Re: [PATCH 39/41] Documentation: vm: fix spelling mistakes

From: Andrew Morton
Date: Thu Apr 28 2016 - 15:12:43 EST


On Thu, 28 Apr 2016 07:46:07 -0600 Jonathan Corbet <corbet@xxxxxxx> wrote:

> On Thu, 28 Apr 2016 07:31:43 -0600
> Jonathan Corbet <corbet@xxxxxxx> wrote:
>
> > On Mon, 25 Apr 2016 07:37:05 +0100
> > Eric Engestrom <eric@xxxxxxxxxxxx> wrote:
> >
> > > Documentation/vm/transhuge.txt | 6 +++---
> > > 1 file changed, 3 insertions(+), 3 deletions(-)
> >
> > Applied to the docs tree, thanks.
>
> Actually, I've just unapplied this one; it conflicts against changes in
> Andrew's tree and, thus, linux-next. Andrew, maybe you'd like to take it
> on top of what you have now?

Sure.

That Documentation/vm/transhuge.txt paragraph isn't in great shape so
I gave it some extra help.


From: Eric Engestrom <eric@xxxxxxxxxxxx>
Subject: Documentation: vm: fix spelling mistakes

Signed-off-by: Eric Engestrom <eric@xxxxxxxxxxxx>
Cc: Jonathan Corbet <corbet@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---

Documentation/vm/transhuge.txt | 12 ++++++------
1 file changed, 6 insertions(+), 6 deletions(-)

diff -puN Documentation/vm/transhuge.txt~documentation-vm-fix-spelling-mistakes Documentation/vm/transhuge.txt
--- a/Documentation/vm/transhuge.txt~documentation-vm-fix-spelling-mistakes
+++ a/Documentation/vm/transhuge.txt
@@ -340,7 +340,7 @@ unaffected. libhugetlbfs will also work

== 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
pmd_offset. It's trivial to make the code transparent hugepage aware
by just grepping for "pmd_offset" and adding split_huge_pmd where
@@ -414,7 +414,7 @@ tracking. The alternative is alter ->_ma
map/unmap of the whole compound page.

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.

split_huge_page internally has to distribute the refcounts in the head
@@ -432,10 +432,10 @@ page->_mapcount.
We safe against physical memory scanners too: the only legitimate way
scanner can get reference to a page is get_page_unless_zero().

-All tail pages has zero ->_refcount until atomic_add(). It prevent scanner
-from geting reference to tail page up to the point. After the atomic_add()
-we don't care about ->_refcount value. We already known how many references
-with should uncharge from head page.
+All tail pages have zero ->_refcount until atomic_add(). This prevents the
+scanner from getting a reference to the tail page up to that point. After the
+atomic_add() we don't care about the ->_refcount value. We already known how
+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
clear where reference should go after split: it will stay on head page.
_