Re: [PATCH] futex: Set USER_DS for the futex_detect_cmpxchg() test

From: Thomas Gleixner
Date: Fri Sep 28 2018 - 16:26:59 EST


On Fri, 28 Sep 2018, Max Filippov wrote:

> On Fri, Sep 28, 2018 at 11:02 AM, Andy Lutomirski <luto@xxxxxxxxxxxxxx> wrote:
> > There may be a much nicer solution. Unless I missed something, only
> > mips and xtensa even have the possibility of cmpxchg being missing.
> > We could just make those arches supply a futex-detecting helper.
>
> In case of xtensa availability of cmpxchg is known at build time.

That makes it even simpler. Could you provide a patch which selects
CONFIG_HAVE_FUTEX_CMPXCHG for the right set of CPUs please?

Thanks,

tglx