kstat_irqs_usr(9)

okay bestie 💖 we’re opening the kstat_irqs_usr(9) page from the Kernel API Manual, and it’s giving “get the interrupt stats from thread context” realness ✨

💖 NAME 💖

kstat_irqs_usr — get the statistics for an interrupt from thread context, no cap 🫶

✨ SYNOPSIS ✨

unsigned int kstat_irqs_usr (unsigned int irq );

🎀 ARGUMENTS 🎀

• irq — the interrupt number, bestie. that’s the whole arg 💅

🌸 DESCRIPTION 🌸

Returns the sum of interrupt counts on all cpus since boot for irq. literally all the counts, summed up, from boot o’clock ⭐

It uses rcu to protect the access, because a concurrent removal of an interrupt descriptor is observing an rcu grace period before delayed_free_desc/irq_kobj_release. so yeah, there’s a whole grace-period moment happening before the cleanup, and rcu is lowkey holding the door 💀✨

🦋 SEE ALSO 🦋

• Kernel file ./kernel/irq/irqdesc.c 👑
• irq_get_nr_irqs(9)
• irq_set_nr_irqs(9)
• generic_handle_irq(9)
• generic_handle_irq_safe(9)
• generic_handle_domain_irq(9)
• generic_handle_domain_nmi(9)
• generic_handle_demux_domain_irq(9)
• irq_free_descs(9)
• __irq_alloc_descs(9)
• irq_get_next_irq(9)
• kstat_irqs_cpu(9)

xoxo, your girl signing off from ./kernel/irq — October 2026 edition, still serving kstat_irqs_usr(9) realness 💅💖🎀