Re: [PATCH 0/2] convert mmap_sem to a scalable rw_mutex

On Fri, 11 May 2007, Peter Zijlstra wrote:

I was toying with a scalable rw_mutex and found that it gives ~10% reduction in
system time on ebizzy runs (without the MADV_FREE patch).

You break priority enheritance on user space futexes! :-(

The problems is that the futex waiter have to take the mmap_sem. And as your rw_mutex isn't PI enabled you get priority inversions :-(

Esben
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