Hi, in order to implement TLB flushing on s390 in a way that is 100% compliant with the architecture I would like to introcude a new hook to the scheduler. In concept it pairs with the switch_mm function and is called after all locks have been released to complete the switch_mm operation. The use case for s390 boils down to the ability to wait for another CPU in switch_mm/ finish_switch_mm.
Right now the issue is theoretical and can only show up under a extreme race condition in combination with a buggy user space program. But to implement local TLB flushing which has been added to the latest machine (zEC12) the finish_switch_mm hook will be needed. Patch #2 of the series is included as reference and shows how the finish_switch_mm hook would be used in s390 code. The description of the patch has more details why the hook is needed. -- 1.7.9.5 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
