On Wed, 30 Jan 2008, Robin Holt wrote: > > Well the GRU uses follow_page() instead of get_user_pages. Performance is > > a major issue for the GRU. > > Worse, the GRU takes its TLB faults from within an interrupt so we > use follow_page to prevent going to sleep. That said, I think we > could probably use follow_page() with FOLL_GET set to accomplish the > requirements of mmu_notifier invalidate_range call. Doesn't look too > promising for hugetlb pages.
There may be no need to with the range_start/end scheme. The driver can have its own lock to make follow page secure. The lock needs to serialize the follow_page handler and the range_start/end calls as well as the invalidate_page callouts. I think that avoids the need for get_user_pages(). -- 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/
