On 04/17/2014 11:51 AM, Peter Zijlstra wrote:
On Thu, Apr 17, 2014 at 11:03:57AM -0400, Waiman Long wrote:
@@ -48,6 +53,9 @@
* We can further change the first spinner to spin on a bit in the lock word
* instead of its node; whereby avoiding the need to carry a node from lock to
* unlock, and preserving API.
+ *
+ * N.B. The current implementation only supports architectures that allow
+ * atomic operations on smaller 8-bit and 16-bit data types.
*/
Only for the _Q_PENDING_BITS == 8 case, the other case should still be
fine.
Yes, but _Q_PENDING_BITS is controlled by NR_CPUS which, for almost all
the distributions, is less than 16K which means _Q_PENDING_BITS will
always be set to 8, especially for non-x86 architectures.
-Longman
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