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| author | Muchun Song <songmuchun@bytedance.com> | 2021-09-08 04:55:55 +0200 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2021-09-08 20:50:23 +0200 |
| commit | fe3df441ef885a75a3eff5e151ead1a92266d222 (patch) | |
| tree | 9e1d1e5c4b1851cb9c825adef186380161b7638a /mm | |
| parent | mm/memory_hotplug: use helper zone_is_zone_device() to simplify the code (diff) | |
| download | linux-fe3df441ef885a75a3eff5e151ead1a92266d222.tar.xz linux-fe3df441ef885a75a3eff5e151ead1a92266d222.zip | |
mm: remove redundant compound_head() calling
There is a READ_ONCE() in the macro of compound_head(), which will prevent
compiler from optimizing the code when there are more than once calling of
it in a function. Remove the redundant calling of compound_head() from
page_to_index() and page_add_file_rmap() for better code generation.
Link: https://lkml.kernel.org/r/20210811101431.83940-1-songmuchun@bytedance.com
Signed-off-by: Muchun Song <songmuchun@bytedance.com>
Reviewed-by: David Howells <dhowells@redhat.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: William Kucharski <william.kucharski@oracle.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/rmap.c | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/mm/rmap.c b/mm/rmap.c index b9eb5c12f3fe..b2cebf35ffe7 100644 --- a/mm/rmap.c +++ b/mm/rmap.c @@ -1230,11 +1230,13 @@ void page_add_file_rmap(struct page *page, bool compound) nr_pages); } else { if (PageTransCompound(page) && page_mapping(page)) { + struct page *head = compound_head(page); + VM_WARN_ON_ONCE(!PageLocked(page)); - SetPageDoubleMap(compound_head(page)); + SetPageDoubleMap(head); if (PageMlocked(page)) - clear_page_mlock(compound_head(page)); + clear_page_mlock(head); } if (!atomic_inc_and_test(&page->_mapcount)) goto out; |