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: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
This commit is contained in:
Masami Hiramatsu 2020-01-11 01:07:16 +09:00 committed by Steven Rostedt (VMware)
parent 4f712a4d04
commit 9d15dbbde1
2 changed files with 43 additions and 13 deletions

View File

@ -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;
int cpu;
if (!alloc_cpumask_var(&tracing_cpumask_new, GFP_KERNEL))
return -ENOMEM;
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;

View File

@ -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