[Nouveau] [PATCH 2/2] nouveau: Do not add most bo's to the global bo list.

[Ilia Mirkin]

On Wed, Feb 25, 2015 at 11:59 AM, Patrick Baggett
<baggett.patrick at gmail.com> wrote:
>> If code like
>>
>> x = *a;
>> pthread_mutex_lock or unlock or __memory_barrier()
>> y = *a;
>>
>> doesn't cause a to get loaded twice, then the compiler's in serious
>> trouble. Basically functions like pthread_mutex_lock imply that all
>> memory is changed to the compiler, and thus need to be reloaded.
>>
> Well, I've said before and I might be alone, but I disagree with you. The
> compiler is under no requirement to reload (*a) because a lock was changed.
> It does, but it doesn't have to. It's fine if you guys don't want to change
> it. It may never be a problem with gcc.
>
> This is the definition of pthread_mutex_lock() in glibc. There aren't any
> magic hints that this invalidates memory:
>
> extern int pthread_mutex_lock (pthread_mutex_t *__mutex)
> __THROWNL __nonnull ((1));
>
> THOWNL is attribute((nothrow)).

Hm, this is actually a little worrying. Maarten, thoughts? I would
have assumed there'd be a __attribute__((some_magic_thing)) in there.

  -ilia