Prepare khugepaged to see compound pages mapped with pte. For now we won't collapse the pmd table with such pte.
khugepaged is subject for future rework wrt new refcounting. Signed-off-by: Kirill A. Shutemov <[email protected]> Tested-by: Sasha Levin <[email protected]> Tested-by: Aneesh Kumar K.V <[email protected]> Acked-by: Jerome Marchand <[email protected]> Acked-by: Vlastimil Babka <[email protected]> --- include/trace/events/huge_memory.h | 1 + mm/huge_memory.c | 9 ++++++++- 2 files changed, 9 insertions(+), 1 deletion(-) diff --git a/include/trace/events/huge_memory.h b/include/trace/events/huge_memory.h index 1efc7f1dc9bd..11c59ca5e145 100644 --- a/include/trace/events/huge_memory.h +++ b/include/trace/events/huge_memory.h @@ -22,6 +22,7 @@ EM( SCAN_PAGE_LRU, "page_not_in_lru") \ EM( SCAN_PAGE_LOCK, "page_locked") \ EM( SCAN_PAGE_ANON, "page_not_anon") \ + EM( SCAN_PAGE_COMPOUND, "page_compound") \ EM( SCAN_ANY_PROCESS, "no_process_for_page") \ EM( SCAN_VMA_NULL, "vma_null") \ EM( SCAN_VMA_CHECK, "vma_check_failed") \ diff --git a/mm/huge_memory.c b/mm/huge_memory.c index c41e107bddc1..7524618a923c 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -46,6 +46,7 @@ enum scan_result { SCAN_PAGE_LRU, SCAN_PAGE_LOCK, SCAN_PAGE_ANON, + SCAN_PAGE_COMPOUND, SCAN_ANY_PROCESS, SCAN_VMA_NULL, SCAN_VMA_CHECK, @@ -2881,6 +2882,13 @@ static int khugepaged_scan_pmd(struct mm_struct *mm, result = SCAN_PAGE_NULL; goto out_unmap; } + + /* TODO: teach khugepaged to collapse THP mapped with pte */ + if (PageCompound(page)) { + result = SCAN_PAGE_COMPOUND; + goto out_unmap; + } + /* * Record which node the original page is from and save this * information to khugepaged_node_load[]. @@ -2893,7 +2901,6 @@ static int khugepaged_scan_pmd(struct mm_struct *mm, goto out_unmap; } khugepaged_node_load[node]++; - VM_BUG_ON_PAGE(PageCompound(page), page); if (!PageLRU(page)) { result = SCAN_SCAN_ABORT; goto out_unmap; -- 2.5.3 -- 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/
