From nobody Wed Feb 11 03:42:09 2026 Received: from relay.hostedemail.com (smtprelay0011.hostedemail.com [216.40.44.11]) (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 08FBC611E; Sun, 8 Feb 2026 00:11:05 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=216.40.44.11 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770509466; cv=none; b=JD6uYzBQyuAYloE7hbTezrFbWrbagbVwr9o7BD1Z62An+UrofHhgP9BnPSnMZvap+Z5matD/Ghkf2YGRNqOZjUBuhkD48/E/FQCdFLP1AqxXXmyl+mhVVyTutFhwqyhuDOppMBsDZ67bGIQIO9kkuEGNtKhn85TREs7F9QVaNYU= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770509466; c=relaxed/simple; bh=7W2sMZ0eosKj8m1q8MSjX9tUw7pvfVXCUDEyf83/yhY=; h=Date:From:To:Cc:Subject:Message-ID:MIME-Version:Content-Type; b=sfHNs04/tXd3AiL3QYiwF94pBFe7Yymd9QXzrDXN0bfwyMB3+2BsJ8cp7GIwNTkOOZBowl/X4Ztc9aM0xDB/xmTQh/gcw1JjyGejqOExWN4fXUxAg9tjf8WxV0T9RS5pSKv8jBsVZcRHn6lBg5NBJ8unbE1K8tuqoLCzWWwEq2Y= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=goodmis.org; spf=pass smtp.mailfrom=goodmis.org; arc=none smtp.client-ip=216.40.44.11 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=goodmis.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=goodmis.org Received: from omf04.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay10.hostedemail.com (Postfix) with ESMTP id 77E22C023C; Sun, 8 Feb 2026 00:11:04 +0000 (UTC) Received: from [HIDDEN] (Authenticated sender: rostedt@goodmis.org) by omf04.hostedemail.com (Postfix) with ESMTPA id DCB6320024; Sun, 8 Feb 2026 00:11:02 +0000 (UTC) Date: Sat, 7 Feb 2026 19:11:01 -0500 From: Steven Rostedt To: LKML , Linux trace kernel Cc: Masami Hiramatsu , Mathieu Desnoyers Subject: [PATCH] tracing: Clean up use of trace_create_maxlat_file() Message-ID: <20260207191101.0e014abd@robin> X-Mailer: Claws Mail 4.3.1 (GTK 3.24.51; x86_64-redhat-linux-gnu) 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 X-Rspamd-Server: rspamout07 X-Rspamd-Queue-Id: DCB6320024 X-Stat-Signature: 5hsg463txoenx3jim5bewf5igwjw83b6 X-Session-Marker: 726F737465647440676F6F646D69732E6F7267 X-Session-ID: U2FsdGVkX1/nHpDIGJHH9htKsiOHf3hiTvoOxdUdWbQ= X-HE-Tag: 1770509462-175938 X-HE-Meta: U2FsdGVkX1/U/+kRY70yWKOl3n/LVlo91EobYRx1stSgBCxn9RiaT6dkZtndIoJUguPKaZfcN6gw8ICMJoTutBccVJp8G9GC5gJXVsvwcw6GdfZ3n52zDeaKvaV/C4Vyz72x0Q+zt9dhdgbosXxtWGACjczr38B+z5xCasVXG7kK/eDwaPqfeehoCQqwBGanRajRkf68Hf7gRbIySNsTyI7RC1moMhRPCeuQL1bdTtC1OCqdVDAztd8tirrkYDGALm5siImDYZAJwfo+UhJd+FbPiWJU8uZMwI4nMWZCSCTEnk/xaaBCq+GTK1Se1yJj3FqUl+WuAzZUgkOPQ+qTstbrVNg3iVGn0N13Q2ecPvhBke7fz++SDkbcUoIztpQ0GfCCFwc+52n4kn7i5b2rfpwPgV4VR/Cl2Z/+AeNNlTkyvdSJiXEEtmBCHKHARdvOidweh/FyZAQ2Dw6xFB4iuQ== Content-Type: text/plain; charset="utf-8" From: Steven Rostedt In trace.c, the function trace_create_maxlat_file() is defined behind the #ifdef CONFIG_TRACER_MAX_TRACE block. The #else part defines it as: #define trace_create_maxlat_file(tr, d_tracer) \ trace_create_file("tracing_max_latency", TRACE_MODE_WRITE, \ d_tracer, tr, &tracing_max_lat_fops) But the one place that it it used has: #ifdef CONFIG_TRACER_MAX_TRACE trace_create_maxlat_file(tr, d_tracer); #endif Which is pointless and also wrong! It only gets created when both CONFIG_TRACE_MAX_TRACE and CONFIG_FS_NOTIFY is defined, but