Re: [PATCH] docs: update THP documentation to clarify sysfs "never" setting
From: Baolin Wang <baolin.wang@linux.alibaba.com>
Date: 2025-07-22 05:59:51
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linux-mm, lkml
On 2025/7/22 13:34, Lorenzo Stoakes wrote:
Hi Andrew, Could you apply this fix-patch? It adds the caveat regarding MADV_COLLAPSE in a couple other places whwere the sysfs 'never' mode is mentioned. Thanks, Lorenzo ----8<---- From 7c0bdda6a633bc38e7d5a3b0acf2cef7bdc961af Mon Sep 17 00:00:00 2001 From: Lorenzo Stoakes <redacted> Date: Tue, 22 Jul 2025 06:32:18 +0100 Subject: [PATCH] docs: update admin guide transhuge page to mention MADV_COLLAPSE everywhere We previously missed a couple places where the 'never' mode was described, put the caveat regarding MADV_COLLAPSE in these locations also. Signed-off-by: Lorenzo Stoakes <redacted>
Thanks. Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com>
quoted hunk ↗ jump to hunk
--- Documentation/admin-guide/mm/transhuge.rst | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-)diff --git a/Documentation/admin-guide/mm/transhuge.rst b/Documentation/admin-guide/mm/transhuge.rst index 182519197ef7..370fba113460 100644 --- a/Documentation/admin-guide/mm/transhuge.rst +++ b/Documentation/admin-guide/mm/transhuge.rst@@ -385,7 +385,9 @@ always Attempt to allocate huge pages every time we need a new page; never - Do not allocate huge pages; + Do not allocate huge pages. Note that ``madvise(..., MADV_COLLAPSE)`` + can still cause transparent huge pages to be obtained even if this mode + is specified everywhere; within_size Only allocate huge page if it will be fully within i_size.@@ -441,7 +443,9 @@ inherit have enabled="inherit" and all other hugepage sizes have enabled="never"; never - Do not allocate <size> huge pages; + Do not allocate <size> huge pages. Note that ``madvise(..., + MADV_COLLAPSE)`` can still cause transparent huge pages to be obtained + even if this mode is specified everywhere; within_size Only allocate <size> huge page if it will be fully within i_size. --2.50.1