Re: test8-vmpatch performs great here!

[Rik van Riel <riel@conectiva.com.br>]

On Fri, 8 Sep 2000, deprogrammer wrote:

> The box remained somewhat interactive, but a few times during
> the tar zxvf the box would stop responding for a few seconds
> during which there would be alot of disk activity, same for the
> tar xvf.

This seems to be due to kflushd (bdflush) waking up
tasks in LIFO order ...

From fs/buffer.c:

in wakeup_bdflush()
   2435         __set_current_state(TASK_UNINTERRUPTIBLE);
   2436         add_wait_queue(&bdflush_done, &wait);
   2437 
   2438         wake_up_process(bdflush_tsk);
   2439         schedule();

(which adds our task to the front of the wait queue)

and in kflushd()
   2622                 wake_up(&bdflush_done);

(which wakes up the first task on the wait queue)

This results in LIFO ordering for the wakeup. I've
fixed this in my local tree (doing a wake_up_all()
instead) and will release a new patch after tweaking
things a bit more.

regards,

Rik
--
"What you're running that piece of shit Gnome?!?!"
       -- Miguel de Icaza, UKUUG 2000

http://www.conectiva.com/		http://www.surriel.com/

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