Messages in this thread | | | Subject | Re: [PATCH 3/3] futex: fix miss ordered wakeups | From | Daniel Walker <> | Date | Thu, 22 May 2008 22:36:27 -0700 |
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On Thu, 2008-05-22 at 22:24 -0700, Ulrich Drepper wrote: > On Thu, May 22, 2008 at 10:15 PM, Daniel Walker <dwalker@mvista.com> wrote: > > That's the problem we aren't just covering 99.99% we're trying to cover > > 100% of cases.. If we don't do it in that one case we may as well not do > > it at all. > > I have no problem with removing the other ordering. It was added > because it limited overhead. It is completely wrong to have everybody > pay for the needs for a very small minority.
I think that ordering is something companies have been wanting for a long time.. I had a lot of people asking about it, I was glad when it was added.. However, it all falls down in the one case which we don't handle.
I don't think the overhead for this is all that bad.. Consider that the worst performance case is the contended case, and this patch adds a very small amount of code. The vast majority of cases are un-contended , and it's already know to be slow in the cases which are contended.
Daniel
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