On Wed, Sep 27, 2006 at 04:06:59PM +0200, Ingo Molnar wrote:
>
> * Eric W. Biederman <[email protected]> wrote:
>
> > I'm still wondering if we can move put_task_struct a little lower in
> > the logic in the places where it is called, so it isn't called under a
> > lock, or with preemption disabled. The only downside I see is that it
> > might convolute the logic into unreadability.
>
> well it's all a function of the task reaping logic: right now we in
> essence complete the reaping from the scheduler, via prev_state ==
> TASK_DEAD. We cannot do it sooner because the task is still in use. I
> had one other implementation upstream some time ago, which was a
> single-slot cache for reaped tasks - but that uglified other codepaths
> because _something_ has to notice that the task has been unscheduled.
I believe that we are way too far into the task-teardown process for
something like synchronize_rcu() to be feasible (not enough of the
task left to be able to sleep!), but thought I should bring up the
possibility on the off-chance that it caused someone to come up with a
better approach.
Another possible approach would be workqueues. The disadvantages here are
(1) higher overhead (2) workqueues can be delayed for a -long- time in a
realtime environment, which increases vulnerability to memory exhaustion.
Again, hoping this provokes some better ideas...
Thanx, Paul
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" 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.tux.org/lkml/
[Index of Archives]
[Kernel Newbies]
[Netfilter]
[Bugtraq]
[Photo]
[Stuff]
[Gimp]
[Yosemite News]
[MIPS Linux]
[ARM Linux]
[Linux Security]
[Linux RAID]
[Video 4 Linux]
[Linux for the blind]
[Linux Resources]
