lkml.org 
[lkml]   [2002]   [Feb]   [26]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: schedule()
On Tue, 26 Feb 2002, Davide Libenzi wrote:

> On Tue, 26 Feb 2002, Richard B. Johnson wrote:
>
> > On Tue, 26 Feb 2002, Davide Libenzi wrote:
> >
> > > On Tue, 26 Feb 2002, Richard B. Johnson wrote:
> > >
> > > >
> > > >
> > > > I just read on this list that:
> > > >
> > > > while(something)
> > > > {
> > > > current->policy |= SCHED_YIELD;
> > > > schedule();
> > > > }
> > > >
> > > > Will no longer be allowed in a kernel module! If this is true, how
> > > > do I loop, waiting for a bit in a port, without wasting CPU time?
> > > >
> > > > A lot of hardware does not generate interrupts upon a condition,
> > > > there is no CPU activity that could send a wake_up_interruptible()
> > > > to something sleeping.
> > > >
> > > > For instance, I need to write data to a hardware FIFO, one long-word
> > > > at a time, but I can't just write. I have to wait for a bit to be
> > > > set or reset for each and every write. I'm going to be burning a
> > > > lot of CPU cycles if I can't schedule() while the trickle-down-effect
> > > > of the hardware is happening.
> > >
> > > What did it do yield() to you ? Doesn't it work for your case ?
> > >
> > There isn't one in 2.4.x I'll modify my drivers to use YIELD
> > and #define it depending upon version.
>
> In 2.5 yield() maps to sys_sched_yield(). You can handle it in the same
> way in your includes if version <= 2.4.
>
>

Can't find it in any header file.

Script started on Tue Feb 26 15:45:06 2002
# grep "sys_sched_yield()" /usr/src/linux/include/linux/*.h
# grep "sys_sched_yield()" /usr/src/linux/include/asm/*.h
You have new mail in /var/spool/mail/root
# exit
exit

Script done on Tue Feb 26 15:46:46 2002

I'll #define a macro and be done with it.


Cheers,
Dick Johnson

Penguin : Linux version 2.4.1 on an i686 machine (797.90 BogoMips).

111,111,111 * 111,111,111 = 12,345,678,987,654,321

-
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 13:24    [W:1.087 / U:0.004 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site