Re: 'simple' futex interface [Was: [PATCH v3 1/4] futex: Implement mechanism to wait on any of several futexes]

From: Florian Weimer
Date: Thu Mar 05 2020 - 11:25:43 EST


* Andrà Almeida:

> Thanks everyone for the feedback around our mechanism. Are the
> performance benefits of implementing a syscall to wait on a single futex
> significant enough to maintain it instead of just using
> `sys_futex_waitv()` with `nr_waiters = 1`? If we join both cases in a
> single interface, we may even add a new member for NUMA hint in `struct
> futex_wait`.

Some seccomp user might want to verify the address, and that's easier if
it's in an argument. But that's just a rather minor aspect.

Do you propose to drop the storage requirement for the NUMA hint
next to the futex completely?

Thanks,
Florian