Revert "futex_requeue_pi optimization"
This reverts commit d0aa7a70. It not only introduced user space visible changes to the futex syscall, it is also non-functional and there is no way to fix it proper before the 2.6.22 release. The breakage report ( http://lkml.org/lkml/2007/5/12/17 ) went unanswered, and unfortunately it turned out that the concept is not feasible at all. It violates the rtmutex semantics badly by introducing a virtual owner, which hacks around the coupling of the user-space pi_futex and the kernel internal rt_mutex representation. At the moment the only safe option is to remove it fully as it contains user-space visible changes to broken kernel code, which we do not want to expose in the 2.6.22 release. The patch reverts the original patch mostly 1:1, but contains a couple of trivial manual cleanups which were necessary due to patches, which touched the same area of code later. Verified against the glibc tests and my own PI futex tests. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Ingo Molnar <mingo@elte.hu> Acked-by: Ulrich Drepper <drepper@redhat.com> Cc: Pierre Peiffer <pierre.peiffer@bull.net> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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