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-rw-r--r--kernel/trace/ring_buffer.c24
1 files changed, 18 insertions, 6 deletions
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index acbb0e73d3a2..1275175b0946 100644
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -3440,11 +3440,23 @@ EXPORT_SYMBOL_GPL(ring_buffer_iter_reset);
int ring_buffer_iter_empty(struct ring_buffer_iter *iter)
{
struct ring_buffer_per_cpu *cpu_buffer;
+ struct buffer_page *reader;
+ struct buffer_page *head_page;
+ struct buffer_page *commit_page;
+ unsigned commit;
cpu_buffer = iter->cpu_buffer;
- return iter->head_page == cpu_buffer->commit_page &&
- iter->head == rb_commit_index(cpu_buffer);
+ /* Remember, trace recording is off when iterator is in use */
+ reader = cpu_buffer->reader_page;
+ head_page = cpu_buffer->head_page;
+ commit_page = cpu_buffer->commit_page;
+ commit = rb_page_commit(commit_page);
+
+ return ((iter->head_page == commit_page && iter->head == commit) ||
+ (iter->head_page == reader && commit_page == head_page &&
+ head_page->read == commit &&
+ iter->head == rb_page_commit(cpu_buffer->reader_page)));
}
EXPORT_SYMBOL_GPL(ring_buffer_iter_empty);
@@ -4875,9 +4887,9 @@ static __init int test_ringbuffer(void)
rb_data[cpu].cnt = cpu;
rb_threads[cpu] = kthread_create(rb_test, &rb_data[cpu],
"rbtester/%d", cpu);
- if (WARN_ON(!rb_threads[cpu])) {
+ if (WARN_ON(IS_ERR(rb_threads[cpu]))) {
pr_cont("FAILED\n");
- ret = -1;
+ ret = PTR_ERR(rb_threads[cpu]);
goto out_free;
}
@@ -4887,9 +4899,9 @@ static __init int test_ringbuffer(void)
/* Now create the rb hammer! */
rb_hammer = kthread_run(rb_hammer_test, NULL, "rbhammer");
- if (WARN_ON(!rb_hammer)) {
+ if (WARN_ON(IS_ERR(rb_hammer))) {
pr_cont("FAILED\n");
- ret = -1;
+ ret = PTR_ERR(rb_hammer);
goto out_free;
}