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

[Esben Nielsen]

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
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/