lkml.org 
[lkml]   [2001]   [May]   [8]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: your mail
On Tue, May 08 2001, Richard B. Johnson wrote:
>
> To driver wizards:
>
> I have a driver which needs to wait for some hardware.
> Basically, it needs to have some code added to the run-queue
> so it can get some CPU time even though it's not being called.
>
> It needs to get some CPU time which can be "turned on" or
> "turned off" as a result of an interrupt or some external
> input from an ioctl().
>
> So I thought that the "tasklet" would be ideal. However, the
> scheduler "thinks" that a tasklet is an interrupt, so any
> attempt to sleep in the tasklet results in a kernel panic,
> "ieee scheduling in an interrupt..., BUG sched.c line 688".

Use a kernel thread? If you don't need to access user space, context
switches are very cheap.

> So, what am I supposed to do to add a piece of driver code to the
> run queue so it gets scheduled occasionally?

Several, grep for kernel_thread.

--
Jens Axboe

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2005-03-22 12:52    [W:0.066 / U:0.792 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site