From: "Matthew Wilcox (Oracle)" <willy@infradead.org>
To: linux-mm@kvack.org, linux-fsdevel@vger.kernel.org,
akpm@linux-foundation.org
Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>,
Zi Yan <ziy@nvidia.com>, Christoph Hellwig <hch@lst.de>,
Jeff Layton <jlayton@kernel.org>
Subject: [PATCH v8 07/31] mm: Add folio_get
Date: Fri, 30 Apr 2021 19:07:16 +0100 [thread overview]
Message-ID: <20210430180740.2707166-8-willy@infradead.org> (raw)
In-Reply-To: <20210430180740.2707166-1-willy@infradead.org>
If we know we have a folio, we can call folio_get() instead
of get_page() and save the overhead of calling compound_head().
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: Jeff Layton <jlayton@kernel.org>
---
include/linux/mm.h | 26 +++++++++++++++++---------
1 file changed, 17 insertions(+), 9 deletions(-)
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 610948f0cb43..b133734a7530 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -1219,18 +1219,26 @@ static inline bool is_pci_p2pdma_page(const struct page *page)
}
/* 127: arbitrary random number, small enough to assemble well */
-#define page_ref_zero_or_close_to_overflow(page) \
- ((unsigned int) page_ref_count(page) + 127u <= 127u)
+#define folio_ref_zero_or_close_to_overflow(folio) \
+ ((unsigned int) folio_ref_count(folio) + 127u <= 127u)
+
+/**
+ * folio_get - Increment the reference count on a folio.
+ * @folio: The folio.
+ *
+ * Context: May be called in any context, as long as you know that
+ * you have a refcount on the folio. If you do not already have one,
+ * try_grab_page() may be the right interface for you to use.
+ */
+static inline void folio_get(struct folio *folio)
+{
+ VM_BUG_ON_FOLIO(folio_ref_zero_or_close_to_overflow(folio), folio);
+ folio_ref_inc(folio);
+}
static inline void get_page(struct page *page)
{
- page = compound_head(page);
- /*
- * Getting a normal page or the head of a compound page
- * requires to already have an elevated page->_refcount.
- */
- VM_BUG_ON_PAGE(page_ref_zero_or_close_to_overflow(page), page);
- page_ref_inc(page);
+ folio_get(page_folio(page));
}
bool __must_check try_grab_page(struct page *page, unsigned int flags);
--
2.30.2
next prev parent reply other threads:[~2021-04-30 18:14 UTC|newest]
Thread overview: 41+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-30 18:07 [PATCH v8.1 00/31] Memory Folios Matthew Wilcox (Oracle)
2021-04-30 18:07 ` [PATCH v8 01/31] mm: Introduce struct folio Matthew Wilcox (Oracle)
2021-04-30 18:07 ` [PATCH v8 02/31] mm: Add folio_pgdat and folio_zone Matthew Wilcox (Oracle)
2021-04-30 18:07 ` [PATCH v8 03/31] mm/vmstat: Add functions to account folio statistics Matthew Wilcox (Oracle)
2021-04-30 18:07 ` [PATCH v8 04/31] mm/debug: Add VM_BUG_ON_FOLIO and VM_WARN_ON_ONCE_FOLIO Matthew Wilcox (Oracle)
2021-04-30 18:07 ` [PATCH v8 05/31] mm: Add folio reference count functions Matthew Wilcox (Oracle)
2021-04-30 18:07 ` [PATCH v8 06/31] mm: Add folio_put Matthew Wilcox (Oracle)
2021-04-30 18:07 ` Matthew Wilcox (Oracle) [this message]
