From: "Matthew Wilcox (Oracle)" <willy@infradead.org>
To: linux-fsdevel@vger.kernel.org, linux-mm@kvack.org
Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>,
akpm@linux-foundation.org, hughd@google.com, hch@lst.de,
hannes@cmpxchg.org, yang.shi@linux.alibaba.com,
dchinner@redhat.com, linux-kernel@vger.kernel.org
Subject: [PATCH v4 04/16] mm: Add FGP_ENTRY
Date: Thu, 12 Nov 2020 21:26:29 +0000 [thread overview]
Message-ID: <20201112212641.27837-5-willy@infradead.org> (raw)
In-Reply-To: <20201112212641.27837-1-willy@infradead.org>
The functionality of find_lock_entry() and find_get_entry() can be
provided by pagecache_get_pages(), which lets us delete find_lock_entry()
and make find_get_entry() static.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
---
include/linux/pagemap.h | 1 +
mm/filemap.c | 44 ++++++++---------------------------------
mm/internal.h | 3 ---
mm/shmem.c | 3 ++-
mm/swap_state.c | 3 ++-
5 files changed, 13 insertions(+), 41 deletions(-)
diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h
index edb990f3b930..55e1bff1c4b9 100644
--- a/include/linux/pagemap.h
+++ b/include/linux/pagemap.h
@@ -313,6 +313,7 @@ pgoff_t page_cache_prev_miss(struct address_space *mapping,
#define FGP_NOWAIT 0x00000020
#define FGP_FOR_MMAP 0x00000040
#define FGP_HEAD 0x00000080
+#define FGP_ENTRY 0x00000100
struct page *pagecache_get_page(struct address_space *mapping, pgoff_t offset,
int fgp_flags, gfp_t cache_gfp_mask);
diff --git a/mm/filemap.c b/mm/filemap.c
index bb6f2ae5a68c..01603f021740 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -1662,7 +1662,7 @@ pgoff_t page_cache_prev_miss(struct address_space *mapping,
}
EXPORT_SYMBOL(page_cache_prev_miss);
-/**
+/*
* find_get_entry - find and get a page cache entry
* @mapping: the address_space to search
* @index: The page cache index.
@@ -1675,7 +1675,7 @@ EXPORT_SYMBOL(page_cache_prev_miss);
*
* Return: The head page or shadow entry, %NULL if nothing is found.
*/
-struct page *find_get_entry(struct address_space *mapping, pgoff_t index)
+static struct page *find_get_entry(struct address_space *mapping, pgoff_t index)
{
XA_STATE(xas, &mapping->i_pages, index);
struct page *page;
@@ -1711,39 +1711,6 @@ struct page *find_get_entry(struct address_space *mapping, pgoff_t index)
return page;
}
-/**
- * find_lock_entry - Locate and lock a page cache entry.
- * @mapping: The address_space to search.
- * @index: The page cache index.
- *
- * Looks up the page at @mapping & @index. If there is a page in the
- * cache, the head page is returned locked and with an increased refcount.
- *
- * If the slot holds a shadow entry of a previously evicted page, or a
- * swap entry from shmem/tmpfs, it is returned.
- *
- * Context: May sleep.
- * Return: The head page or shadow entry, %NULL if nothing is found.
- */
-struct page *find_lock_entry(struct address_space *mapping, pgoff_t index)
-{
- struct page *page;
-
-repeat:
- page = find_get_entry(mapping, index);
- if (page && !xa_is_value(page)) {
- lock_page(page);
- /* Has the page been truncated? */
- if (unlikely(page->mapping != mapping)) {
- unlock_page(page);
- put_page(page);
- goto repeat;
- }
- VM_BUG_ON_PAGE(!thp_contains(page, index), page);
- }
- return page;
-}
-
/**
* pagecache_get_page - Find and get a reference to a page.
* @mapping: The address_space to search.
@@ -1759,6 +1726,8 @@ struct page *find_lock_entry(struct address_space *mapping, pgoff_t index)
* * %FGP_LOCK - The page is returned locked.
* * %FGP_HEAD - If the page is present and a THP, return the head page
* rather than the exact page specified by the index.
