On 01/14/2016 08:16 AM, Paul E. McKenney wrote:
On Thu, Jan 14, 2016 at 12:04:45PM +0000, Will Deacon wrote:On Wed, Jan 13, 2016 at 12:58:22PM -0800, Leonid Yegoshin wrote:On 01/13/2016 12:48 PM, Peter Zijlstra wrote:On Wed, Jan 13, 2016 at 11:02:35AM -0800, Leonid Yegoshin wrote:I ask HW team about it but I have a question - has it any relationship with replacing MIPS SYNC with lightweight SYNCs (SYNC_WMB etc)?Of course. If you cannot explain the semantics of the primitives you introduce, how can we judge the patch.You missed a point - it is a question about replacement of SYNC with lightweight primitives. It is NOT a question about multithread system behavior without any SYNC. The answer on a latest Will's question lies in different area.What Will said! Yes, you can cut corners within MIPS architecture-specific code, but primitives that are used in the core kernel really do need to work as expected. Thanx, Paul
Absolutelly! Please use SYNC - right now it is not.An the only point - please use an appropriate SYNC_* barriers instead of heavy bold hammer. That stuff was design explicitly to support the requirements of Documentation/memory-barriers.txt
It is easy - just use smp_acquire instead of plain smp_mb insmp_load_acquire, at least for MIPS.
- Leonid. - Leonid. -- To unsubscribe from this list: send the line "unsubscribe linux-ia64" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
|