On Wed, 2013-06-19 at 00:16 +0530, Aneesh Kumar K.V wrote: > But will that by anonymous memory ? ie, will we find them suitable for > THP allocation ?
The 4k pages themselves with 4k_PFN no, but the segment yes. A single of these will demote the whole segment, ie 256M or 1T. > > * If you find a THP in hash_page and the segment size is 4k, fault > > > > * In do_page_fault, re-check for that condition (or maybe we can make > > hash_page return a specific bit that gets ORed into the error_code into > > do_page_fault ?) and split huge pages there. > > > > But that's just an idea off the top of my mind, there might be a better > > way. Of course this needs to be tested. > > > > BTW. For the subpage protection, similarily, you need to make sure you > > properly map the entire segment as "no THP", not just the range > > passed-in by the user. > > Can you explain that more, why should the entire segment be marked no THP ? > The segment can work with 4K base page size and we still be able to > allocate a hugepage in that segment. Will we be able to track all the possible hashings of the huge page on a 4k segment ? Ben. _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