+ * * %FGP_ENTRY - If there is a shadow / swap / DAX entry, return it
+ * instead of allocating a new page to replace it.
* * %FGP_CREAT - If no page is present then a new page is allocated using
* @gfp_mask and added to the page cache and the VM's LRU list.
* The page is returned locked and with an increased refcount.
@@ -1783,8 +1752,11 @@ struct page *pagecache_get_page(struct address_space *mapping, pgoff_t index,
repeat:
page = find_get_entry(mapping, index);
- if (xa_is_value(page))
+ if (xa_is_value(page)) {
+ if (fgp_flags & FGP_ENTRY)
+ return page;
page = NULL;
+ }
if (!page)
goto no_page;
diff --git a/mm/internal.h b/mm/internal.h
index c43ccdddb0f6..93880d460e12 100644
--- a/mm/internal.h
+++ b/mm/internal.h
@@ -60,9 +60,6 @@ static inline void force_page_cache_readahead(struct address_space *mapping,
force_page_cache_ra(&ractl, &file->f_ra, nr_to_read);
}
-struct page *find_get_entry(struct address_space *mapping, pgoff_t index);
-struct page *find_lock_entry(struct address_space *mapping, pgoff_t index);
-
/**
* page_evictable - test whether a page is evictable
* @page: the page to test
diff --git a/mm/shmem.c b/mm/shmem.c
index 8076c171731c..c4feb05425f2 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -1831,7 +1831,8 @@ static int shmem_getpage_gfp(struct inode *inode, pgoff_t index,
sbinfo = SHMEM_SB(inode->i_sb);
charge_mm = vma ? vma->vm_mm : current->mm;
- page = find_lock_entry(mapping, index);
+ page = pagecache_get_page(mapping, index,
+ FGP_ENTRY | FGP_HEAD | FGP_LOCK, 0);
if (xa_is_value(page)) {
error = shmem_swapin_page(inode, index, &page,
sgp, gfp, vma, fault_type);
diff --git a/mm/swap_state.c b/mm/swap_state.c
index d2161154d873..7cb4433edaa2 100644
--- a/mm/swap_state.c
+++ b/mm/swap_state.c
@@ -427,7 +427,8 @@ struct page *find_get_incore_page(struct address_space *mapping, pgoff_t index)
{
swp_entry_t swp;
struct swap_info_struct *si;
- struct page *page = find_get_entry(mapping, index);
+ struct page *page = pagecache_get_page(mapping, index,
+ FGP_ENTRY | FGP_HEAD, 0);
if (!page)
return page;
--
2.28.0
next prev parent reply other threads:[~2020-11-12 21:27 UTC|newest]
Thread overview: 58+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-11-12 21:26 [PATCH v4 00/16] Overhaul multi-page lookups for THP Matthew Wilcox (Oracle)
2020-11-12 21:26 ` [PATCH v4 01/16] mm: Make pagecache tagged lookups return only head pages Matthew Wilcox (Oracle)
2020-11-14 9:53 ` Christoph Hellwig
2020-11-12 21:26 ` [PATCH v4 02/16] mm/shmem: Use pagevec_lookup in shmem_unlock_mapping Matthew Wilcox (Oracle)
2020-11-14 9:53 ` Christoph Hellwig
2020-11-12 21:26 ` [PATCH v4 03/16] mm/swap: Optimise get_shadow_from_swap_cache Matthew Wilcox (Oracle)
2020-11-14 9:53 ` Christoph Hellwig
2020-11-12 21:26 ` Matthew Wilcox (Oracle) [this message]
2020-11-14 10:00 ` [PATCH v4 04/16] mm: Add FGP_ENTRY Christoph Hellwig
2020-11-12 21:26 ` [PATCH v4 05/16] mm/filemap: Rename find_get_entry to mapping_get_entry Matthew Wilcox (Oracle)
2020-11-14 10:01 ` Christoph Hellwig
