From: "Matthew Wilcox (Oracle)" <willy@infradead.org>
To: linux-fsdevel@vger.kernel.org, linux-mm@kvack.org
Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>,
linux-kernel@vger.kernel.org
Subject: [PATCH v2 14/27] mm: Add lock_folio
Date: Mon, 18 Jan 2021 17:01:35 +0000 [thread overview]
Message-ID: <20210118170148.3126186-15-willy@infradead.org> (raw)
In-Reply-To: <20210118170148.3126186-1-willy@infradead.org>
This is like lock_page() but for use by callers who know they have a folio.
Convert __lock_page() to be __lock_folio(). This saves one call to
compound_head() per contended call to lock_page().
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
---
include/linux/pagemap.h | 21 +++++++++++++++------
mm/filemap.c | 29 +++++++++++++++--------------
2 files changed, 30 insertions(+), 20 deletions(-)
diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h
index 44675104008b..03b67915b0f7 100644
--- a/include/linux/pagemap.h
+++ b/include/linux/pagemap.h
@@ -618,7 +618,7 @@ static inline bool wake_page_match(struct wait_page_queue *wait_page,
return true;
}
-extern void __lock_page(struct page *page);
+void __lock_folio(struct folio *folio);
extern int __lock_page_killable(struct page *page);
extern int __lock_page_async(struct page *page, struct wait_page_queue *wait);
extern int __lock_page_or_retry(struct page *page, struct mm_struct *mm,
@@ -639,13 +639,24 @@ static inline void unlock_page(struct page *page)
return unlock_folio(page_folio(page));
}
+static inline bool trylock_folio(struct folio *folio)
+{
+ return likely(!test_and_set_bit_lock(PG_locked, folio_flags(folio)));
+}
+
/*
* Return true if the page was successfully locked
*/
static inline int trylock_page(struct page *page)
{
- page = compound_head(page);
- return (likely(!test_and_set_bit_lock(PG_locked, &page->flags)));
+ return trylock_folio(page_folio(page));
+}
+
+static inline void lock_folio(struct folio *folio)
+{
+ might_sleep();
+ if (!trylock_folio(folio))
+ __lock_folio(folio);
}
/*
@@ -653,9 +664,7 @@ static inline int trylock_page(struct page *page)
*/
static inline void lock_page(struct page *page)
{
- might_sleep();
- if (!trylock_page(page))
- __lock_page(page);
+ lock_folio(page_folio(page));
}
/*
diff --git a/mm/filemap.c b/mm/filemap.c
index 31470b36ac89..167552fad5a6 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -1155,7 +1155,7 @@ static void wake_up_page(struct page *page, int bit)
*/
enum behavior {
EXCLUSIVE, /* Hold ref to page and take the bit when woken, like
- * __lock_page() waiting on then setting PG_locked.
+ * __lock_folio() waiting on then setting PG_locked.
*/
SHARED, /* Hold ref to page and check the bit when woken, like
* wait_on_page_writeback() waiting on PG_writeback.
@@ -1518,17 +1518,16 @@ void page_endio(struct page *page, bool is_write, int err)
EXPORT_SYMBOL_GPL(page_endio);
/**
- * __lock_page - get a lock on the page, assuming we need to sleep to get it
- * @__page: the page to lock
+ * __lock_folio - Get a lock on the folio, assuming we need to sleep to get it.
