On Mon, Mar 16, 2009 at 2:20 PM, Mulyadi Santosa <mulyadi.santosa@xxxxxxxxx> wrote: > On Sat, Mar 14, 2009 at 5:35 PM, Gaurav Tewari <gaurav6969@xxxxxxxxx> wrote: >> Hi all, >> linux switch_to function which actually does the context switch, very >> smartly preserves the 'last' field of prev task_struct across context switch >> (the third argument of switch_to()), but where and how does it uses that >> argument...or saved value... > > Understanding The Linux Kernel 3rd edition completely describe it in > the "process switching" section. It has something to do with stack > juggling.... IIRC it does so, for example when process A goes to B, > and when B want to goes back A, the pointer is already saved > > That's all I could recall this moment...CMIIW people Is it because we manipulate the stack to save the instruction of the next process at the old eip (returning address), so that when the stack unwinds it will try to execute the return address and since we have the instruction on next process there we switch tasks Thanks - Manish > > regards, > > Mulyadi. > > -- > To unsubscribe from this list: send an email with > "unsubscribe kernelnewbies" to ecartis@xxxxxxxxxxxx > Please read the FAQ at http://kernelnewbies.org/FAQ > > -- To unsubscribe from this list: send an email with "unsubscribe kernelnewbies" to ecartis@xxxxxxxxxxxx Please read the FAQ at http://kernelnewbies.org/FAQ
