Messages in this thread | | | Subject | Re: [PATCH 5/5] futex: fix miss ordered wakeups | From | Daniel Walker <> | Date | Thu, 12 Jun 2008 06:30:02 -0700 |
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On Thu, 2008-06-12 at 10:56 +0200, Thomas Gleixner wrote: > On Wed, 11 Jun 2008, Daniel Walker wrote: > > Adds an additional function call to the sched_setscheduler to update the > > waiter position of a task if it happens to be waiting on a futex. This > > ensures that the kernel level waiter ordering is correctly maintained > > based on the changed priority of the task. > > > > I fixed the locking issue noticed by Thomas Gleixner. > > > > This doesn't address userspace at all, only the kernel level wakeups and > > kernel level ordering. > > > > The additional locking added to the futex_wait function has no visible speed > > impact, and only effects waiters which actual enter the kernel. > > The additional locking is just broken and you did not even bother to > test your changes with lockdep.
I ran it with lockdep enabled , I didn't get any warnings..
> Aside of this, these patches still add 100 lines of code to achieve > nothing - as dicussed when you previously submitted your changes. > > Please stop wasting everyone's time with that.
It achieves correct ordering of the futex waiters inside the kernel, that is in fact _something_ ..
Daniel
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