The patch titled
Subject: mm: remove the total_mapcount argument from page_trans_huge_mapcount()
has been added to the -mm tree. Its filename is
mm-remove-the-total_mapcount-argument-from-page_trans_huge_mapcount.patch
This patch should soon appear at
https://ozlabs.org/~akpm/mmots/broken-out/mm-remove-the-total_mapcount-argument-from-page_trans_huge_mapcount.patch
and later at
https://ozlabs.org/~akpm/mmotm/broken-out/mm-remove-the-total_mapcount-argument-from-page_trans_huge_mapcount.patch
Before you just go and hit "reply", please:
a) Consider who else should be cc'ed
b) Prefer to cc a suitable mailing list as well
c) Ideally: find the original patch on the mailing list and do a
reply-to-all to that, adding suitable additional cc's
*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***
The -mm tree is included into linux-next and is updated
there every 3-4 working days
------------------------------------------------------
From: "Matthew Wilcox (Oracle)" <willy@xxxxxxxxxxxxx>
Subject: mm: remove the total_mapcount argument from page_trans_huge_mapcount()
All callers pass NULL, so we can stop calculating the value we would store
in it.
Link: https://lkml.kernel.org/r/20211220205943.456187-3-willy@xxxxxxxxxxxxx
Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
Reviewed-by: William Kucharski <william.kucharski@xxxxxxxxxx>
Acked-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: David Hildenbrand <david@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/linux/mm.h | 10 +++-------
include/linux/swap.h | 2 +-
mm/huge_memory.c | 30 ++++++++++--------------------
mm/swapfile.c | 2 +-
4 files changed, 15 insertions(+), 29 deletions(-)
--- a/include/linux/mm.h~mm-remove-the-total_mapcount-argument-from-page_trans_huge_mapcount
+++ a/include/linux/mm.h
@@ -799,19 +799,15 @@ static inline int page_mapcount(struct p
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
int total_mapcount(struct page *page);
-int page_trans_huge_mapcount(struct page *page, int *total_mapcount);
+int page_trans_huge_mapcount(struct page *page);
#else
static inline int total_mapcount(struct page *page)
{
return page_mapcount(page);
}
-static inline int page_trans_huge_mapcount(struct page *page,
- int *total_mapcount)
+static inline int page_trans_huge_mapcount(struct page *page)
{
- int mapcount = page_mapcount(page);
- if (total_mapcount)
- *total_mapcount = mapcount;
- return mapcount;
+ return page_mapcount(page);
}
#endif
--- a/include/linux/swap.h~mm-remove-the-total_mapcount-argument-from-page_trans_huge_mapcount
+++ a/include/linux/swap.h
@@ -681,7 +681,7 @@ static inline int swp_swapcount(swp_entr
}
#define reuse_swap_page(page) \
- (page_trans_huge_mapcount(page, NULL) == 1)
+ (page_trans_huge_mapcount(page) == 1)
static inline int try_to_free_swap(struct page *page)
{
--- a/mm/huge_memory.c~mm-remove-the-total_mapcount-argument-from-page_trans_huge_mapcount
+++ a/mm/huge_memory.c
@@ -2542,38 +2542,28 @@ int total_mapcount(struct page *page)
* need full accuracy to avoid breaking page pinning, because
* page_trans_huge_mapcount() is slower than page_mapcount().
*/
-int page_trans_huge_mapcount(struct page *page, int *total_mapcount)
+int page_trans_huge_mapcount(struct page *page)
{
- int i, ret, _total_mapcount, mapcount;
+ int i, ret;
/* hugetlbfs shouldn't call it */
VM_BUG_ON_PAGE(PageHuge(page), page);
- if (likely(!PageTransCompound(page))) {
- mapcount = atomic_read(&page->_mapcount) + 1;
- if (total_mapcount)
- *total_mapcount = mapcount;
- return mapcount;
- }
+ if (likely(!PageTransCompound(page)))
+ return atomic_read(&page->_mapcount) + 1;
page = compound_head(page);
- _total_mapcount = ret = 0;
+ ret = 0;
for (i = 0; i < thp_nr_pages(page); i++) {
- mapcount = atomic_read(&page[i]._mapcount) + 1;
+ int mapcount = atomic_read(&page[i]._mapcount) + 1;
ret = max(ret, mapcount);
- _total_mapcount += mapcount;
}
- if (PageDoubleMap(page)) {
+
+ if (PageDoubleMap(page))
ret -= 1;
- _total_mapcount -= thp_nr_pages(page);
- }
- mapcount = compound_mapcount(page);
- ret += mapcount;
- _total_mapcount += mapcount;
- if (total_mapcount)
- *total_mapcount = _total_mapcount;
- return ret;
+
+ return ret + compound_mapcount(page);
}
/* Racy check whether the huge page can be split */
--- a/mm/swapfile.c~mm-remove-the-total_mapcount-argument-from-page_trans_huge_mapcount
+++ a/mm/swapfile.c
@@ -1619,7 +1619,7 @@ static int page_trans_huge_map_swapcount
swapcount = page_swapcount(page);
if (total_swapcount)
*total_swapcount = swapcount;
- return swapcount + page_trans_huge_mapcount(page, NULL);
+ return swapcount + page_trans_huge_mapcount(page);
}
page = compound_head(page);
_
Patches currently in -mm which might be from willy@xxxxxxxxxxxxx are
mmfs-split-dump_mapping-out-from-dump_page.patch
mm-remove-last-argument-of-reuse_swap_page.patch
mm-remove-the-total_mapcount-argument-from-page_trans_huge_map_swapcount.patch
mm-remove-the-total_mapcount-argument-from-page_trans_huge_mapcount.patch
