Commits
Aneesh Kumar K.V committed 074c2eae3e9
powerpc/THP: Implement transparent hugepages for ppc64 We now have pmd entries covering 16MB range and the PMD table double its original size. We use the second half of the PMD table to deposit the pgtable (PTE page). The depoisted PTE page is further used to track the HPTE information. The information include [ secondary group | 3 bit hidx | valid ]. We use one byte per each HPTE entry. With 16MB hugepage and 64K HPTE we need 256 entries and with 4K HPTE we need 4096 entries. Both will fit in a 4K PTE page. On hugepage invalidate we need to walk the PTE page and invalidate all valid HPTEs. This patch implements necessary arch specific functions for THP support and also hugepage invalidate logic. These PMD related functions are intentionally kept similar to their PTE counter-part. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>