Re: lowlatency-2.2.14-B1 + 2.2.14aa7 fixes crash, but...

From: William Montgomery (william@opinicus.com)
Date: Tue Feb 29 2000 - 11:11:21 EST


On Tue, 29 Feb 2000, Benno Senoner wrote:

> On Tue, 29 Feb 2000, William Montgomery wrote:
> >> >
> > I am testing this code now. This code appears to allow a long latency
> > path. If you have 2 SCHED_FIFO tasks which are both ready to run and
> > the kernel is in this (long) free_inode loop, one task will get scheduled
> > and if it finishes quickly the other task will have to wait.
> >
> > Could you explain again what the problem is when we always allow
> > schedule?
> >
> > Wm
>
> William, can you explain please this effect more precisely ?
> What does mean "the other task will have to wait" ?
> That the other task will not be scheduled until the inode freeing is finished,
> while the other runs fine ?

Yes. Andrea has suggested that the reschedule should only be allowed once
during the free_inode loop.

> How does the old 2.2.10-lowlatencyN6B kernel react to these 2 SCHED_FIFO
> tasks ?
>

It reacts in the desired manner, however, the 2.2.10-lowlatencyN6B patch
has a bug that Andrea pointed out. If an inode is freed during a
schedule() then the patch does not properly handle that.

Wm

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