On Thu, 30 Jan 2025 15:14:38 -0300
Wander Lairson Costa [off-list ref] wrote:

The irq_handler_entry tracepoint includes a "name" field, which allows
for easy identification and filtering of specific IRQs. However, the
irq_handler_exit tracepoint lacks this field, making it difficult to
pair corresponding entry and exit events for analysis.

Add the "name" field to irq_handler_exit to enable consistent tracking
and correlation of IRQ entry and exit events.

I'm not sure what you mean by this.


# trace-cmd record -e irq_handl* sleep 5
# trace-cmd report

          <idle>-0     [000] d.h1.  4690.628641: irq_handler_entry:    irq=55 name=virtio5-output.0
          <idle>-0     [000] d.h1.  4690.628650: irq_handler_exit:     irq=55 ret=handled
          <idle>-0     [007] d.H1.  4690.628895: irq_handler_entry:    irq=54 name=virtio5-input.0
          <idle>-0     [007] d.H1.  4690.628900: irq_handler_exit:     irq=54 ret=handled
          <idle>-0     [000] d.h1.  4690.802977: irq_handler_entry:    irq=41 name=virtio2-req.0
          <idle>-0     [000] dNh1.  4690.803046: irq_handler_exit:     irq=41 ret=handled
          <idle>-0     [000] d.h1.  4690.813958: irq_handler_entry:    irq=41 name=virtio2-req.0
          <idle>-0     [000] dNh1.  4690.814008: irq_handler_exit:     irq=41 ret=handled
          <idle>-0     [000] d.H1.  4690.814257: irq_handler_entry:    irq=41 name=virtio2-req.0
          <idle>-0     [000] dNH1.  4690.814301: irq_handler_exit:     irq=41 ret=handled
          <idle>-0     [000] d.H1.  4690.815374: irq_handler_entry:    irq=41 name=virtio2-req.0

# cat /proc/interrupts |grep -e 55 -e 54 -e 41
 41:        462          0          0          0          0          0          0          0 PCI-MSIX-0000:04:00.0   1-edge      virtio2-req.0
 54:          0          0          0          0          0          0          0       4539 PCI-MSIX-0000:07:00.0   1-edge      virtio5-input.0
 55:       4544          0          0          0          0          0          0          0 PCI-MSIX-0000:07:00.0   2-edge      virtio5-output.0
RES:       1293       1411       1357       1307       1343       1345       1330       1315   Rescheduling interrupts

We have the names right there. Heck, I could probably write a plugin for
trace-cmd to record the interrupt names in the trace.dat file and print
them out with the events. Any analysis tool could also record that.

That's better than wasting ring buffer space for every event.

-- Steve