On Mon, Jul 10, 2017 at 08:10:50AM -0500, Segher Boessenkool wrote:Yes. It's interrupt, traps, faults. If from is in the user space and to is in the kernel, it indicates the ring3 -> ring0 transition.
The "INT" thing has indeed been used as system call mechanism (typicallyPERF_BR_INT is triggered by instruction "int" .So your "PERF_BR_INT" is a system call?
PERF_BR_IRQ is triggered by interrupts, traps, faults (the ring 0,3
transition).
INT 80). But these days we have special purpose syscall instructions.
It could maybe be compared to the PPC "Unconditional TRAP with
immediate" where you use the immediate value as an index into a handler
vector.
And PERF_BR_IRQ is not an interrupt request (as its name suggests),It is actual interrupts, but also faults, traps and all the other
not what we call an "external interrupt" either; instead it is every
interrupt that is not a system call?
exceptions not caused by "INT" I think.