Commit 9d15dbbd authored by Masami Hiramatsu's avatar Masami Hiramatsu Committed by Steven Rostedt (VMware)
Browse files

tracing/boot: Add cpu_mask option support 

Add ftrace.cpumask option support to boot-time tracing.
This sets cpumask for each instance.

 - ftrace.[instance.INSTANCE.]cpumask = CPUMASK;
   Set the trace cpumask. Note that the CPUMASK should be a string
   which <tracefs>/tracing_cpumask can accepts.

Link: http://lkml.kernel.org/r/157867243625.17873.13613922641273149372.stgit@devnote2



Signed-off-by: default avatarMasami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: default avatarSteven Rostedt (VMware) <rostedt@goodmis.org>
parent 4f712a4d

kernel/trace/trace.c

+29 −13
Original line number Diff line number Diff line
@@ -4561,20 +4561,13 @@ tracing_cpumask_read(struct file *filp, char __user *ubuf, 
	return count;

}



static ssize_t

tracing_cpumask_write(struct file *filp, const char __user *ubuf,

		      size_t count, loff_t *ppos)

int tracing_set_cpumask(struct trace_array *tr,

			cpumask_var_t tracing_cpumask_new)

{

	struct trace_array *tr = file_inode(filp)->i_private;

	cpumask_var_t tracing_cpumask_new;

	int err, cpu;



	if (!alloc_cpumask_var(&tracing_cpumask_new, GFP_KERNEL))

		return -ENOMEM;

	int cpu;



	err = cpumask_parse_user(ubuf, count, tracing_cpumask_new);

	if (err)

		goto err_unlock;

	if (!tr)

		return -EINVAL;



	local_irq_disable();

	arch_spin_lock(&tr->max_lock);
@@ -4598,11 +4591,34 @@ tracing_cpumask_write(struct file *filp, const char __user *ubuf, 
	local_irq_enable();



	cpumask_copy(tr->tracing_cpumask, tracing_cpumask_new);



	return 0;

}



static ssize_t

tracing_cpumask_write(struct file *filp, const char __user *ubuf,

		      size_t count, loff_t *ppos)

{

	struct trace_array *tr = file_inode(filp)->i_private;

	cpumask_var_t tracing_cpumask_new;

	int err;



	if (!alloc_cpumask_var(&tracing_cpumask_new, GFP_KERNEL))

		return -ENOMEM;



	err = cpumask_parse_user(ubuf, count, tracing_cpumask_new);

	if (err)

		goto err_free;



	err = tracing_set_cpumask(tr, tracing_cpumask_new);

	if (err)

		goto err_free;



	free_cpumask_var(tracing_cpumask_new);



	return count;



err_unlock:

err_free:

	free_cpumask_var(tracing_cpumask_new);



	return err;

kernel/trace/trace_boot.c

+14 −0
Original line number Diff line number Diff line
@@ -18,6 +18,8 @@ extern int trace_set_options(struct trace_array *tr, char *option); 
extern int tracing_set_tracer(struct trace_array *tr, const char *buf);

extern ssize_t tracing_resize_ring_buffer(struct trace_array *tr,

					  unsigned long size, int cpu_id);

extern int tracing_set_cpumask(struct trace_array *tr,

				cpumask_var_t tracing_cpumask_new);



static void __init

trace_boot_set_instance_options(struct trace_array *tr, struct xbc_node *node)
@@ -52,6 +54,18 @@ trace_boot_set_instance_options(struct trace_array *tr, struct xbc_node *node) 
		if (tracing_resize_ring_buffer(tr, v, RING_BUFFER_ALL_CPUS) < 0)

			pr_err("Failed to resize trace buffer to %s\n", p);

	}



	p = xbc_node_find_value(node, "cpumask", NULL);

	if (p && *p != '\0') {

		cpumask_var_t new_mask;



		if (alloc_cpumask_var(&new_mask, GFP_KERNEL)) {

			if (cpumask_parse(p, new_mask) < 0 ||

			    tracing_set_cpumask(tr, new_mask) < 0)

				pr_err("Failed to set new CPU mask %s\n", p);

			free_cpumask_var(new_mask);

		}

	}

}



#ifdef CONFIG_EVENT_TRACING