The patch titled
Subject: mm/memblock: use a more appropriate order calculation when free memblock pages
has been added to the -mm tree. Its filename is
mm-memblock-use-a-more-appropriate-order-calculation-when-free-memblock-pages.patch
This patch should soon appear at
https://ozlabs.org/~akpm/mmots/broken-out/mm-memblock-use-a-more-appropriate-order-calculation-when-free-memblock-pages.patch
and later at
https://ozlabs.org/~akpm/mmotm/broken-out/mm-memblock-use-a-more-appropriate-order-calculation-when-free-memblock-pages.patch
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------------------------------------------------------
From: Hailong Liu <liu.hailong6@xxxxxxxxxx>
Subject: mm/memblock: use a more appropriate order calculation when free memblock pages
When system in the booting stage, pages span from [start, end] of a
memblock are freed to buddy in a order as large as possible (less than
MAX_ORDER) at first, then decrease gradually to a proper order(less than
end) in a loop.
However, *min(MAX_ORDER - 1UL, __ffs(start))* can not get the largest
order in some cases. Instead, *__ffs(end - start)* may be more
appropriate and meaningful.
Link: https://lkml.kernel.org/r/20201203152311.5272-1-carver4lio@xxxxxxx
Signed-off-by: Hailong Liu <liu.hailong6@xxxxxxxxxx>
Cc: Mike Rapoport <rppt@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/memblock.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/mm/memblock.c~mm-memblock-use-a-more-appropriate-order-calculation-when-free-memblock-pages
+++ a/mm/memblock.c
@@ -2010,7 +2010,7 @@ static void __init __free_pages_memory(u
int order;
while (start < end) {
- order = min(MAX_ORDER - 1UL, __ffs(start));
+ order = min(MAX_ORDER - 1UL, __ffs(end - start));
while (start + (1UL << order) > end)
order--;
_
Patches currently in -mm which might be from liu.hailong6@xxxxxxxxxx are
mm-memblock-use-a-more-appropriate-order-calculation-when-free-memblock-pages.patch
