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author | David Hildenbrand <david@redhat.com> | 2024-04-09 22:22:46 +0300 |
---|---|---|
committer | Andrew Morton <akpm@linux-foundation.org> | 2024-05-06 03:53:28 +0300 |
commit | 46d62de7ad1286854e0c2944ad26a1c1b1a5f191 (patch) | |
tree | eddbaa7e22871aaf46b9ae318f7ccda84acf4fca | |
parent | c2e65ebc02fb60b64a1c5689fe2c6f60d0fc1626 (diff) | |
download | linux-46d62de7ad1286854e0c2944ad26a1c1b1a5f191.tar.xz |
mm/rmap: add fast-path for small folios when adding/removing/duplicating
Let's add a fast-path for small folios to all relevant rmap functions.
Note that only RMAP_LEVEL_PTE applies.
This is a preparation for tracking the mapcount of large folios in a
single value.
Link: https://lkml.kernel.org/r/20240409192301.907377-4-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Yin Fengwei <fengwei.yin@intel.com>
Cc: Chris Zankel <chris@zankel.net>
Cc: Hugh Dickins <hughd@google.com>
Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Naoya Horiguchi <nao.horiguchi@gmail.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Richard Chang <richardycc@google.com>
Cc: Rich Felker <dalias@libc.org>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Yang Shi <shy828301@gmail.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
-rw-r--r-- | include/linux/rmap.h | 13 | ||||
-rw-r--r-- | mm/rmap.c | 26 |
2 files changed, 29 insertions, 10 deletions
diff --git a/include/linux/rmap.h b/include/linux/rmap.h index 9549d78928bb..327f1ca5a487 100644 --- a/include/linux/rmap.h +++ b/include/linux/rmap.h @@ -322,6 +322,11 @@ static __always_inline void __folio_dup_file_rmap(struct folio *folio, switch (level) { case RMAP_LEVEL_PTE: + if (!folio_test_large(folio)) { + atomic_inc(&page->_mapcount); + break; + } + do { atomic_inc(&page->_mapcount); } while (page++, --nr_pages > 0); @@ -405,6 +410,14 @@ static __always_inline int __folio_try_dup_anon_rmap(struct folio *folio, if (PageAnonExclusive(page + i)) return -EBUSY; } + + if (!folio_test_large(folio)) { + if (PageAnonExclusive(page)) + ClearPageAnonExclusive(page); + atomic_inc(&page->_mapcount); + break; + } + do { if (PageAnonExclusive(page)) ClearPageAnonExclusive(page); diff --git a/mm/rmap.c b/mm/rmap.c index 56b313aa2ebf..4bde6d60db6c 100644 --- a/mm/rmap.c +++ b/mm/rmap.c @@ -1172,15 +1172,18 @@ static __always_inline unsigned int __folio_add_rmap(struct folio *folio, switch (level) { case RMAP_LEVEL_PTE: + if (!folio_test_large(folio)) { + nr = atomic_inc_and_test(&page->_mapcount); + break; + } + do { first = atomic_inc_and_test(&page->_mapcount); - if (first && folio_test_large(folio)) { + if (first) { first = atomic_inc_return_relaxed(mapped); - first = (first < ENTIRELY_MAPPED); + if (first < ENTIRELY_MAPPED) + nr++; } - - if (first) - nr++; } while (page++, --nr_pages > 0); break; case RMAP_LEVEL_PMD: @@ -1514,15 +1517,18 @@ static __always_inline void __folio_remove_rmap(struct folio *folio, switch (level) { case RMAP_LEVEL_PTE: + if (!folio_test_large(folio)) { + nr = atomic_add_negative(-1, &page->_mapcount); + break; + } + do { last = atomic_add_negative(-1, &page->_mapcount); - if (last && folio_test_large(folio)) { + if (last) { last = atomic_dec_return_relaxed(mapped); - last = (last < ENTIRELY_MAPPED); + if (last < ENTIRELY_MAPPED) + nr++; } - - if (last) - nr++; } while (page++, --nr_pages > 0); break; case RMAP_LEVEL_PMD: |