On 09/26/2014 10:03 AM, Steve Capper wrote: > This series implements general forms of get_user_pages_fast and > __get_user_pages_fast in core code and activates them for arm and arm64. > > These are required for Transparent HugePages to function correctly, as > a futex on a THP tail will otherwise result in an infinite loop (due to > the core implementation of __get_user_pages_fast always returning 0). > > Unfortunately, a futex on THP tail can be quite common for certain > workloads; thus THP is unreliable without a __get_user_pages_fast > implementation. > > This series may also be beneficial for direct-IO heavy workloads and > certain KVM workloads. > > I appreciate that the merge window is coming very soon, and am posting > this revision on the off-chance that it gets the nod for 3.18. (The changes > thus far have been minimal and the feedback I've got has been mainly > positive). Head's up: these patches are currently implicated in a rare-to-trigger hang that we are seeing on an internal kernel. An extensive effort is underway to confirm whether these are the cause. Will followup. Jon. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>