Drivers: hv: vmbus: Expose per-channel interrupts and events counters

When investigating performance, it is useful to be able to look at
the number of host and guest events per-channel. This is equivalent
to per-device interrupt statistics.

Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/Documentation/ABI/stable/sysfs-bus-vmbus b/Documentation/ABI/stable/sysfs-bus-vmbus
index 0ebd8a1..d4077cc 100644 (file)
--- a/Documentation/ABI/stable/sysfs-bus-vmbus
+++ b/Documentation/ABI/stable/sysfs-bus-vmbus
@@ -61,39 +61,53 @@ Date:               September. 2017
 KernelVersion: 4.14
 Contact:       Stephen Hemminger <sthemmin@microsoft.com>
 Description:   Inbound channel signaling state
-Users:         Debuggig tools
+Users:         Debugging tools
 
 What:          /sys/bus/vmbus/devices/vmbus_*/channels/relid/latency
 Date:          September. 2017
 KernelVersion: 4.14
 Contact:       Stephen Hemminger <sthemmin@microsoft.com>
 Description:   Channel signaling latency
-Users:         Debuggig tools
+Users:         Debugging tools
 
 What:          /sys/bus/vmbus/devices/vmbus_*/channels/relid/out_mask
 Date:          September. 2017
 KernelVersion: 4.14
 Contact:       Stephen Hemminger <sthemmin@microsoft.com>
 Description:   Outbound channel signaling state
-Users:         Debuggig tools
+Users:         Debugging tools
 
 What:          /sys/bus/vmbus/devices/vmbus_*/channels/relid/pending
 Date:          September. 2017
 KernelVersion: 4.14
 Contact:       Stephen Hemminger <sthemmin@microsoft.com>
 Description:   Channel interrupt pending state
-Users:         Debuggig tools
+Users:         Debugging tools
 
 What:          /sys/bus/vmbus/devices/vmbus_*/channels/relid/read_avail
 Date:          September. 2017
 KernelVersion: 4.14
 Contact:       Stephen Hemminger <sthemmin@microsoft.com>
 Description:   Bytes availabble to read
-Users:         Debuggig tools
+Users:         Debugging tools
 
 What:          /sys/bus/vmbus/devices/vmbus_*/channels/relid/write_avail
 Date:          September. 2017
 KernelVersion: 4.14
 Contact:       Stephen Hemminger <sthemmin@microsoft.com>
 Description:   Bytes availabble to write
-Users:         Debuggig tools
+Users:         Debugging tools
+
+What:          /sys/bus/vmbus/devices/vmbus_*/channels/relid/events
+Date:          September. 2017
+KernelVersion: 4.14
+Contact:       Stephen Hemminger <sthemmin@microsoft.com>
+Description:   Number of times we have signaled the host
+Users:         Debugging tools
+
+What:          /sys/bus/vmbus/devices/vmbus_*/channels/relid/interrupts
+Date:          September. 2017
+KernelVersion: 4.14
+Contact:       Stephen Hemminger <sthemmin@microsoft.com>
+Description:   Number of times we have taken an interrupt (incoming)
+Users:         Debugging tools

diff --git a/drivers/hv/connection.c b/drivers/hv/connection.c
index f41901f..b06a6b7 100644 (file)
--- a/drivers/hv/connection.c
+++ b/drivers/hv/connection.c
@@ -409,6 +409,8 @@ void vmbus_set_event(struct vmbus_channel *channel)
        if (!channel->is_dedicated_interrupt)
                vmbus_send_interrupt(child_relid);
 
+       ++channel->sig_events;
+
        hv_do_fast_hypercall8(HVCALL_SIGNAL_EVENT, channel->sig_event);
 }
 EXPORT_SYMBOL_GPL(vmbus_set_event);

diff --git a/drivers/hv/vmbus_drv.c b/drivers/hv/vmbus_drv.c
index 1da8e81..bca8188 100644 (file)
--- a/drivers/hv/vmbus_drv.c
+++ b/drivers/hv/vmbus_drv.c
@@ -944,6 +944,8 @@ static void vmbus_chan_sched(struct hv_per_cpu_context *hv_cpu)
                        if (channel->rescind)
                                continue;
 
+                       ++channel->interrupts;
+
                        switch (channel->callback_mode) {
                        case HV_CALL_ISR:
                                vmbus_channel_isr(channel);
@@ -1237,6 +1239,18 @@ static ssize_t channel_latency_show(const struct vmbus_channel *channel,
 }
 VMBUS_CHAN_ATTR(latency, S_IRUGO, channel_latency_show, NULL);
 
+static ssize_t channel_interrupts_show(const struct vmbus_channel *channel, char *buf)
+{
+       return sprintf(buf, "%llu\n", channel->interrupts);
+}
+VMBUS_CHAN_ATTR(interrupts, S_IRUGO, channel_interrupts_show, NULL);
+
+static ssize_t channel_events_show(const struct vmbus_channel *channel, char *buf)
+{
+       return sprintf(buf, "%llu\n", channel->sig_events);
+}
+VMBUS_CHAN_ATTR(events, S_IRUGO, channel_events_show, NULL);
+
 static struct attribute *vmbus_chan_attrs[] = {
        &chan_attr_out_mask.attr,
        &chan_attr_in_mask.attr,
@@ -1245,6 +1259,8 @@ static struct attribute *vmbus_chan_attrs[] = {
        &chan_attr_cpu.attr,
        &chan_attr_pending.attr,
        &chan_attr_latency.attr,
+       &chan_attr_interrupts.attr,
+       &chan_attr_events.attr,
        NULL
 };
 

diff --git a/include/linux/hyperv.h b/include/linux/hyperv.h
index ea6b558..f3e97c5 100644 (file)
--- a/include/linux/hyperv.h
+++ b/include/linux/hyperv.h
@@ -719,6 +719,10 @@ struct vmbus_channel {
 
        struct vmbus_close_msg close_msg;
 
+       /* Statistics */
+       u64     interrupts;     /* Host to Guest interrupts */
+       u64     sig_events;     /* Guest to Host events */
+
        /* Channel callback's invoked in softirq context */
        struct tasklet_struct callback_event;
        void (*onchannel_callback)(void *context);