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 --- include/linux/hyperv.h | 46 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 46 insertions(+) (limited to 'include/linux/hyperv.h') diff --git a/include/linux/hyperv.h b/include/linux/hyperv.h index d5678a0fe598..64698ec8f2ac 100644 --- a/include/linux/hyperv.h +++ b/include/linux/hyperv.h @@ -751,6 +751,19 @@ struct vmbus_channel { u64 interrupts; /* Host to Guest interrupts */ u64 sig_events; /* Guest to Host events */ + /* + * Guest to host interrupts caused by the outbound ring buffer changing + * from empty to not empty. + */ + u64 intr_out_empty; + + /* + * Indicates that a full outbound ring buffer was encountered. The flag + * is set to true when a full outbound ring buffer is encountered and + * set to false when a write to the outbound ring buffer is completed. + */ + bool out_full_flag; + /* Channel callback's invoked in softirq context */ struct tasklet_struct callback_event; void (*onchannel_callback)(void *context); @@ -903,6 +916,24 @@ struct vmbus_channel { * vmbus_connection.work_queue and hang: see vmbus_process_offer(). */ struct work_struct add_channel_work; + + /* + * Guest to host interrupts caused by the inbound ring buffer changing + * from full to not full while a packet is waiting. + */ + u64 intr_in_full; + + /* + * The total number of write operations that encountered a full + * outbound ring buffer. + */ + u64 out_full_total; + + /* + * The number of write operations that were the first to encounter a + * full outbound ring buffer. + */ + u64 out_full_first; }; static inline bool is_hvsock_channel(const struct vmbus_channel *c) @@ -936,6 +967,21 @@ static inline void *get_per_channel_state(struct vmbus_channel *c) static inline void set_channel_pending_send_size(struct vmbus_channel *c, u32 size) { + unsigned long flags; + + if (size) { + spin_lock_irqsave(&c->outbound.ring_lock, flags); + ++c->out_full_total; + + if (!c->out_full_flag) { + ++c->out_full_first; + c->out_full_flag = true; + } + spin_unlock_irqrestore(&c->outbound.ring_lock, flags); + } else { + c->out_full_flag = false; + } + c->outbound.ring_buffer->pending_send_sz = size; } -- cgit v1.2.3-59-g8ed1b