diff options
| author | Steven Rostedt (Google) <rostedt@goodmis.org> | 2024-03-12 09:19:21 -0400 |
|---|---|---|
| committer | Steven Rostedt (Google) <rostedt@goodmis.org> | 2024-03-12 12:44:07 -0400 |
| commit | e36f19a6457b2c0dfa4a7d19153ef0fda4bf5634 (patch) | |
| tree | e85c299a5f028b12a809d52f53a534cc6c753c6d /kernel | |
| parent | 8145f1c35fa648da662078efab299c4467b85ad5 (diff) | |
ring-buffer: Reuse rb_watermark_hit() for the poll logic
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().
Link: https://lore.kernel.org/linux-trace-kernel/20240312131952.802267543@goodmis.org
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/trace/ring_buffer.c | 21 |
1 files changed, 7 insertions, 14 deletions
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c index 99fdda29ce4e..8c3730a88662 100644 --- a/kernel/trace/ring_buffer.c +++ b/kernel/trace/ring_buffer.c @@ -960,25 +960,18 @@ __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. |