2020-11-12 21:26 ` [PATCH v4 06/16] mm/filemap: Add helper for finding pages Matthew Wilcox (Oracle)
2020-11-14 10:03 ` Christoph Hellwig
2020-11-14 15:15 ` Matthew Wilcox
2020-11-12 21:26 ` [PATCH v4 07/16] mm/filemap: Add mapping_seek_hole_data Matthew Wilcox (Oracle)
2020-11-14 10:04 ` Christoph Hellwig
2020-11-12 21:26 ` [PATCH v4 08/16] iomap: Use mapping_seek_hole_data Matthew Wilcox (Oracle)
2020-11-14 10:06 ` Christoph Hellwig
2020-11-12 21:26 ` [PATCH v4 09/16] mm: Add and use find_lock_entries Matthew Wilcox (Oracle)
2020-11-14 10:07 ` Christoph Hellwig
2020-11-12 21:26 ` [PATCH v4 10/16] mm: Add an 'end' parameter to find_get_entries Matthew Wilcox (Oracle)
2020-11-14 10:08 ` Christoph Hellwig
2020-11-12 21:26 ` [PATCH v4 11/16] mm: Add an 'end' parameter to pagevec_lookup_entries Matthew Wilcox (Oracle)
2020-11-14 10:19 ` Christoph Hellwig
2020-11-12 21:26 ` [PATCH v4 12/16] mm: Remove nr_entries parameter from pagevec_lookup_entries Matthew Wilcox (Oracle)
2020-11-14 10:19 ` Christoph Hellwig
2020-11-12 21:26 ` [PATCH v4 13/16] mm: Pass pvec directly to find_get_entries Matthew Wilcox (Oracle)
2020-11-14 10:21 ` Christoph Hellwig
2020-11-14 15:22 ` Matthew Wilcox
2020-11-12 21:26 ` [PATCH v4 14/16] mm: Remove pagevec_lookup_entries Matthew Wilcox (Oracle)
2020-11-14 10:22 ` Christoph Hellwig
2020-11-12 21:26 ` [PATCH v4 15/16] mm/truncate,shmem: Handle truncates that split THPs Matthew Wilcox (Oracle)
2020-11-12 21:26 ` [PATCH v4 16/16] mm/filemap: Return only head pages from find_get_entries Matthew Wilcox (Oracle)
2020-11-14 10:23 ` Christoph Hellwig
2020-11-16 10:34 ` [PATCH v4 00/16] Overhaul multi-page lookups for THP Hugh Dickins
2020-11-16 15:14 ` Matthew Wilcox
2020-11-16 21:27 ` Hugh Dickins
2020-11-17 15:39 ` Matthew Wilcox
2020-11-17 16:26 ` Hugh Dickins
2020-11-17 19:15 ` Matthew Wilcox
2020-11-17 23:43 ` Matthew Wilcox
2020-11-25 2:32 ` Matthew Wilcox
2020-11-25 2:50 ` Hugh Dickins
2020-11-25 2:56 ` Hugh Dickins
2020-11-25 23:08 ` Andrew Morton
2020-11-26 0:11 ` Hugh Dickins
2020-11-26 12:15 ` Matthew Wilcox
2020-11-26 19:24 ` Hugh Dickins
2020-11-26 20:07 ` Matthew Wilcox
2020-11-30 19:45 ` Hugh Dickins
2020-12-01 4:52 ` Hugh Dickins
[not found] ` <CGME20201203154604eucas1p200d001d25dd344a1dd1c7da34f35aad0@eucas1p2.samsung.com>
2020-12-03 15:46 ` Marek Szyprowski
[not found] ` <CGME20201203172725eucas1p2fddec1d269c55095859d490942b78b93@eucas1p2.samsung.com>
2020-12-03 17:27 ` Marek Szyprowski
2020-12-03 21:27 ` Qian Cai
2020-12-03 22:19 ` Hugh Dickins
2020-12-03 21:45 ` Hugh Dickins
2021-02-23 22:58 ` Andrew Morton
2021-02-23 23:27 ` 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=20201112212641.27837-5-willy@infradead.org \
--to=willy@infradead.org \
--cc=akpm@linux-foundation.org \
--cc=dchinner@redhat.com \
--cc=hannes@cmpxchg.org \
--cc=hch@lst.de \
--cc=hughd@google.com \
--cc=linux-fsdevel@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=yang.shi@linux.alibaba.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).