Provided by: bpfcc-tools_0.8.0-4_all
hardirqs - Measure hard IRQ (hard interrupt) event time. Uses Linux eBPF/bcc.
hardirqs [-h] [-T] [-N] [-C] [-d] [interval] [outputs]
This summarizes the time spent servicing hard IRQs (hard interrupts), and can show this time as either totals or histogram distributions. A system-wide summary of this time is shown by the %irq column of mpstat(1), and event counts (but not times) are shown by /proc/interrupts. WARNING: This currently uses dynamic tracing of hard interrupts. You should understand what this means before use. Try in a test environment. Future versions should switch to tracepoints. Since this uses BPF, only the root user can use this tool.
CONFIG_BPF and bcc.
-h Print usage message. -T Include timestamps on output. -N Output in nanoseconds. -C Count events only. -d Show IRQ time distribution as histograms.
Sum hard IRQ event time until Ctrl-C: # hardirqs Show hard IRQ event time as histograms: # hardirqs -d Print 1 second summaries, 10 times: # hardirqs 1 10 1 second summaries, printed in nanoseconds, with timestamps: # hardirqs -NT 1
HARDIRQ The irq action name for this hard IRQ. TOTAL_usecs Total time spent in this hard IRQ in microseconds. TOTAL_nsecs Total time spent in this hard IRQ in nanoseconds. usecs Range of microseconds for this bucket. nsecs Range of nanoseconds for this bucket. count Number of hard IRQs in this time range. distribution ASCII representation of the distribution (the count column).
This traces kernel functions and maintains in-kernel counts, which are asynchronously copied to user-space. While the rate of interrupts be very high (>1M/sec), this is a relatively efficient way to trace these events, and so the overhead is expected to be small for normal workloads, but could become noticeable for heavy workloads. Measure in a test environment before use.
This is from bcc. https://github.com/iovisor/bcc Also look in the bcc distribution for a companion _examples.txt file containing example usage, output, and commentary for this tool.
Unstable - in development.