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tracing: Make tracing_cpumask available for all instances

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Allow tracer instances to disable tracing by cpu by moving
the static global tracing_cpumask into trace_array.

Link: http://lkml.kernel.org/r/921622317f239bfc2283cac2242647801ef584f2.1375980149.git.azl@google.com

Cc: Vaibhav Nagarnaik <vnagarnaik@google.com>
Cc: David Sharp <dhsharp@google.com>
Cc: Alexander Z Lam <lambchop468@gmail.com>
Signed-off-by: Alexander Z Lam <azl@google.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
This commit is contained in:
Alexander Z Lam 2013-08-08 09:47:45 -07:00 committed by Steven Rostedt
parent 836d481ed7
commit ccfe9e42e4
2 changed files with 21 additions and 17 deletions
repo.diff.show_diff_stats Download patch file Download diff file Expand all files Collapse all files

37
kernel/trace/trace.c
View file

@ -3165,11 +3165,6 @@ static const struct file_operations show_traces_fops = {
.llseek = seq_lseek,
};
/*
* Only trace on a CPU if the bitmask is set:
*/
static cpumask_var_t tracing_cpumask;
/*
* The tracer itself will not take this lock, but still we want
* to provide a consistent cpumask to user-space:
@ -3186,11 +3181,12 @@ static ssize_t
tracing_cpumask_read(struct file *filp, char __user *ubuf,
size_t count, loff_t *ppos)
{
struct trace_array *tr = file_inode(filp)->i_private;
int len;
mutex_lock(&tracing_cpumask_update_lock);
len = cpumask_scnprintf(mask_str, count, tracing_cpumask);
len = cpumask_scnprintf(mask_str, count, tr->tracing_cpumask);
if (count - len < 2) {
count = -EINVAL;
goto out_err;
@ -3208,7 +3204,7 @@ static ssize_t
tracing_cpumask_write(struct file *filp, const char __user *ubuf,
size_t count, loff_t *ppos)
{
struct trace_array *tr = filp->private_data;
struct trace_array *tr = file_inode(filp)->i_private;
cpumask_var_t tracing_cpumask_new;
int err, cpu;
@ -3228,12 +3224,12 @@ tracing_cpumask_write(struct file *filp, const char __user *ubuf,
* Increase/decrease the disabled counter if we are
* about to flip a bit in the cpumask:
*/
if (cpumask_test_cpu(cpu, tracing_cpumask) &&
if (cpumask_test_cpu(cpu, tr->tracing_cpumask) &&
!cpumask_test_cpu(cpu, tracing_cpumask_new)) {
atomic_inc(&per_cpu_ptr(tr->trace_buffer.data, cpu)->disabled);
ring_buffer_record_disable_cpu(tr->trace_buffer.buffer, cpu);
}
if (!cpumask_test_cpu(cpu, tracing_cpumask) &&
if (!cpumask_test_cpu(cpu, tr->tracing_cpumask) &&
cpumask_test_cpu(cpu, tracing_cpumask_new)) {
atomic_dec(&per_cpu_ptr(tr->trace_buffer.data, cpu)->disabled);
ring_buffer_record_enable_cpu(tr->trace_buffer.buffer, cpu);
@ -3242,7 +3238,7 @@ tracing_cpumask_write(struct file *filp, const char __user *ubuf,
arch_spin_unlock(&ftrace_max_lock);
local_irq_enable();
cpumask_copy(tracing_cpumask, tracing_cpumask_new);
cpumask_copy(tr->tracing_cpumask, tracing_cpumask_new);
mutex_unlock(&tracing_cpumask_update_lock);
free_cpumask_var(tracing_cpumask_new);
@ -3256,9 +3252,10 @@ tracing_cpumask_write(struct file *filp, const char __user *ubuf,
}
static const struct file_operations tracing_cpumask_fops = {
.open = tracing_open_generic,
.open = tracing_open_generic_tr,
.read = tracing_cpumask_read,
.write = tracing_cpumask_write,
.release = tracing_release_generic_tr,
.llseek = generic_file_llseek,
};
@ -5938,6 +5935,11 @@ static int new_instance_create(const char *name)
if (!tr->name)
goto out_free_tr;
if (!alloc_cpumask_var(&tr->tracing_cpumask, GFP_KERNEL))
goto out_free_tr;
cpumask_copy(tr->tracing_cpumask, cpu_all_mask);
raw_spin_lock_init(&tr->start_lock);
tr->current_trace = &nop_trace;
@ -5969,6 +5971,7 @@ static int new_instance_create(const char *name)
out_free_tr:
if (tr->trace_buffer.buffer)
ring_buffer_free(tr->trace_buffer.buffer);
free_cpumask_var(tr->tracing_cpumask);
kfree(tr->name);
kfree(tr);
@ -6098,6 +6101,9 @@ init_tracer_debugfs(struct trace_array *tr, struct dentry *d_tracer)
{
int cpu;
trace_create_file("tracing_cpumask", 0644, d_tracer,
tr, &tracing_cpumask_fops);
trace_create_file("trace_options", 0644, d_tracer,
tr, &tracing_iter_fops);
@ -6147,9 +6153,6 @@ static __init int tracer_init_debugfs(void)
init_tracer_debugfs(&global_trace, d_tracer);
trace_create_file("tracing_cpumask", 0644, d_tracer,
&global_trace, &tracing_cpumask_fops);
trace_create_file("available_tracers", 0444, d_tracer,
&global_trace, &show_traces_fops);
@ -6371,7 +6374,7 @@ __init static int tracer_alloc_buffers(void)
if (!alloc_cpumask_var(&tracing_buffer_mask, GFP_KERNEL))
goto out;
if (!alloc_cpumask_var(&tracing_cpumask, GFP_KERNEL))
if (!alloc_cpumask_var(&global_trace.tracing_cpumask, GFP_KERNEL))
goto out_free_buffer_mask;
/* Only allocate trace_printk buffers if a trace_printk exists */
@ -6386,7 +6389,7 @@ __init static int tracer_alloc_buffers(void)
ring_buf_size = 1;
cpumask_copy(tracing_buffer_mask, cpu_possible_mask);
cpumask_copy(tracing_cpumask, cpu_all_mask);
cpumask_copy(global_trace.tracing_cpumask, cpu_all_mask);
raw_spin_lock_init(&global_trace.start_lock);
@ -6441,7 +6444,7 @@ __init static int tracer_alloc_buffers(void)
#ifdef CONFIG_TRACER_MAX_TRACE
free_percpu(global_trace.max_buffer.data);
#endif
free_cpumask_var(tracing_cpumask);
free_cpumask_var(global_trace.tracing_cpumask);
out_free_buffer_mask:
free_cpumask_var(tracing_buffer_mask);
out:

1
kernel/trace/trace.h
View file

@ -206,6 +206,7 @@ struct trace_array {
struct dentry *event_dir;
struct list_head systems;
struct list_head events;
cpumask_var_t tracing_cpumask; /* only trace on set CPUs */
int ref;
};