From: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
To: linux-mm@kvack.org, Andrew Morton <akpm@linux-foundation.org>,
linux-kernel@vger.kernel.org
Cc: Michal Hocko <mhocko@suse.com>,
Linus Torvalds <torvalds@linux-foundation.org>,
"Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>,
Nicholas Piggin <npiggin@gmail.com>
Subject: [PATCH v3 1/2] mm/page_ref: use atomic_set_release in page_ref_unfreeze
Date: Mon, 12 Feb 2018 16:58:50 +0300 [thread overview]
Message-ID: <151844393004.210639.4672319312617954272.stgit@buzz> (raw)
In-Reply-To: <4f64569f-b8ce-54f8-33d9-0e67216bb54c@yandex-team.ru>
page_ref_unfreeze() has exactly that semantic. No functional
changes: just minus one barrier and proper handling of PPro errata.
Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
---
include/linux/page_ref.h | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/include/linux/page_ref.h b/include/linux/page_ref.h
index 760d74a0e9a9..14d14beb1f7f 100644
--- a/include/linux/page_ref.h
+++ b/include/linux/page_ref.h
@@ -175,8 +175,7 @@ static inline void page_ref_unfreeze(struct page *page, int count)
VM_BUG_ON_PAGE(page_count(page) != 0, page);
VM_BUG_ON(count == 0);
- smp_mb();
- atomic_set(&page->_refcount, count);
+ atomic_set_release(&page->_refcount, count);
if (page_ref_tracepoint_active(__tracepoint_page_ref_unfreeze))
__page_ref_unfreeze(page, count);
}
next prev parent reply other threads:[~2018-02-12 13:58 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-02-11 10:35 [PATCH] mm/huge_memory.c: split should clone page flags before unfreezing pageref Konstantin Khlebnikov
2018-02-11 11:07 ` Kirill A. Shutemov
2018-02-11 13:13 ` Konstantin Khlebnikov
2018-02-11 14:29 ` [PATCH v2] mm/huge_memory.c: reorder operations in __split_huge_page_tail() Konstantin Khlebnikov
2018-02-11 15:14 ` Kirill A. Shutemov
2018-02-11 15:32 ` Konstantin Khlebnikov
2018-02-11 15:47 ` Kirill A. Shutemov
2018-02-11 15:55 ` Konstantin Khlebnikov
2018-02-11 20:09 ` Matthew Wilcox
2018-02-12 13:58 ` Konstantin Khlebnikov [this message]
2018-02-12 14:07 ` [PATCH v3 1/2] mm/page_ref: use atomic_set_release in page_ref_unfreeze Kirill A. Shutemov
2018-02-12 13:58 ` [PATCH v3 2/2] mm/huge_memory.c: reorder operations in __split_huge_page_tail() Konstantin Khlebnikov
2018-02-12 14:11 ` Kirill A. Shutemov
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=151844393004.210639.4672319312617954272.stgit@buzz \
--to=khlebnikov@yandex-team.ru \
--cc=akpm@linux-foundation.org \
--cc=kirill.shutemov@linux.intel.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=mhocko@suse.com \
--cc=npiggin@gmail.com \
--cc=torvalds@linux-foundation.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).