Re: questions about native alpha futex implementation

From: Richard Henderson
Date: Wed Dec 17 2008 - 16:57:00 EST


Matt Turner wrote:
Hi,

Alpha uses a generic futex implementation, which causes some problems [1].

I've read through the code, and it appears as if the implementation
could be done by using the ldq_l/stq_c instructions, relatively easy I
might add. I'm definitely interested in implementing this, but first...

I have only a few questions.

1) What are the benefits of a native futex implementation, other than
fixing the glibc test failures?
2) Is there a technical reason it hasn't been implemented on Alpha?
3) Am in correct that it could be done with ldq_l/stq_c instructions?

I think all the futex stuff is 32-bits wide, so ldl_l/stl_c.
You can pretty much just copy the powerpc version, as that
platform also uses load-locked/store-conditional operations.


r~
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