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-rw-r--r--kernel/trace/trace.c47
-rw-r--r--kernel/trace/trace.h9
-rw-r--r--kernel/trace/trace_events.c22
3 files changed, 45 insertions, 33 deletions
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index abaaf516fcae..dd6395692ff9 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -54,12 +54,6 @@
#include "trace.h"
#include "trace_output.h"
-/*
- * On boot up, the ring buffer is set to the minimum size, so that
- * we do not waste memory on systems that are not using tracing.
- */
-bool ring_buffer_expanded;
-
#ifdef CONFIG_FTRACE_STARTUP_TEST
/*
* We need to change this state when a selftest is running.
@@ -202,7 +196,7 @@ static int __init set_cmdline_ftrace(char *str)
strscpy(bootup_tracer_buf, str, MAX_TRACER_SIZE);
default_bootup_tracer = bootup_tracer_buf;
/* We are using ftrace early, expand it */
- ring_buffer_expanded = true;
+ trace_set_ring_buffer_expanded(NULL);
return 1;
}
__setup("ftrace=", set_cmdline_ftrace);
@@ -247,7 +241,7 @@ static int __init boot_alloc_snapshot(char *str)
} else {
allocate_snapshot = true;
/* We also need the main ring buffer expanded */
- ring_buffer_expanded = true;
+ trace_set_ring_buffer_expanded(NULL);
}
return 1;
}
@@ -490,6 +484,13 @@ static struct trace_array global_trace = {
.trace_flags = TRACE_DEFAULT_FLAGS,
};
+void trace_set_ring_buffer_expanded(struct trace_array *tr)
+{
+ if (!tr)
+ tr = &global_trace;
+ tr->ring_buffer_expanded = true;
+}
+
LIST_HEAD(ftrace_trace_arrays);
int trace_array_get(struct trace_array *this_tr)
@@ -2012,7 +2013,7 @@ static int run_tracer_selftest(struct tracer *type)
#ifdef CONFIG_TRACER_MAX_TRACE
if (type->use_max_tr) {
/* If we expanded the buffers, make sure the max is expanded too */
- if (ring_buffer_expanded)
+ if (tr->ring_buffer_expanded)
ring_buffer_resize(tr->max_buffer.buffer, trace_buf_size,
RING_BUFFER_ALL_CPUS);
tr->allocated_snapshot = true;
@@ -2038,7 +2039,7 @@ static int run_tracer_selftest(struct tracer *type)
tr->allocated_snapshot = false;
/* Shrink the max buffer again */
- if (ring_buffer_expanded)
+ if (tr->ring_buffer_expanded)
ring_buffer_resize(tr->max_buffer.buffer, 1,
RING_BUFFER_ALL_CPUS);
}
@@ -3403,7 +3404,7 @@ void trace_printk_init_buffers(void)
pr_warn("**********************************************************\n");
/* Expand the buffers to set size */
- tracing_update_buffers();
+ tracing_update_buffers(&global_trace);
buffers_allocated = 1;
@@ -6374,7 +6375,7 @@ static int __tracing_resize_ring_buffer(struct trace_array *tr,
* we use the size that was given, and we can forget about
* expanding it later.
*/
- ring_buffer_expanded = true;
+ trace_set_ring_buffer_expanded(tr);
/* May be called before buffers are initialized */
if (!tr->array_buffer.buffer)
@@ -6452,6 +6453,7 @@ out:
/**
* tracing_update_buffers - used by tracing facility to expand ring buffers
+ * @tr: The tracing instance
*
* To save on memory when the tracing is never used on a system with it
* configured in. The ring buffers are set to a minimum size. But once
@@ -6460,13 +6462,13 @@ out:
*
* This function is to be called when a tracer is about to be used.
