On Fri, Jun 25, 2004 at 17:20:44 +0530, Dhiman, Gaurav wrote: > Can you tell us, how the retuirn code of interrupt identifies if the > control is returning to kernel space or user space. I mean how it comes > to know that interrupt occurred in kernel space or user space. What > exactly the returning code on any interrupt checks for this. I have never studied it. I know (and have just checked that within source), that it really happens in /arch/*/kernel/entry.S. I'll leave making sense of the assembly to someone who knows it better. However, there are two occurences of "call schedule" instructions in /arch/i386/kernel/entry.S. I believe one of them is call to schedule when interrupt is returning (and need_resched is true) and the other is similar call during syscall return. ------------------------------------------------------------------------------- Jan 'Bulb' Hudec <bulb@ucw.cz>
Attachment:
signature.asc
Description: Digital signature
