Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 8656e7a2 authored by Frederic Weisbecker's avatar Frederic Weisbecker Committed by Ingo Molnar
Browse files

tracing/core: make the per cpu trace files in per cpu directories 



Impact: restructure the VFS layout of per CPU trace buffers

The per cpu trace files are all in a single directory:
/debug/tracing/per_cpu. In case of a large number of cpu, the
content of this directory becomes messy so we create now one
directory per cpu inside /debug/tracing/per_cpu which contain
each their own trace_pipe and trace files.

Ie:

 /debug/tracing$ ls -R per_cpu
 per_cpu:
 cpu0  cpu1

 per_cpu/cpu0:
 trace  trace_pipe

 per_cpu/cpu1:
 trace  trace_pipe

Signed-off-by: default avatarFrederic Weisbecker <fweisbec@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent f4abfb8d

kernel/trace/trace.c

+14 −11
Original line number Diff line number Diff line
@@ -3061,28 +3061,31 @@ struct dentry *tracing_dentry_percpu(void) 
static void tracing_init_debugfs_percpu(long cpu)

{

	struct dentry *d_percpu = tracing_dentry_percpu();

	struct dentry *entry;

	/* strlen(trace_pipe) + MAX(log10(cpu)) + '\0' */

	char filename[17];

	struct dentry *entry, *d_cpu;

	/* strlen(cpu) + MAX(log10(cpu)) + '\0' */

	char cpu_dir[7];



	if (cpu > 999 || cpu < 0)

		return;



	/* per cpu trace_pipe */

	sprintf(filename, "trace_pipe%ld", cpu);

	sprintf(cpu_dir, "cpu%ld", cpu);

	d_cpu = debugfs_create_dir(cpu_dir, d_percpu);

	if (!d_cpu) {

		pr_warning("Could not create debugfs '%s' entry\n", cpu_dir);

		return;

	}



	entry = debugfs_create_file(filename, 0444, d_percpu,

	/* per cpu trace_pipe */

	entry = debugfs_create_file("trace_pipe", 0444, d_cpu,

				(void *) cpu, &tracing_pipe_fops);

	if (!entry)

		pr_warning("Could not create debugfs '%s' entry\n", filename);

		pr_warning("Could not create debugfs 'trace_pipe' entry\n");



	/* per cpu trace */

	sprintf(filename, "trace%ld", cpu);



	entry = debugfs_create_file(filename, 0444, d_percpu,

	entry = debugfs_create_file("trace", 0444, d_cpu,

				(void *) cpu, &tracing_fops);

	if (!entry)

		pr_warning("Could not create debugfs '%s' entry\n", filename);

		pr_warning("Could not create debugfs 'trace' entry\n");

}



#ifdef CONFIG_FTRACE_SELFTEST