2021-04-30 18:07 ` [PATCH v8 08/31] mm: Add folio flag manipulation functions Matthew Wilcox (Oracle)
2021-04-30 18:07 ` [PATCH v8 09/31] mm: Add folio_young() and folio_idle() Matthew Wilcox (Oracle)
2021-04-30 18:07 ` [PATCH v8 10/31] mm: Handle per-folio private data Matthew Wilcox (Oracle)
2021-04-30 18:07 ` [PATCH v8 11/31] mm/filemap: Add folio_index, folio_file_page and folio_contains Matthew Wilcox (Oracle)
2021-04-30 18:07 ` [PATCH v8 12/31] mm/filemap: Add folio_next_index Matthew Wilcox (Oracle)
2021-04-30 18:07 ` [PATCH v8 13/31] mm/filemap: Add folio_offset and folio_file_offset Matthew Wilcox (Oracle)
2021-04-30 18:07 ` [PATCH v8 14/31] mm/util: Add folio_mapping and folio_file_mapping Matthew Wilcox (Oracle)
2021-04-30 18:07 ` [PATCH v8 15/31] mm: Add folio_mapcount Matthew Wilcox (Oracle)
2021-04-30 18:07 ` [PATCH v8 16/31] mm/memcg: Add folio wrappers for various functions Matthew Wilcox (Oracle)
2021-04-30 18:07 ` [PATCH v8 17/31] mm/filemap: Add folio_unlock Matthew Wilcox (Oracle)
2021-04-30 18:07 ` [PATCH v8 18/31] mm/filemap: Add folio_lock Matthew Wilcox (Oracle)
2021-04-30 18:07 ` [PATCH v8 19/31] mm/filemap: Add folio_lock_killable Matthew Wilcox (Oracle)
2021-04-30 18:07 ` [PATCH v8 20/31] mm/filemap: Add __folio_lock_async Matthew Wilcox (Oracle)
2021-04-30 18:07 ` [PATCH v8 21/31] mm/filemap: Add __folio_lock_or_retry Matthew Wilcox (Oracle)
2021-04-30 18:07 ` [PATCH v8 22/31] mm/filemap: Add folio_wait_locked Matthew Wilcox (Oracle)
2021-04-30 18:07 ` [PATCH v8 23/31] mm/swap: Add folio_rotate_reclaimable Matthew Wilcox (Oracle)
2021-04-30 18:07 ` [PATCH v8 24/31] mm/filemap: Add folio_end_writeback Matthew Wilcox (Oracle)
2021-04-30 18:07 ` [PATCH v8 25/31] mm/writeback: Add folio_wait_writeback Matthew Wilcox (Oracle)
2021-04-30 18:07 ` [PATCH v8 26/31] mm/writeback: Add folio_wait_stable Matthew Wilcox (Oracle)
2021-04-30 18:07 ` [PATCH v8 27/31] mm/filemap: Add folio_wait_bit Matthew Wilcox (Oracle)
2021-04-30 18:07 ` [PATCH v8 28/31] mm/filemap: Add folio_wake_bit Matthew Wilcox (Oracle)
2021-04-30 18:07 ` [PATCH v8 29/31] mm/filemap: Convert page wait queues to be folios Matthew Wilcox (Oracle)
2021-04-30 18:07 ` [PATCH v8 30/31] mm/filemap: Add folio private_2 functions Matthew Wilcox (Oracle)
2021-04-30 18:07 ` [PATCH v8 31/31] fs/netfs: Add folio fscache functions Matthew Wilcox (Oracle)
2021-04-30 18:47 ` [PATCH v8.1 00/31] Memory Folios Hugh Dickins
2021-05-01 1:32 ` Nicholas Piggin
2021-05-01 2:37 ` Matthew Wilcox
2021-05-01 14:31 ` Matthew Wilcox
2021-05-01 21:38 ` John Hubbard
2021-05-02 0:17 ` Matthew Wilcox
2021-05-02 0:42 ` John Hubbard
2021-05-02 0:45 ` John Hubbard
2021-05-02 2:31 ` Matthew Wilcox
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=20210430180740.2707166-8-willy@infradead.org \
--to=willy@infradead.org \
--cc=akpm@linux-foundation.org \
--cc=hch@lst.de \
--cc=jlayton@kernel.org \
--cc=linux-fsdevel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=ziy@nvidia.com \
/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).