANG, HR_SJ_LEN, HR_SJ_LETTER, HR_SJ_NOR_SYM HR_SJ_PHRASE, HR_SJ_PHRASE_LEN, HR_SJ_WS, HR_TO_COUNT, HR_TO_DOMAIN_COUNT HR_TO_NO_NAME, IP_UNTRUSTED, SRC_UNTRUSTED, IP_UNFAMILIAR, SRC_UNFAMILIAR DN_TRUSTED, SRC_TRUSTED, SA_TRUSTED, SA_EXISTED, SN_TRUSTED SN_EXISTED, SPF_NOPASS, DKIM_NOPASS, DMARC_NOPASS, CIE_GOOD_SPF CIE_UNKNOWN, GTI_FG_BS, GTI_RG_INFO, GTI_C_BU, AMN_GOOD ABX_MISS_RDNS X-CID-P-RULE: Release_Ham X-CID-O-INFO: VERSION:1.3.6,REQID:8e88349a-781b-438f-9161-6f9a1d4e271e,IP:10,U RL:0,TC:0,Content:0,EDM:0,RT:0,SF:-5,FILE:0,BULK:0,RULE:Release_Ham,ACTION :release,TS:5 X-CID-INFO: VERSION:1.3.6,REQID:8e88349a-781b-438f-9161-6f9a1d4e271e,IP:10,URL :0,TC:0,Content:0,EDM:0,RT:0,SF:-5,FILE:0,BULK:0,RULE:Release_Ham,ACTION:r elease,TS:5 X-CID-META: VersionHash:a9d874c,CLOUDID:60aa5a7183b5b16d44e851238032f6f7,BulkI D:2601282055470JTHSZ4B,BulkQuantity:0,Recheck:0,SF:17|19|38|66|78|81|82|10 2|127|850|898,TC:nil,Content:0|15|50,EDM:-3,IP:-2,URL:0,File:nil,RT:nil,Bu lk:nil,QS:nil,BEC:nil,COL:0,OSI:0,OSA:0,AV:0,LES:1,SPR:NO,DKR:0,DKP:0,BRR: 0,BRE:0,ARC:0 X-CID-BVR: 2,SSN|SDN X-CID-BAS: 2,SSN|SDN,0,_ X-CID-FACTOR: TF_CID_SPAM_FAS,TF_CID_SPAM_FSD,TF_CID_SPAM_SNR X-CID-RHF: D41D8CD98F00B204E9800998ECF8427E X-UUID: a960c6f2fc4811f0b0f03b4cfa9209d1-20260128 X-User: tianyaxiong@kylinos.cn Received: from localhost.localdomain [(175.2.149.138)] by mailgw.kylinos.cn (envelope-from ) (Generic MTA) with ESMTP id 1854064231; Wed, 28 Jan 2026 20:55:45 +0800 From: Yaxiong Tian To: mhiramat@kernel.org, rostedt@goodmis.org, axboe@kernel.dk, mathieu.desnoyers@efficios.com, corbet@lwn.net, skhan@linuxfoundation.org Cc: linux-trace-kernel@vger.kernel.org, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, Yaxiong Tian Subject: [PATCH v4 4/5] tracing/kprobes: Make setup_boot_kprobe_events() asynchronous when trace_async_init set Date: Wed, 28 Jan 2026 20:55:18 +0800 Message-Id: <20260128125518.1715682-1-tianyaxiong@kylinos.cn> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20260128125117.1704853-1-tianyaxiong@kylinos.cn> References: <20260128125117.1704853-1-tianyaxiong@kylinos.cn> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" During kernel boot, the setup_boot_kprobe_events() function causes significant delays, increasing overall startup time. The root cause is a lock contention chain: its child function enable_boot_kprobe_events() requires the event_mutex, which is already held by early_event_add_tracer(). early_event_add_tracer() itself is blocked waiting for the trace_event_sem read-write lock, which is held for an extended period by trace_event_update_all(). To resolve this, when the trace_async_init parameter is enabled, the execution of setup_boot_kprobe_events() is moved to the trace_init_wq workqueue, allowing it to run asynchronously. Signed-off-by: Yaxiong Tian Acked-by: Masami Hiramatsu (Google) --- kernel/trace/trace_kprobe.c | 14 +++++++++++++- 1 file changed, 13 insertions(+), 1 deletion(-) diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c index 89d2740f7bb5..fe69fc03018b 100644 --- a/kernel/trace/trace_kprobe.c +++ b/kernel/trace/trace_kprobe.c @@ -2031,6 +2031,13 @@ static __init int init_kprobe_trace_early(void) } core_initcall(init_kprobe_trace_early); =20 +static struct work_struct kprobe_trace_work __initdata; + +static void __init kprobe_trace_works_func(struct work_struct *work) +{ + setup_boot_kprobe_events(); +} + /* Make a tracefs interface for controlling probe points */ static __init int init_kprobe_trace(void) { @@ -2052,7 +2059,12 @@ static __init int init_kprobe_trace(void) if (kprobe_boot_events_buf[0] =3D=3D '\0') return 0; =20 - setup_boot_kprobe_events(); + if (trace_init_wq && trace_async_init) { + INIT_WORK(&kprobe_trace_work, kprobe_trace_works_func); + queue_work(trace_init_wq, &kprobe_trace_work); + } else { + setup_boot_kprobe_events(); + } =20 return 0; } --=20 2.25.1 From nobody Mon Feb 9 14:24:24 2026 Received: from mailgw.kylinos.cn (mailgw.kylinos.cn [124.126.103.232]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id C4E1234FF59; Wed, 28 Jan 2026 12:56:12 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=124.126.103.232 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769604975; cv=none; b=fFSDbLa6lF61EaiK9o959gRv8uNJd7m42VhidtssBZ3bSVoRg5jm++kbkscvypEf6GlFF7cHi5+MXJpVJTrHQiR0XC5DpkkKMl64+BKqVG95junSJkv5o7unSG/jlsFk1wMTntn8fGTpwbN/3FROuRkezC1dzdCyuOJzmRz3mWU= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769604975; c=relaxed/simple; bh=9IJ4CsI3azrt2akw/y/viNEErdy5VYNOL4a3Nwm3XmY=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=tvXc8xtCjhSHy3xEir52ccNpt3yrSWAvbpxis3a1eOtH/gW9IzWt05tJJr44tHVt8+KmAVbd1X4jm4qSF7G+tnwNXbG+sVJQ5dPDckBOt43YtXEJRGdw+v56IGvmV/oUztiGyZrT+usTV/vMr/4rS+PvDD7ddcI//qUxIV+dx3k= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=kylinos.cn; spf=pass smtp.mailfrom=kylinos.cn; arc=none smtp.client-ip=124.126.103.232 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=kylinos.cn Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=kylinos.cn X-UUID: b64d3e4afc4811f0b0f03b4cfa9209d1-20260128 X-CTIC-Tags: HR_CC_COUNT, HR_CC_DOMAIN_COUNT, HR_CC_NAME, HR_CC_NO_NAME, HR_CTE_8B HR_CTT_MISS, HR_DATE_H, HR_DATE_WKD, HR_DATE_ZONE, HR_FROM_NAME HR_SJ_DIGIT_LEN, HR_SJ_LANG, HR_SJ_LEN, HR_SJ_LETTER, HR_SJ_NOR_SYM HR_SJ_PHRASE, HR_SJ_PHRASE_LEN, HR_SJ_WS, HR_TO_COUNT, HR_TO_DOMAIN_COUNT HR_TO_NO_NAME, IP_UNTRUSTED, SRC_UNTRUSTED, IP_UNFAMILIAR, SRC_UNFAMILIAR DN_TRUSTED, SRC_TRUSTED, SA_TRUSTED, SA_EXISTED, SN_TRUSTED SN_EXISTED, SPF_NOPASS, DKIM_NOPASS, DMARC_NOPASS, CIE_GOOD_SPF CIE_UNKNOWN, GTI_FG_BS, GTI_RG_INFO, GTI_C_BU, AMN_GOOD ABX_MISS_RDNS X-CID-P-RULE: Release_Ham X-CID-O-INFO: VERSION:1.3.6,REQID:92eb13ed-6a87-41e9-ad00-44c723de46b5,IP:10,U RL:0,TC:0,Content:-25,EDM:0,RT:0,SF:-5,FILE:0,BULK:0,RULE:Release_Ham,ACTI ON:release,TS:-20 X-CID-INFO: VERSION:1.3.6,REQID:92eb13ed-6a87-41e9-ad00-44c723de46b5,IP:10,URL :0,TC:0,Content:-25,EDM:0,RT:0,SF:-5,FILE:0,BULK:0,RULE:Release_Ham,ACTION :release,TS:-20 X-CID-META: VersionHash:a9d874c,CLOUDID:3c76fa077e3e311b2dc2ad8b2ae08010,BulkI