Re: preempt_disable() as synchronization tool
vinit dhatrak <[email protected]>
| Newsgroups | gmane.linux.newbie,gmane.linux.kernel.kernelnewbies |
|---|---|
| Message-ID | <[email protected]> |
On Sat, Oct 10, 2009 at 10:16 AM, askb <[email protected]> wrote: > >> > >> > Lastly, is it allowable to schedule / sleep immediately after a call >> > to preempt_disable()? >> >> No I guess kernel will panic with some error like , "scheduling while >> in Atomic Context". > > Sorry, I somehow missed out reading this. Can you let me know why its > not possible to schedule within preempt_disable() and preempt_enable()? > >From the code the schedule functions starts by disabling preemption? > Thanks in advance. - Anil > > Because, preempt_disable increments the preempt count and before scheduling the next task, schedule() function checks for the preempt count for the previous task. If its greater than 0 then it will throw an error "BUG: scheduling while atomic:" -Vinit -- To unsubscribe from this list: send the line "unsubscribe linux-newbie" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.linux-learn.org/faqs