From a496696ab56917baf813dacb4f4837f1ef516c50 Mon Sep 17 00:00:00 2001 From: Yang Shi Date: Fri, 19 Apr 2019 04:17:04 +0800 Subject: [PATCH] doc: mm: migration doesn't use FOLL_SPLIT anymore When demonstrating FOLL_SPLIT in transhuge document, migration is used as an example. But, since commit 94723aafb9e7 ("mm: unclutter THP migration"), the way of THP migration is totally changed. FOLL_SPLIT is not used by migration anymore due to the change. Remove the obsolete example to avoid confusion. Cc: Michal Hocko Cc: Kirill A. Shutemov Cc: Mike Rapoport Signed-off-by: Yang Shi Reviewed-by: Zi Yan Signed-off-by: Jonathan Corbet --- Documentation/vm/transhuge.rst | 8 +------- 1 file changed, 1 insertion(+), 7 deletions(-) diff --git a/Documentation/vm/transhuge.rst b/Documentation/vm/transhuge.rst index a8cf680..8df3806 100644 --- a/Documentation/vm/transhuge.rst +++ b/Documentation/vm/transhuge.rst @@ -55,13 +55,7 @@ prevent page from being split by anyone. In case you can't handle compound pages if they're returned by follow_page, the FOLL_SPLIT bit can be specified as parameter to follow_page, so that it will split the hugepages before returning -them. Migration for example passes FOLL_SPLIT as parameter to -follow_page because it's not hugepage aware and in fact it can't work -at all on hugetlbfs (but it instead works fine on transparent -hugepages thanks to FOLL_SPLIT). migration simply can't deal with -hugepages being returned (as it's not only checking the pfn of the -page and pinning it during the copy but it pretends to migrate the -memory in regular page sizes and with regular pte/pmd mappings). +them. Graceful fallback ================= -- 2.7.4