Interrupt Descriptions

[John Baldwin]

A few folks have asked recently for the ability to add descriptive strings to 
registered interrupt handlers.  This is especially true since the advent of 
MSI with multiple interrupts per device.  I hacked up a prototype today that 
adds a new 'bus_describe_intr()' that takes the IRQ resource, the void * 
cookie returned by bus_setup_intr() and var args description and appends that 
to the interrupt name in the thread and vmstat -i info.  The current patch 
only has the MI bits and the MD bits for amd64 as well as a sample change to 
the igb(4) driver.

The patch is at http://www.FreeBSD.org/~jhb/patches/intr_describe.patch.

An example from this patch is:

> vmstat -i
interrupt                          total       rate
irq1: atkbd0                           8          0
irq4: uart0                          751          5
irq6: fdc0                             6          0
irq14: ata0                           36          0
irq20: uhci0                          20          0
irq23: uhci3 ehci0                     2          0
irq28: mpt0                         1661         11
irq256: igb0:tx 0                    880          6
irq257: igb0:rx 0                   1098          7
irq258: igb0:link                      3          0
irq259: igb1:tx 0                      1          0
irq260: igb1:rx 0                    134          0
irq261: igb1:link                      3          0

-- 
John Baldwin