Messages in this thread | | | Date | Wed, 18 Dec 2013 20:40:25 +0100 | From | Oleg Nesterov <> | Subject | Re: [PATCH -mm 7/7] mm: thp: introduce compound_head_put_tail(), change get_futex_key() to use it |
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On 12/18, Peter Zijlstra wrote: > > On Wed, Dec 18, 2013 at 08:20:08PM +0100, Oleg Nesterov wrote: > > +struct page *compound_head_put_tail(struct page *page) > > +{ > > + struct page *page_head; > > + unsigned long flags; > > + > > + if (!PageTail(page)) > > + return page; > > + > > + page_head = compound_trans_head(page); > > + > > + if (!__compound_tail_refcounted(page_head)) { > > This barrier is missing a comment describing the ordering and the > pairing.
Yes, and this function lacks other comments it needs, they should be copy-and-past'ed from the very similar __put_page_tail().
But I am going to unify them later if this series passes the review, can't the comments wait till then?
OTOH, I won't mind to send v2 with the additional comment about this rmb() at least. Or perhaps I should simply add /* See the comments in __put_page_tail() */ into the new helper.
OK. But I'll wait for other reviews first.
Oleg.
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