The patch titled
Subject: mm: add __clear_page_lru_flags() to replace page_off_lru()
has been added to the -mm tree. Its filename is
mm-add-__clear_page_lru_flags-to-replace-page_off_lru.patch
This patch should soon appear at
https://ozlabs.org/~akpm/mmots/broken-out/mm-add-__clear_page_lru_flags-to-replace-page_off_lru.patch
and later at
https://ozlabs.org/~akpm/mmotm/broken-out/mm-add-__clear_page_lru_flags-to-replace-page_off_lru.patch
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*** 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: Yu Zhao <yuzhao@xxxxxxxxxx>
Subject: mm: add __clear_page_lru_flags() to replace page_off_lru()
Similar to page_off_lru(), the new function does non-atomic clearing
of PageLRU() in addition to PageActive() and PageUnevictable(), on a
page that has no references left.
If PageActive() and PageUnevictable() are both set, refuse to clear
either and leave them to bad_page(). This is a behavior change that
is meant to help debug.
Link: https://lore.kernel.org/linux-mm/20201207220949.830352-7-yuzhao@xxxxxxxxxx/
Link: https://lkml.kernel.org/r/20210122220600.906146-7-yuzhao@xxxxxxxxxx
Signed-off-by: Yu Zhao <yuzhao@xxxxxxxxxx>
Cc: Alex Shi <alex.shi@xxxxxxxxxxxxxxxxx>
Cc: Hugh Dickins <hughd@xxxxxxxxxx>
Cc: Johannes Weiner <hannes@xxxxxxxxxxx>
Cc: Matthew Wilcox <willy@xxxxxxxxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxxxxx>
Cc: Roman Gushchin <guro@xxxxxx>
Cc: Vladimir Davydov <vdavydov.dev@xxxxxxxxx>
Cc: Vlastimil Babka <vbabka@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/linux/mm_inline.h | 28 ++++++++++------------------
mm/swap.c | 6 ++----
mm/vmscan.c | 3 +--
3 files changed, 13 insertions(+), 24 deletions(-)
--- a/include/linux/mm_inline.h~mm-add-__clear_page_lru_flags-to-replace-page_off_lru
+++ a/include/linux/mm_inline.h
@@ -61,27 +61,19 @@ static inline enum lru_list page_lru_bas
}
/**
- * page_off_lru - which LRU list was page on? clearing its lru flags.
- * @page: the page to test
- *
- * Returns the LRU list a page was on, as an index into the array of LRU
- * lists; and clears its Unevictable or Active flags, ready for freeing.
+ * __clear_page_lru_flags - clear page lru flags before releasing a page
+ * @page: the page that was on lru and now has a zero reference
*/
-static __always_inline enum lru_list page_off_lru(struct page *page)
+static __always_inline void __clear_page_lru_flags(struct page *page)
{
- enum lru_list lru;
+ __ClearPageLRU(page);
- if (PageUnevictable(page)) {
- __ClearPageUnevictable(page);
- lru = LRU_UNEVICTABLE;
- } else {
- lru = page_lru_base_type(page);
- if (PageActive(page)) {
- __ClearPageActive(page);
- lru += LRU_ACTIVE;
- }
- }
- return lru;
+ /* this shouldn't happen, so leave the flags to bad_page() */
+ if (PageActive(page) && PageUnevictable(page))
+ return;
+
+ __ClearPageActive(page);
+ __ClearPageUnevictable(page);
}
/**
--- a/mm/swap.c~mm-add-__clear_page_lru_flags-to-replace-page_off_lru
+++ a/mm/swap.c
@@ -84,9 +84,8 @@ static void __page_cache_release(struct
lruvec = lock_page_lruvec_irqsave(page, &flags);
VM_BUG_ON_PAGE(!PageLRU(page), page);
- __ClearPageLRU(page);
del_page_from_lru_list(page, lruvec);
- page_off_lru(page);
+ __clear_page_lru_flags(page);
unlock_page_lruvec_irqrestore(lruvec, flags);
}
__ClearPageWaiters(page);
@@ -911,9 +910,8 @@ void release_pages(struct page **pages,
lock_batch = 0;
VM_BUG_ON_PAGE(!PageLRU(page), page);
- __ClearPageLRU(page);
del_page_from_lru_list(page, lruvec);
- page_off_lru(page);
+ __clear_page_lru_flags(page);
}
__ClearPageWaiters(page);
--- a/mm/vmscan.c~mm-add-__clear_page_lru_flags-to-replace-page_off_lru
+++ a/mm/vmscan.c
@@ -1849,8 +1849,7 @@ static unsigned noinline_for_stack move_
SetPageLRU(page);
if (unlikely(put_page_testzero(page))) {
- __ClearPageLRU(page);
- __ClearPageActive(page);
+ __clear_page_lru_flags(page);
if (unlikely(PageCompound(page))) {
spin_unlock_irq(&lruvec->lru_lock);
_
Patches currently in -mm which might be from yuzhao@xxxxxxxxxx are
mm-swap-dont-setpageworkingset-unconditionally-during-swapin.patch
mm-use-add_page_to_lru_list.patch
mm-shuffle-lru-list-addition-and-deletion-functions.patch
mm-dont-pass-enum-lru_list-to-lru-list-addition-functions.patch
mm-dont-pass-enum-lru_list-to-trace_mm_lru_insertion.patch
mm-dont-pass-enum-lru_list-to-del_page_from_lru_list.patch
mm-add-__clear_page_lru_flags-to-replace-page_off_lru.patch
mm-vm_bug_on-lru-page-flags.patch
mm-fold-page_lru_base_type-into-its-sole-caller.patch
mm-fold-__update_lru_size-into-its-sole-caller.patch
mm-make-lruvec_lru_size-static.patch
