On Mon, Mar 16, 2009 at 3:54 PM, Manish Katiyar <mkatiyar@xxxxxxxxx> wrote: > 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 That could be the reason. This is also the part that I don't fully understand since the early day I learnt about Linux kernel. 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
