> > Hi. > > I've been reading through a little bit on how the scheduler > works, and I was wondering how exactly when it goes back to a > process that was pre-empted/put to sleep/interrupted in > general, does it know where to continue execution? i.e. if > the program completed X instructions before it was > interrupted- how does it know to start at X+1 ? > The important thing happens during a process switch is the change of kernel mode stack of the process ( From previous process to the next process's stack ) and the rest of the thing follows. In simple terms, a IRET instruction will cause the execution of the instruction X+1 ( when that process was last interuppted ) because CPU is now working with the next process stack. Also, one important macro is "current" ( points to the tast_struct of the running process ) which is actually derived from the stack pointer of the processor. > jnf > > -- > Kernelnewbies: Help each other learn about the Linux kernel. > Archive: http://mail.nl.linux.org/kernelnewbies/ > FAQ: http://kernelnewbies.org/faq/ > > -- Kernelnewbies: Help each other learn about the Linux kernel. Archive: http://mail.nl.linux.org/kernelnewbies/ FAQ: http://kernelnewbies.org/faq/
