From 396ae57ef1ef978d1d21cdb7586ba184a3f22453 Mon Sep 17 00:00:00 2001 From: Kimberly Brown Date: Mon, 4 Feb 2019 02:13:09 -0500 Subject: Drivers: hv: vmbus: Expose counters for interrupts and full conditions Counter values for per-channel interrupts and ring buffer full conditions are useful for investigating performance. Expose counters in sysfs for 2 types of guest to host interrupts: 1) Interrupts caused by the channel's outbound ring buffer transitioning from empty to not empty 2) Interrupts caused by the channel's inbound ring buffer transitioning from full to not full while a packet is waiting for enough buffer space to become available Expose 2 counters in sysfs for the number of times that write operations encountered a full outbound ring buffer: 1) The total number of write operations that encountered a full condition 2) The number of write operations that were the first to encounter a full condition Increment the outbound full condition counters in the hv_ringbuffer_write() function because, for most drivers, a full outbound ring buffer is detected in that function. Also increment the outbound full condition counters in the set_channel_pending_send_size() function. In the hv_sock driver, a full outbound ring buffer is detected and set_channel_pending_send_size() is called before hv_ringbuffer_write() is called. I tested this patch by confirming that the sysfs files were created and observing the counter values. The values seemed to increase by a reasonable amount when the Hyper-v related drivers were in use. Signed-off-by: Kimberly Brown Reviewed-by: Michael Kelley Signed-off-by: Sasha Levin --- drivers/hv/ring_buffer.c | 14 +++++++++++++- 1 file changed, 13 insertions(+), 1 deletion(-) (limited to 'drivers/hv/ring_buffer.c') diff --git a/drivers/hv/ring_buffer.c b/drivers/hv/ring_buffer.c index 1f1a55e07733..9e8b31ccc142 100644 --- a/drivers/hv/ring_buffer.c +++ b/drivers/hv/ring_buffer.c @@ -74,8 +74,10 @@ static void hv_signal_on_write(u32 old_write, struct vmbus_channel *channel) * This is the only case we need to signal when the * ring transitions from being empty to non-empty. */ - if (old_write == READ_ONCE(rbi->ring_buffer->read_index)) + if (old_write == READ_ONCE(rbi->ring_buffer->read_index)) { + ++channel->intr_out_empty; vmbus_setevent(channel); + } } /* Get the next write location for the specified ring buffer. */ @@ -272,10 +274,19 @@ int hv_ringbuffer_write(struct vmbus_channel *channel, * is empty since the read index == write index. */ if (bytes_avail_towrite <= totalbytes_towrite) { + ++channel->out_full_total; + + if (!channel->out_full_flag) { + ++channel->out_full_first; + channel->out_full_flag = true; + } + spin_unlock_irqrestore(&outring_info->ring_lock, flags); return -EAGAIN; } + channel->out_full_flag = false; + /* Write to the ring buffer */ next_write_location = hv_get_next_write_location(outring_info); @@ -530,6 +541,7 @@ void hv_pkt_iter_close(struct vmbus_channel *channel) if (curr_write_sz <= pending_sz) return; + ++channel->intr_in_full; vmbus_setevent(channel); } EXPORT_SYMBOL_GPL(hv_pkt_iter_close); -- cgit v1.2.3