D:2601282056087V6MGO1B,BulkQuantity:0,Recheck:0,SF:17|19|38|66|78|81|82|10 2|127|850|898,TC:nil,Content:0|15|50,EDM:-3,IP:-2,URL:0,File:nil,RT:nil,Bu lk:nil,QS:nil,BEC:nil,COL:0,OSI:0,OSA:0,AV:0,LES:1,SPR:NO,DKR:0,DKP:0,BRR: 0,BRE:0,ARC:0 X-CID-BVR: 2,SSN|SDN X-CID-BAS: 2,SSN|SDN,0,_ X-CID-FACTOR: TF_CID_SPAM_SNR,TF_CID_SPAM_FAS,TF_CID_SPAM_FSD X-CID-RHF: D41D8CD98F00B204E9800998ECF8427E X-UUID: b64d3e4afc4811f0b0f03b4cfa9209d1-20260128 X-User: tianyaxiong@kylinos.cn Received: from localhost.localdomain [(175.2.149.138)] by mailgw.kylinos.cn (envelope-from ) (Generic MTA) with ESMTP id 1998762990; Wed, 28 Jan 2026 20:56:07 +0800 From: Yaxiong Tian To: mhiramat@kernel.org, rostedt@goodmis.org, axboe@kernel.dk, mathieu.desnoyers@efficios.com, corbet@lwn.net, skhan@linuxfoundation.org Cc: linux-trace-kernel@vger.kernel.org, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, Yaxiong Tian Subject: [PATCH v4 5/5] blktrace: Make init_blk_tracer() asynchronous when trace_async_init set Date: Wed, 28 Jan 2026 20:55:54 +0800 Message-Id: <20260128125554.1717261-1-tianyaxiong@kylinos.cn> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20260128125117.1704853-1-tianyaxiong@kylinos.cn> References: <20260128125117.1704853-1-tianyaxiong@kylinos.cn> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" The init_blk_tracer() function causes significant boot delay as it waits for the trace_event_sem lock held by trace_event_update_all(). Specifically, its child function register_trace_event() requires this lock, which is occupied for an extended period during boot. To resolve this, when the trace_async_init parameter is enabled, the execution of primary init_blk_tracer() is moved to the trace_init_wq workqueue, allowing it to run asynchronously. and prevent blocking the main boot thread. Signed-off-by: Yaxiong Tian Acked-by: Jens Axboe Acked-by: Masami Hiramatsu (Google) --- kernel/trace/blktrace.c | 23 ++++++++++++++++++++++- 1 file changed, 22 insertions(+), 1 deletion(-) diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c index d031c8d80be4..56c7270ec447 100644 --- a/kernel/trace/blktrace.c +++ b/kernel/trace/blktrace.c @@ -1832,7 +1832,9 @@ static struct trace_event trace_blk_event =3D { .funcs =3D &trace_blk_event_funcs, }; =20 -static int __init init_blk_tracer(void) +static struct work_struct blktrace_works __initdata; + +static int __init __init_blk_tracer(void) { if (!register_trace_event(&trace_blk_event)) { pr_warn("Warning: could not register block events\n"); @@ -1852,6 +1854,25 @@ static int __init init_blk_tracer(void) return 0; } =20 +static void __init blktrace_works_func(struct work_struct *work) +{ + __init_blk_tracer(); +} + +static int __init init_blk_tracer(void) +{ + int ret =3D 0; + + if (trace_init_wq && trace_async_init) { + INIT_WORK(&blktrace_works, blktrace_works_func); + queue_work(trace_init_wq, &blktrace_works); + } else { + ret =3D __init_blk_tracer(); + } + + return ret; +} + device_initcall(init_blk_tracer); =20 static int blk_trace_remove_queue(struct request_queue *q) --=20 2.25.1