tracing/core: make the per cpu trace files in per cpu directories (8656e7a2) · Commits · 戴 / test

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:

Frederic 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:

Ingo Molnar <mingo@elte.hu>

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

Admin message