Displaying 4 results from an estimated 4 matches for "__global_lock1".
2016 Jan 04
2
[PATCH v2 20/32] metag: define __smp_xxx
On Thu, Dec 31, 2015 at 09:08:22PM +0200, Michael S. Tsirkin wrote:
> +#ifdef CONFIG_SMP
> +#define fence() metag_fence()
> +#else
> +#define fence() do { } while (0)
> #endif
James, it strikes me as odd that fence() is a no-op instead of a
barrier() for UP, can you verify/explain?
2016 Jan 04
2
[PATCH v2 20/32] metag: define __smp_xxx
On Thu, Dec 31, 2015 at 09:08:22PM +0200, Michael S. Tsirkin wrote:
> +#ifdef CONFIG_SMP
> +#define fence() metag_fence()
> +#else
> +#define fence() do { } while (0)
> #endif
James, it strikes me as odd that fence() is a no-op instead of a
barrier() for UP, can you verify/explain?
2016 Jan 04
1
[PATCH v2 20/32] metag: define __smp_xxx
...ent external reordering of writes before the fence on other
> threads with writes after the fence on this thread (and to prevent the
> ensuing cache-memory incoherence). It is therefore ineffective if used
> after and on the same thread as a write.
It is used along with the metag specific __global_lock1() (global
voluntary lock between hw threads) whenever a write is performed, and by
smp_mb/smp_rmb to try to catch other cases, but I've never been
confident this fixes every single corner case, since there could be
other places where multiple CPUs perform unsynchronised writes to the
same memor...
2016 Jan 04
0
[PATCH v2 20/32] metag: define __smp_xxx
On Mon, Jan 04, 2016 at 03:25:58PM +0000, James Hogan wrote:
> It is used along with the metag specific __global_lock1() (global
> voluntary lock between hw threads) whenever a write is performed, and by
> smp_mb/smp_rmb to try to catch other cases, but I've never been
> confident this fixes every single corner case, since there could be
> other places where multiple CPUs perform unsynchronised writ...