Why are there "<IRQ>" and "</IRQ>" in the call trace section? What does them imply?

[孙世龙 sunshilong]

Hi, list

As the subject, here is the related log:
[72873.713472] Call Trace:
[72873.713473]  <IRQ>
[72873.713474]  switch_mm_irqs_off+0x31b/0x4e0
[72873.713475]  xnarch_switch_to+0x2f/0x80
[72873.713476]  ___xnsched_run.part.74+0x154/0x480
[72873.713476]  ___xnsched_run+0x35/0x50
[72873.713477]  xnintr_irq_handler+0x346/0x4c0
[72873.713478]  ? xnintr_core_clock_handler+0x1b6/0x360
[72873.713479]  dispatch_irq_head+0x8e/0x110
[72873.713479]  ? xnintr_irq_handler+0x5/0x4c0
[72873.713481]  ? dispatch_irq_head+0x8e/0x110
[72873.713482]  __ipipe_dispatch_irq+0xd9/0x1c0
[72873.713483]  __ipipe_handle_irq+0x86/0x1e0
[72873.713483]  common_interrupt+0xf/0x2c
[72873.713484]  </IRQ>

Maybe, the later one(i.e. </IRQ>) implies there was an interrupt
request and the common_interuppt() function handler it.
Am I right?

But what about the former one(i.e. <IRQ>)?

Thank you for your attention to this matter.