the file itself should not be dependent on CONFIG_FS_NOTIFY. Always create that file when TRACE_MAX_TRACE is defined regardless if FS_NOTIFY is or is not. Signed-off-by: Steven Rostedt (Google) --- Changes since v2: https://patch.msgid.link/20260206230410.4ed96e9f@robin - On further inspection, tracing_max_latency should always be created if CONFIG_TRACER_MAX_TRACE is defined regardless if CONFIG_FS_NOTIFY is. kernel/trace/trace.c | 38 ++++++++++++++++---------------------- 1 file changed, 16 insertions(+), 22 deletions(-) diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 702ef851db45..d02c4004c718 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -1912,10 +1912,7 @@ static ssize_t trace_seq_to_buffer(struct trace_seq = *s, void *buf, size_t cnt) unsigned long __read_mostly tracing_thresh; =20 #ifdef CONFIG_TRACER_MAX_TRACE -static const struct file_operations tracing_max_lat_fops; - #ifdef LATENCY_FS_NOTIFY - static struct workqueue_struct *fsnotify_wq; =20 static void latency_fsnotify_workfn(struct work_struct *work) @@ -1932,17 +1929,6 @@ static void latency_fsnotify_workfn_irq(struct irq_w= ork *iwork) queue_work(fsnotify_wq, &tr->fsnotify_work); } =20 -static void trace_create_maxlat_file(struct trace_array *tr, - struct dentry *d_tracer) -{ - INIT_WORK(&tr->fsnotify_work, latency_fsnotify_workfn); - init_irq_work(&tr->fsnotify_irqwork, latency_fsnotify_workfn_irq); - tr->d_max_latency =3D trace_create_file("tracing_max_latency", - TRACE_MODE_WRITE, - d_tracer, tr, - &tracing_max_lat_fops); -} - __init static int latency_fsnotify_init(void) { fsnotify_wq =3D alloc_workqueue("tr_max_lat_wq", @@ -1967,14 +1953,22 @@ void latency_fsnotify(struct trace_array *tr) */ irq_work_queue(&tr->fsnotify_irqwork); } +#endif /* !LATENCY_FS_NOTIFY */ =20 -#else /* !LATENCY_FS_NOTIFY */ - -#define trace_create_maxlat_file(tr, d_tracer) \ - trace_create_file("tracing_max_latency", TRACE_MODE_WRITE, \ - d_tracer, tr, &tracing_max_lat_fops) +static const struct file_operations tracing_max_lat_fops; =20 +static void trace_create_maxlat_file(struct trace_array *tr, + struct dentry *d_tracer) +{ +#ifdef LATENCY_FS_NOTIFY + INIT_WORK(&tr->fsnotify_work, latency_fsnotify_workfn); + init_irq_work(&tr->fsnotify_irqwork, latency_fsnotify_workfn_irq); #endif + tr->d_max_latency =3D trace_create_file("tracing_max_latency", + TRACE_MODE_WRITE, + d_tracer, tr, + &tracing_max_lat_fops); +} =20 /* * Copy the new maximum trace into the separate maximum-trace @@ -2109,7 +2103,9 @@ update_max_tr_single(struct trace_array *tr, struct t= ask_struct *tsk, int cpu) __update_max_tr(tr, tsk, cpu); arch_spin_unlock(&tr->max_lock); } - +#else /* !CONFIG_TRACER_MAX_TRACE */ +static inline void trace_create_maxlat_file(struct trace_array *tr, + struct dentry *d_tracer) { } #endif /* CONFIG_TRACER_MAX_TRACE */ =20 struct pipe_wait { @@ -10664,9 +10660,7 @@ init_tracer_tracefs(struct trace_array *tr, struct = dentry *d_tracer) =20 create_trace_options_dir(tr); =20 -#ifdef CONFIG_TRACER_MAX_TRACE trace_create_maxlat_file(tr, d_tracer); -#endif =20 if (ftrace_create_function_files(tr, d_tracer)) MEM_FAIL(1, "Could not allocate function filter files"); --=20 2.51.0