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author | Lorenzo Stoakes <lstoakes@gmail.com> | 2023-01-12 15:39:32 +0300 |
---|---|---|
committer | Andrew Morton <akpm@linux-foundation.org> | 2023-02-03 09:33:05 +0300 |
commit | a8265cd917a63c0a1e13caf07e9a0a024480372b (patch) | |
tree | fe43e11d4ab9565d752d687758975cd92cc91dfe /Documentation | |
parent | 96f97c438f61ddba94117dcd1a1eb0aaafa22309 (diff) | |
download | linux-a8265cd917a63c0a1e13caf07e9a0a024480372b.tar.xz |
Documentation/mm: update references to __m[un]lock_page() to *_folio()
We now pass folios to these functions, so update the documentation
accordingly.
Additionally, correct the outdated reference to __pagevec_lru_add_fn(),
the referenced action occurs in __munlock_folio() directly now, replace
reference to lru_cache_add_inactive_or_unevictable() with the modern folio
equivalent folio_add_lru_vma() and reference folio flags by the flag name
rather than accessor.
Link: https://lkml.kernel.org/r/898c487169d98a7f09c1c1e57a7dfdc2b3f6bf0f.1673526881.git.lstoakes@gmail.com
Signed-off-by: Lorenzo Stoakes <lstoakes@gmail.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Joel Fernandes (Google) <joel@joelfernandes.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Liam R. Howlett <Liam.Howlett@oracle.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mike Rapoport (IBM) <rppt@kernel.org>
Cc: William Kucharski <william.kucharski@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'Documentation')
-rw-r--r-- | Documentation/mm/unevictable-lru.rst | 30 |
1 files changed, 15 insertions, 15 deletions
diff --git a/Documentation/mm/unevictable-lru.rst b/Documentation/mm/unevictable-lru.rst index 4a0e158aa9ce..2a90d0721dd9 100644 --- a/Documentation/mm/unevictable-lru.rst +++ b/Documentation/mm/unevictable-lru.rst @@ -308,22 +308,22 @@ do end up getting faulted into this VM_LOCKED VMA, they will be handled in the fault path - which is also how mlock2()'s MLOCK_ONFAULT areas are handled. For each PTE (or PMD) being faulted into a VMA, the page add rmap function -calls mlock_vma_page(), which calls mlock_page() when the VMA is VM_LOCKED +calls mlock_vma_page(), which calls mlock_folio() when the VMA is VM_LOCKED (unless it is a PTE mapping of a part of a transparent huge page). Or when -it is a newly allocated anonymous page, lru_cache_add_inactive_or_unevictable() -calls mlock_new_page() instead: similar to mlock_page(), but can make better +it is a newly allocated anonymous page, folio_add_lru_vma() calls +mlock_new_folio() instead: similar to mlock_folio(), but can make better judgments, since this page is held exclusively and known not to be on LRU yet. -mlock_page() sets PageMlocked immediately, then places the page on the CPU's -mlock pagevec, to batch up the rest of the work to be done under lru_lock by -__mlock_page(). __mlock_page() sets PageUnevictable, initializes mlock_count +mlock_folio() sets PG_mlocked immediately, then places the page on the CPU's +mlock folio batch, to batch up the rest of the work to be done under lru_lock by +__mlock_folio(). __mlock_folio() sets PG_unevictable, initializes mlock_count and moves the page to unevictable state ("the unevictable LRU", but with -mlock_count in place of LRU threading). Or if the page was already PageLRU -and PageUnevictable and PageMlocked, it simply increments the mlock_count. +mlock_count in place of LRU threading). Or if the page was already PG_lru +and PG_unevictable and PG_mlocked, it simply increments the mlock_count. But in practice that may not work ideally: the page may not yet be on an LRU, or it may have been temporarily isolated from LRU. In such cases the mlock_count -field cannot be touched, but will be set to 0 later when __pagevec_lru_add_fn() +field cannot be touched, but will be set to 0 later when __munlock_folio() returns the page to "LRU". Races prohibit mlock_count from being set to 1 then: rather than risk stranding a page indefinitely as unevictable, always err with mlock_count on the low side, so that when munlocked the page will be rescued to @@ -377,8 +377,8 @@ that it is munlock() being performed. munlock_page() uses the mlock pagevec to batch up work to be done under lru_lock by __munlock_page(). __munlock_page() decrements the page's -mlock_count, and when that reaches 0 it clears PageMlocked and clears -PageUnevictable, moving the page from unevictable state to inactive LRU. +mlock_count, and when that reaches 0 it clears PG_mlocked and clears +PG_unevictable, moving the page from unevictable state to inactive LRU. But in practice that may not work ideally: the page may not yet have reached "the unevictable LRU", or it may have been temporarily isolated from it. In @@ -488,8 +488,8 @@ munlock_vma_page(), which calls munlock_page() when the VMA is VM_LOCKED munlock_page() uses the mlock pagevec to batch up work to be done under lru_lock by __munlock_page(). __munlock_page() decrements the page's -mlock_count, and when that reaches 0 it clears PageMlocked and clears -PageUnevictable, moving the page from unevictable state to inactive LRU. +mlock_count, and when that reaches 0 it clears PG_mlocked and clears +PG_unevictable, moving the page from unevictable state to inactive LRU. But in practice that may not work ideally: the page may not yet have reached "the unevictable LRU", or it may have been temporarily isolated from it. In @@ -515,7 +515,7 @@ munlocking by clearing VM_LOCKED from a VMA, before munlocking all the pages present, if one of those pages were unmapped by truncation or hole punch before mlock_pte_range() reached it, it would not be recognized as mlocked by this VMA, and would not be counted out of mlock_count. In this rare case, a page may -still appear as PageMlocked after it has been fully unmapped: and it is left to +still appear as PG_mlocked after it has been fully unmapped: and it is left to release_pages() (or __page_cache_release()) to clear it and update statistics before freeing (this event is counted in /proc/vmstat unevictable_pgs_cleared, which is usually 0). @@ -527,7 +527,7 @@ Page Reclaim in shrink_*_list() vmscan's shrink_active_list() culls any obviously unevictable pages - i.e. !page_evictable(page) pages - diverting those to the unevictable list. However, shrink_active_list() only sees unevictable pages that made it onto the -active/inactive LRU lists. Note that these pages do not have PageUnevictable +active/inactive LRU lists. Note that these pages do not have PG_unevictable set - otherwise they would be on the unevictable list and shrink_active_list() would never see them. |