Commit 89474d50 authored by Eric Engestrom's avatar Eric Engestrom Committed by Linus Torvalds

Documentation: vm: fix spelling mistakes

Signed-off-by: default avatarEric Engestrom <eric@engestrom.ch>
Cc: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 0c9ad804
...@@ -340,7 +340,7 @@ unaffected. libhugetlbfs will also work fine as usual. ...@@ -340,7 +340,7 @@ unaffected. libhugetlbfs will also work fine as usual.
== Graceful fallback == == Graceful fallback ==
Code walking pagetables but unware about huge pmds can simply call Code walking pagetables but unaware about huge pmds can simply call
split_huge_pmd(vma, pmd, addr) where the pmd is the one returned by split_huge_pmd(vma, pmd, addr) where the pmd is the one returned by
pmd_offset. It's trivial to make the code transparent hugepage aware pmd_offset. It's trivial to make the code transparent hugepage aware
by just grepping for "pmd_offset" and adding split_huge_pmd where by just grepping for "pmd_offset" and adding split_huge_pmd where
...@@ -414,7 +414,7 @@ tracking. The alternative is alter ->_mapcount in all subpages on each ...@@ -414,7 +414,7 @@ tracking. The alternative is alter ->_mapcount in all subpages on each
map/unmap of the whole compound page. map/unmap of the whole compound page.
We set PG_double_map when a PMD of the page got split for the first time, We set PG_double_map when a PMD of the page got split for the first time,
but still have PMD mapping. The addtional references go away with last but still have PMD mapping. The additional references go away with last
compound_mapcount. compound_mapcount.
split_huge_page internally has to distribute the refcounts in the head split_huge_page internally has to distribute the refcounts in the head
...@@ -432,10 +432,10 @@ page->_mapcount. ...@@ -432,10 +432,10 @@ page->_mapcount.
We safe against physical memory scanners too: the only legitimate way We safe against physical memory scanners too: the only legitimate way
scanner can get reference to a page is get_page_unless_zero(). scanner can get reference to a page is get_page_unless_zero().
All tail pages has zero ->_refcount until atomic_add(). It prevent scanner All tail pages have zero ->_refcount until atomic_add(). This prevents the
from geting reference to tail page up to the point. After the atomic_add() scanner from getting a reference to the tail page up to that point. After the
we don't care about ->_refcount value. We already known how many references atomic_add() we don't care about the ->_refcount value. We already known how
with should uncharge from head page. many references should be uncharged from the head page.
For head page get_page_unless_zero() will succeed and we don't mind. It's For head page get_page_unless_zero() will succeed and we don't mind. It's
clear where reference should go after split: it will stay on head page. clear where reference should go after split: it will stay on head page.
......
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