Solaris Interrupts

In this post, I'll be shown you how to access irq table on a Solaris system and how to get statistics about the number of interrupts produced on Solaris. We'll use two commands intrstat and mdb.
intrstat command shows how many interrupts produced by each device and how many of them handled by each cpu on the system. "%tim" column shows the time where spend by that driver's interrupt handler on processing cpu. You can pass a parameter to intrstat and tell it to gather information in given intervals (in seconds). Following is a sample output of intrstat where it gets statistics in 5 seconds interval.

Now, after getting interrupt statistics we can now examine the irq table on Solaris system. For this job, we'll use solaris mdb (Solaris modular debugger). We can access irq table through the kernel. So, we'll pass the "-k" parameter to mdb. This will tell it to get in kernel debugging mode. mdb will use /dev/ksyms and /dev/kmem to access Solaris kernel. After running "mdb -k", type "::interrupts" command to acess irq table in Solaris system. Here is a sample output:

This table shows us which driver(s) (ISR) using which irq. Share column shows how many devices sharing the same irq. IPL gives irq priority. Type column show irq type used Fixed (legacy), MSI, IPI interprocessor interrupt (xcalls - cross call).