[x86] Linux Kernel Interrupt Delivery Configuration: How the Linux Kernel Interacts...
summary
Kernel 6.7 example shows how Linux chooses CPUs and vectors, allocates IRQ numbers (low bound often 24), and updates IOAPIC/MSI tables so interrupts land on the chosen CPU; the gdb/crash demo reads IDT, IOAPIC routing entries and MSI vector table to prove the configuration. Request_irq uses the SP IRQ maple tree and a vector matrix that picks the CPU with the most available vectors (example picks vector 32); updates are shown applied and working.
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chapters (11)
- 0:00Interrupt delivery in Linux
- 2:11Linux kernel interrupt handling
- 4:21IDT configuration and exceptions
- 9:53Pin-based vs MSI interrupts
- 13:09Kernel interrupt structures init
- 16:47Best CPU and vector number
- 21:38MSI interrupt delivery config
- 25:15IRQ vector vs hardware IRQ
- 27:51IRQ number allocation
- 30:47Finding MSI vector number
- 32:31Updating MSI vector table
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