diff options
Diffstat (limited to 'kernel/trace/trace.c')
| -rw-r--r-- | kernel/trace/trace.c | 48 |
1 files changed, 48 insertions, 0 deletions
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 76dd0a4c8cb5..a010aba4c4a4 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -9358,6 +9358,51 @@ static const struct file_operations buffer_percent_fops = { .llseek = default_llseek, }; +static ssize_t +buffer_order_read(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos) +{ + struct trace_array *tr = filp->private_data; + char buf[64]; + int r; + + r = sprintf(buf, "%d\n", ring_buffer_subbuf_order_get(tr->array_buffer.buffer)); + + return simple_read_from_buffer(ubuf, cnt, ppos, buf, r); +} + +static ssize_t +buffer_order_write(struct file *filp, const char __user *ubuf, + size_t cnt, loff_t *ppos) +{ + struct trace_array *tr = filp->private_data; + unsigned long val; + int ret; + + ret = kstrtoul_from_user(ubuf, cnt, 10, &val); + if (ret) + return ret; + + /* limit between 1 and 128 system pages */ + if (val < 0 || val > 7) + return -EINVAL; + + ret = ring_buffer_subbuf_order_set(tr->array_buffer.buffer, val); + if (ret) + return ret; + + (*ppos)++; + + return cnt; +} + +static const struct file_operations buffer_order_fops = { + .open = tracing_open_generic_tr, + .read = buffer_order_read, + .write = buffer_order_write, + .release = tracing_release_generic_tr, + .llseek = default_llseek, +}; + static struct dentry *trace_instance_dir; static void @@ -9824,6 +9869,9 @@ init_tracer_tracefs(struct trace_array *tr, struct dentry *d_tracer) trace_create_file("buffer_percent", TRACE_MODE_WRITE, d_tracer, tr, &buffer_percent_fops); + trace_create_file("buffer_subbuf_order", TRACE_MODE_WRITE, d_tracer, + tr, &buffer_order_fops); + create_trace_options_dir(tr); #ifdef CONFIG_TRACER_MAX_TRACE |