Trace buffer size is now per-cpu, so that there are following two
patterns in resize of the buffers.
(1) resize per-cpu buffers to same given size
(2) resize per-cpu buffers to the other trace_array's buffer size
for each CPU (such as preparing the max_tr which is equivalent
to the global_trace's size)
__tracing_resize_ring_buffer() can be used for (1), and had
implemented (2) inside it for resetting the global_trace to the
original size.
(2) was also implemented in other place. So this patch assembles
them in a new function - resize_buffer_duplicate_size().
Signed-off-by: Hiraku Toyooka <hiraku.toyooka...@hitachi.com>
Cc: Steven Rostedt <rost...@goodmis.org>
Cc: Frederic Weisbecker <fweis...@gmail.com>
Cc: Ingo Molnar <mi...@redhat.com>
Cc: linux-kernel@vger.kernel.org
---
kernel/trace/trace.c | 58 +++++++++++++++++++++++++++-----------------------
1 files changed, 31 insertions(+), 27 deletions(-)
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 08acf42..d71eee1 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -3017,6 +3017,31 @@ static void set_buffer_entries(struct trace_array *tr,
unsigned long val)
tr->data[cpu]->entries = val;
}
+/* resize @tr's buffer to the size of @size_tr's entries */
+static int resize_buffer_duplicate_size(struct trace_array *tr,
+ struct trace_array *size_tr, int cpu_id)
+{
+ int cpu, ret = 0;
+
+ if (cpu_id == RING_BUFFER_ALL_CPUS) {
+ for_each_tracing_cpu(cpu) {
+ ret = ring_buffer_resize(tr->buffer,
+ size_tr->data[cpu]->entries, cpu);
+ if (ret < 0)
+ break;
+ tr->data[cpu]->entries = size_tr->data[cpu]->entries;
+ }
+ } else {
+ ret = ring_buffer_resize(tr->buffer,
+ size_tr->data[cpu_id]->entries, cpu_id);
+ if (ret == 0)
+ tr->data[cpu_id]->entries =
+ size_tr->data[cpu_id]->entries;
+ }
+
+ return ret;
+}
+
static int __tracing_resize_ring_buffer(unsigned long size, int cpu)
{
int ret;
@@ -3037,23 +3062,8 @@ static int __tracing_resize_ring_buffer(unsigned long
size, int cpu)
ret = ring_buffer_resize(max_tr.buffer, size, cpu);
if (ret < 0) {
- int r = 0;
-
- if (cpu == RING_BUFFER_ALL_CPUS) {
- int i;
- for_each_tracing_cpu(i) {
- r = ring_buffer_resize(global_trace.buffer,
- global_trace.data[i]->entries,
- i);
- if (r < 0)
- break;
- }
- } else {
- r = ring_buffer_resize(global_trace.buffer,
- global_trace.data[cpu]->entries,
- cpu);
- }
-
+ int r = resize_buffer_duplicate_size(&global_trace,
+ &global_trace, cpu);
if (r < 0) {
/*
* AARGH! We are left with different
@@ -3191,17 +3201,11 @@ static int tracing_set_tracer(const char *buf)
topts = create_trace_option_files(t);
if (t->use_max_tr) {
- int cpu;
/* we need to make per cpu buffer sizes equivalent */
- for_each_tracing_cpu(cpu) {
- ret = ring_buffer_resize(max_tr.buffer,
- global_trace.data[cpu]->entries,
- cpu);
- if (ret < 0)
- goto out;
- max_tr.data[cpu]->entries =
- global_trace.data[cpu]->entries;
- }
+ ret = resize_buffer_duplicate_size(&max_tr, &global_trace,
+ RING_BUFFER_ALL_CPUS);
+ if (ret < 0)
+ goto out;
}
if (t->init) {
--
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