From: "Steven Rostedt (Google)" <rost...@goodmis.org>
The check for knowing if the poll should wait or not is basically the
exact same logic as rb_watermark_hit(). The only difference is that
rb_watermark_hit() also handles the !full case. But for the full case, the
logic is the same. Just call that instead of duplicating the code in
ring_buffer_poll_wait().
Signed-off-by: Steven Rostedt (Google) <rost...@goodmis.org>
---
kernel/trace/ring_buffer.c | 21 +++++++--------------
1 file changed, 7 insertions(+), 14 deletions(-)
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index adfe603a769b..857803e8cf07 100644
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -959,25 +959,18 @@ __poll_t ring_buffer_poll_wait(struct trace_buffer
*buffer, int cpu,
}
if (full) {
- unsigned long flags;
-
poll_wait(filp, &rbwork->full_waiters, poll_table);
- raw_spin_lock_irqsave(&cpu_buffer->reader_lock, flags);
- if (!cpu_buffer->shortest_full ||
- cpu_buffer->shortest_full > full)
- cpu_buffer->shortest_full = full;
- raw_spin_unlock_irqrestore(&cpu_buffer->reader_lock, flags);
- if (full_hit(buffer, cpu, full))
+ if (rb_watermark_hit(buffer, cpu, full))
return EPOLLIN | EPOLLRDNORM;
/*
* Only allow full_waiters_pending update to be seen after
- * the shortest_full is set. If the writer sees the
- * full_waiters_pending flag set, it will compare the
- * amount in the ring buffer to shortest_full. If the amount
- * in the ring buffer is greater than the shortest_full
- * percent, it will call the irq_work handler to wake up
- * this list. The irq_handler will reset shortest_full
+ * the shortest_full is set (in rb_watermark_hit). If the
+ * writer sees the full_waiters_pending flag set, it will
+ * compare the amount in the ring buffer to shortest_full.
+ * If the amount in the ring buffer is greater than the
+ * shortest_full percent, it will call the irq_work handler
+ * to wake up this list. The irq_handler will reset
shortest_full
* back to zero. That's done under the reader_lock, but
* the below smp_mb() makes sure that the update to
* full_waiters_pending doesn't leak up into the above.
--
2.43.0
