lkml.org 
[lkml]   [2008]   [May]   [30]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH 3/3] 64-bit futexes: x86 support


On Fri, 30 May 2008, Ulrich Drepper wrote:
>
> +#ifdef CONFIG_X86_32
> + /* Not all 32-bit machines support 8-byte cmpxchg. We just
> + unconditionally perform a runtime check for the feature. */
> + if ((op & FUTEX_FLAG_64) && !boot_cpu_has(X86_FEATURE_CX8))
> + return -ENOSYS;
> +#endif

Also, doesn't this mean that effectively you have given up on any CPU
before the Pentium entirely?

Not that I want to take the patches _anyway_, but it seems doubly stupid.
Those things are going to be UP machines, so you could have just emulated
it with no correctness issues by disabling preemption.

Linus


\
 
 \ /
  Last update: 2008-05-31 04:29    [W:0.053 / U:1.248 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site