"Kirill A. Shutemov" <kirill@xxxxxxxxxxxxx> writes: > On Tue, May 07, 2013 at 02:22:32AM +0530, Aneesh Kumar K.V wrote: >> From: "Aneesh Kumar K.V" <aneesh.kumar@xxxxxxxxxxxxxxxxxx> >> >> For architectures like powerpc that support multiple explicit hugepage >> sizes, HPAGE_SHIFT indicate the default explicit hugepage shift. For >> THP to work the hugepage size should be same as PMD_SIZE. So use >> PMD_SHIFT directly. So move the define outside CONFIG_TRANSPARENT_HUGEPAGE >> #ifdef because we want to use these defines in generic code with >> if (pmd_trans_huge()) conditional. >> >> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@xxxxxxxxxxxxxxxxxx> >> --- >> include/linux/huge_mm.h | 10 +++------- >> 1 file changed, 3 insertions(+), 7 deletions(-) >> >> diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h >> index 528454c..cc276d2 100644 >> --- a/include/linux/huge_mm.h >> +++ b/include/linux/huge_mm.h >> @@ -58,12 +58,11 @@ extern pmd_t *page_check_address_pmd(struct page *page, >> >> #define HPAGE_PMD_ORDER (HPAGE_PMD_SHIFT-PAGE_SHIFT) >> #define HPAGE_PMD_NR (1<<HPAGE_PMD_ORDER) >> +#define HPAGE_PMD_SHIFT PMD_SHIFT > > What about: > > #ifndef HPAGE_PMD_SHIFT > #define HPAGE_PMD_SHIFT HPAGE_SHIFT > #endif > > And define HPAGE_PMD_SHIFT in arch code if HPAGE_SHIFT is not > suitable? That would work for me provided the BUILD_BUG_ON is also taken care. But is there a reason why we want to do that ? Will any value other than PMD_SHIFT work ? The below patch shows how we want to use these. To avoid those BUILD_BUG_ON I ended up doing HUGE_PAGE_SIZE and HUGE_PAGE_MASK https://lists.ozlabs.org/pipermail/linuxppc-dev/2013-April/105631.html -aneesh -- 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>