averello/linux-stable-mirror
1
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git synced 2026-03-03 18:28:01 +01:00
Code Issues Packages Projects Releases Wiki Activity

tracing: Clean up use of trace_create_maxlat_file()

Browse Source 
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.

Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Link: https://patch.msgid.link/20260207191101.0e014abd@robin
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
This commit is contained in:
Steven Rostedt
2026-02-07 19:11:01 -05:00
committed by Steven Rostedt (Google)
parent 326669faf3
commit ba73713da5
1 changed files with 16 additions and 22 deletions
Download Patch File Download Diff File Expand all files Collapse all files

38
kernel/trace/trace.c
View File

@@ -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;
#ifdef CONFIG_TRACER_MAX_TRACE
static const struct file_operations tracing_max_lat_fops;
#ifdef LATENCY_FS_NOTIFY
static struct workqueue_struct *fsnotify_wq;
static void latency_fsnotify_workfn(struct work_struct *work)
@@ -1932,17 +1929,6 @@ static void latency_fsnotify_workfn_irq(struct irq_work *iwork)
queue_work(fsnotify_wq, &tr->fsnotify_work);
}
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 = 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 = 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 */
#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;
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 = trace_create_file("tracing_max_latency",
TRACE_MODE_WRITE,
d_tracer, tr,
&tracing_max_lat_fops);
}
/*
* Copy the new maximum trace into the separate maximum-trace
@@ -2109,7 +2103,9 @@ update_max_tr_single(struct trace_array *tr, struct task_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 */
struct pipe_wait {
@@ -10664,9 +10660,7 @@ init_tracer_tracefs(struct trace_array *tr, struct dentry *d_tracer)
create_trace_options_dir(tr);
#ifdef CONFIG_TRACER_MAX_TRACE
trace_create_maxlat_file(tr, d_tracer);
#endif
if (ftrace_create_function_files(tr, d_tracer))
MEM_FAIL(1, "Could not allocate function filter files");