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-rw-r--r--kernel/trace/ring_buffer.c8
-rw-r--r--kernel/trace/trace_events.c4
2 files changed, 8 insertions, 4 deletions
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index 431a922e5..337162e0c 100644
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -1543,7 +1543,6 @@ static void rb_tail_page_update(struct ring_buffer_per_cpu *cpu_buffer,
old_write = local_add_return(RB_WRITE_INTCNT, &next_page->write);
old_entries = local_add_return(RB_WRITE_INTCNT, &next_page->entries);
- local_inc(&cpu_buffer->pages_touched);
/*
* Just make sure we have seen our old_write and synchronize
* with any interrupts that come in.
@@ -1580,8 +1579,9 @@ static void rb_tail_page_update(struct ring_buffer_per_cpu *cpu_buffer,
*/
local_set(&next_page->page->commit, 0);
- /* Again, either we update tail_page or an interrupt does */
- (void)cmpxchg(&cpu_buffer->tail_page, tail_page, next_page);
+ /* Either we update tail_page or an interrupt does */
+ if (try_cmpxchg(&cpu_buffer->tail_page, &tail_page, next_page))
+ local_inc(&cpu_buffer->pages_touched);
}
}
@@ -4431,7 +4431,7 @@ int ring_buffer_iter_empty(struct ring_buffer_iter *iter)
cpu_buffer = iter->cpu_buffer;
reader = cpu_buffer->reader_page;
head_page = cpu_buffer->head_page;
- commit_page = cpu_buffer->commit_page;
+ commit_page = READ_ONCE(cpu_buffer->commit_page);
commit_ts = commit_page->page->time_stamp;
/*
diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c
index a6d2f99f8..24859d964 100644
--- a/kernel/trace/trace_events.c
+++ b/kernel/trace/trace_events.c
@@ -1669,6 +1669,7 @@ static int trace_format_open(struct inode *inode, struct file *file)
return 0;
}
+#ifdef CONFIG_PERF_EVENTS
static ssize_t
event_id_read(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos)
{
@@ -1683,6 +1684,7 @@ event_id_read(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos)
return simple_read_from_buffer(ubuf, cnt, ppos, buf, len);
}
+#endif
static ssize_t
event_filter_read(struct file *filp, char __user *ubuf, size_t cnt,
@@ -2127,10 +2129,12 @@ static const struct file_operations ftrace_event_format_fops = {
.release = seq_release,
};
+#ifdef CONFIG_PERF_EVENTS
static const struct file_operations ftrace_event_id_fops = {
.read = event_id_read,
.llseek = default_llseek,
};
+#endif
static const struct file_operations ftrace_event_filter_fops = {
.open = tracing_open_file_tr,