The patch titled
buddy: clarify comments describing buddy merge
has been added to the -mm tree. Its filename is
buddy-clarify-comments-describing-buddy-merge.patch
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------------------------------------------------------
Subject: buddy: clarify comments describing buddy merge
From: Andy Whitcroft <apw@xxxxxxxxxxxx>
In __free_one_page(), the comment "Move the buddy up one level" appears
attached to the break and by implication when the break is taken we are
moving it up one level:
if (!page_is_buddy(page, buddy, order))
break; /* Move the buddy up one level. */
In reality the inverse is true, we break out when we can no longer merge
this page with its buddy. Looking back into pre-history (into the full
git history) it appears that these two lines accidentally got joined as
part of another change.
Move the comment down where it belongs below the if and clarify its
language.
Signed-off-by: Andy Whitcroft <apw@xxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/page_alloc.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff -puN mm/page_alloc.c~buddy-clarify-comments-describing-buddy-merge mm/page_alloc.c
--- a/mm/page_alloc.c~buddy-clarify-comments-describing-buddy-merge
+++ a/mm/page_alloc.c
@@ -441,8 +441,9 @@ static inline void __free_one_page(struc
buddy = __page_find_buddy(page, page_idx, order);
if (!page_is_buddy(page, buddy, order))
- break; /* Move the buddy up one level. */
+ break;
+ /* Our buddy is free, merge with it and move up one order. */
list_del(&buddy->lru);
zone->free_area[order].nr_free--;
rmv_page_order(buddy);
_
Patches currently in -mm which might be from apw@xxxxxxxxxxxx are
mm-add-a-basic-debugging-framework-for-memory-initialisation.patch
mm-add-a-basic-debugging-framework-for-memory-initialisation-fix.patch
mm-verify-the-page-links-and-memory-model.patch
mm-make-defensive-checks-around-pfn-values-registered-for-memory-usage.patch
mm-print-out-the-zonelists-on-request-for-manual-verification.patch
mm-move-bootmem-descriptors-definition-to-a-single-place.patch
mm-fix-free_all_bootmem_core-alignment-check.patch
mm-normalize-internal-argument-passing-of-bootmem-data.patch
mm-unexport-__alloc_bootmem_core.patch
buddy-clarify-comments-describing-buddy-merge.patch
update-checkpatchpl-to-version-019.patch
update-checkpatchpl-to-version-019-fix.patch
page-owner-tracking-leak-detector.patch
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