*/
-int tracing_update_buffers(void)
+int tracing_update_buffers(struct trace_array *tr)
{
int ret = 0;
mutex_lock(&trace_types_lock);
- if (!ring_buffer_expanded)
- ret = __tracing_resize_ring_buffer(&global_trace, trace_buf_size,
+ if (!tr->ring_buffer_expanded)
+ ret = __tracing_resize_ring_buffer(tr, trace_buf_size,
RING_BUFFER_ALL_CPUS);
mutex_unlock(&trace_types_lock);
@@ -6520,7 +6522,7 @@ int tracing_set_tracer(struct trace_array *tr, const char *buf)
mutex_lock(&trace_types_lock);
- if (!ring_buffer_expanded) {
+ if (!tr->ring_buffer_expanded) {
ret = __tracing_resize_ring_buffer(tr, trace_buf_size,
RING_BUFFER_ALL_CPUS);
if (ret < 0)
@@ -7192,7 +7194,7 @@ tracing_entries_read(struct file *filp, char __user *ubuf,
}
if (buf_size_same) {
- if (!ring_buffer_expanded)
+ if (!tr->ring_buffer_expanded)
r = sprintf(buf, "%lu (expanded: %lu)\n",
size >> 10,
trace_buf_size >> 10);
@@ -7249,10 +7251,10 @@ tracing_total_entries_read(struct file *filp, char __user *ubuf,
mutex_lock(&trace_types_lock);
for_each_tracing_cpu(cpu) {
size += per_cpu_ptr(tr->array_buffer.data, cpu)->entries >> 10;
- if (!ring_buffer_expanded)
+ if (!tr->ring_buffer_expanded)
expanded_size += trace_buf_size >> 10;
}
- if (ring_buffer_expanded)
+ if (tr->ring_buffer_expanded)
r = sprintf(buf, "%lu\n", size);
else
r = sprintf(buf, "%lu (expanded: %lu)\n", size, expanded_size);
@@ -7646,7 +7648,7 @@ tracing_snapshot_write(struct file *filp, const char __user *ubuf, size_t cnt,
unsigned long val;
int ret;
- ret = tracing_update_buffers();
+ ret = tracing_update_buffers(tr);
if (ret < 0)
return ret;
@@ -9550,6 +9552,9 @@ static struct trace_array *trace_array_create(const char *name)
if (allocate_trace_buffers(tr, trace_buf_size) < 0)
goto out_free_tr;
+ /* The ring buffer is defaultly expanded */
+ trace_set_ring_buffer_expanded(tr);
+
if (ftrace_allocate_ftrace_ops(tr) < 0)
goto out_free_tr;
@@ -10444,7 +10449,7 @@ __init static int tracer_alloc_buffers(void)
trace_printk_init_buffers();
/* To save memory, keep the ring buffer size to its minimum */
- if (ring_buffer_expanded)
+ if (global_trace.ring_buffer_expanded)
ring_buf_size = trace_buf_size;
else
ring_buf_size = 1;
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index 77debe53f07c..e92cb9c1292f 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -410,6 +410,11 @@ struct trace_array {
struct cond_snapshot *cond_snapshot;
#endif
struct trace_func_repeats __percpu *last_func_repeats;
+ /*
+ * On boot up, the ring buffer is set to the minimum size, so that
+ * we do not waste memory on systems that are not using tracing.
+ */
+ bool ring_buffer_expanded;
};
enum {
@@ -761,7 +766,7 @@ extern int DYN_FTRACE_TEST_NAME(void);
#define DYN_FTRACE_TEST_NAME2 trace_selftest_dynamic_test_func2
extern int DYN_FTRACE_TEST_NAME2(void);
-extern bool ring_buffer_expanded;
+extern void trace_set_ring_buffer_expanded(struct trace_array *tr);
extern bool tracing_selftest_disabled;
#ifdef CONFIG_FTRACE_STARTUP_TEST
@@ -1305,7 +1310,7 @@ static inline void trace_branch_disable(void)
#endif /* CONFIG_BRANCH_TRACER */
/* set ring buffers to default size if not already done so */
-int tracing_update_buffers(void);
+int tracing_update_buffers(struct trace_array *tr);
union trace_synth_field {
u8 as_u8;
diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c
index f49d6ddb6342..099b9b6bbdc4 100644
--- a/kernel/trace/trace_events.c
+++ b/kernel/trace/trace_events.c
@@ -1166,7 +1166,7 @@ ftrace_event_write(struct file *file, const char __user *ubuf,
if (!cnt)
return 0;
- ret = tracing_update_buffers();
+ ret = tracing_update_buffers(tr);
if (ret < 0)
return ret;
@@ -1397,18 +1397,20 @@ event_enable_write(struct file *filp, const char __user *ubuf, size_t cnt,
if (ret)
return ret;
- ret = tracing_update_buffers();
- if (ret < 0)
- return ret;
-
switch (val) {
case 0:
case 1:
ret = -ENODEV;
mutex_lock(&event_mutex);
file = event_file_data(filp);
- if (likely(file))
+ if (likely(file)) {
+ ret = tracing_update_buffers(file->tr);
+ if (ret < 0) {
+ mutex_unlock(&event_mutex);
+ return ret;
+ }
ret = ftrace_event_enable_disable(file, val);
+ }
mutex_unlock(&event_mutex);
break;
@@ -1482,7 +1484,7 @@ system_enable_write(struct file *filp, const char __user *ubuf, size_t cnt,
if (ret)
return ret;
- ret = tracing_update_buffers();
+ ret = tracing_update_buffers(dir->tr);
if (ret < 0)
return ret;
@@ -1956,7 +1958,7 @@ event_pid_write(struct file *filp, const char __user *ubuf,
if (!cnt)
return 0;
- ret = tracing_update_buffers();
+ ret = tracing_update_buffers(tr);
if (ret < 0)
return ret;
@@ -2824,7 +2826,7 @@ static __init int setup_trace_triggers(char *str)
int i;
strscpy(bootup_trigger_buf, str, COMMAND_LINE_SIZE);
- ring_buffer_expanded = true;
+ trace_set_ring_buffer_expanded(NULL);
disable_tracing_selftest("running event triggers");
buf = bootup_trigger_buf;
@@ -3614,7 +3616,7 @@ static char bootup_event_buf[COMMAND_LINE_SIZE] __initdata;
static __init int setup_trace_event(char *str)
{
strscpy(bootup_event_buf, str, COMMAND_LINE_SIZE);
- ring_buffer_expanded = true;
+ trace_set_ring_buffer_expanded(NULL);
disable_tracing_selftest("running event tracing");
return 1;