+ * @folio: The folio to lock
*/
-void __lock_page(struct page *__page)
+void __lock_folio(struct folio *folio)
{
- struct page *page = compound_head(__page);
- wait_queue_head_t *q = page_waitqueue(page);
- wait_on_page_bit_common(q, page, PG_locked, TASK_UNINTERRUPTIBLE,
+ wait_queue_head_t *q = page_waitqueue(&folio->page);
+ wait_on_page_bit_common(q, &folio->page, PG_locked, TASK_UNINTERRUPTIBLE,
EXCLUSIVE);
}
-EXPORT_SYMBOL(__lock_page);
+EXPORT_SYMBOL(__lock_folio);
int __lock_page_killable(struct page *__page)
{
@@ -1582,10 +1581,10 @@ int __lock_page_or_retry(struct page *page, struct mm_struct *mm,
return 0;
}
} else {
- __lock_page(page);
+ __lock_folio(page_folio(page));
}
- return 1;
+ return 1;
}
/**
@@ -2763,7 +2762,9 @@ loff_t mapping_seek_hole_data(struct address_space *mapping, loff_t start,
static int lock_page_maybe_drop_mmap(struct vm_fault *vmf, struct page *page,
struct file **fpin)
{
- if (trylock_page(page))
+ struct folio *folio = page_folio(page);
+
+ if (trylock_folio(folio))
return 1;
/*
@@ -2776,7 +2777,7 @@ static int lock_page_maybe_drop_mmap(struct vm_fault *vmf, struct page *page,
*fpin = maybe_unlock_mmap_for_io(vmf, *fpin);
if (vmf->flags & FAULT_FLAG_KILLABLE) {
- if (__lock_page_killable(page)) {
+ if (__lock_page_killable(&folio->page)) {
/*
* We didn't have the right flags to drop the mmap_lock,
* but all fault_handlers only check for fatal signals
@@ -2788,11 +2789,11 @@ static int lock_page_maybe_drop_mmap(struct vm_fault *vmf, struct page *page,
return 0;
}
} else
- __lock_page(page);
+ __lock_folio(folio);
+
return 1;
}
-
/*
* Synchronous readahead happens when we don't even find a page in the page
* cache at all. We don't want to perform IO under the mmap sem, so if we have
--
2.29.2
next prev parent reply other threads:[~2021-01-18 17:13 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-18 17:01 [PATCH v2 00/27] Page folios Matthew Wilcox (Oracle)
2021-01-18 17:01 ` [PATCH v2 01/27] mm: Introduce struct folio Matthew Wilcox (Oracle)
2021-01-18 17:01 ` [PATCH v2 02/27] mm: Add folio_pgdat Matthew Wilcox (Oracle)
2021-01-18 17:01 ` [PATCH v2 03/27] mm/vmstat: Add folio stat wrappers Matthew Wilcox (Oracle)
2021-01-18 17:01 ` [PATCH v2 04/27] mm/debug: Add VM_BUG_ON_FOLIO and VM_WARN_ON_ONCE_FOLIO Matthew Wilcox (Oracle)
2021-01-18 17:01 ` [PATCH v2 05/27] mm: Add put_folio Matthew Wilcox (Oracle)
2021-01-18 17:01 ` [PATCH v2 06/27] mm: Add get_folio Matthew Wilcox (Oracle)
2021-01-18 17:01 ` [PATCH v2 07/27] mm: Create FolioFlags Matthew Wilcox (Oracle)
2021-01-18 17:01 ` [PATCH v2 08/27] mm: Handle per-folio private data Matthew Wilcox (Oracle)
2021-01-18 17:01 ` [PATCH v2 09/27] mm: Add folio_index, folio_page and folio_contains Matthew Wilcox (Oracle)
2021-01-18 17:01 ` [PATCH v2 10/27] mm/util: Add folio_mapping and folio_file_mapping Matthew Wilcox (Oracle)
2021-01-18 17:01 ` [PATCH v2 11/27] mm/memcg: Add folio_memcg, lock_folio_memcg and unlock_folio_memcg Matthew Wilcox (Oracle)
2021-01-18 17:01 ` [PATCH v2 12/27] mm/memcg: Add mem_cgroup_folio_lruvec Matthew Wilcox (Oracle)
2021-01-18 17:01 ` [PATCH v2 13/27] mm: Add unlock_folio Matthew Wilcox (Oracle)
2021-01-18 17:01 ` Matthew Wilcox (Oracle) [this message]
2021-01-18 17:01 ` [PATCH v2 15/27] mm: Add lock_folio_killable Matthew Wilcox (Oracle)
2021-01-18 17:01 ` [PATCH v2 16/27] mm: Convert lock_page_async to lock_folio_async Matthew Wilcox (Oracle)
2021-01-18 17:01 ` [PATCH v2 17/27] mm/filemap: Convert lock_page_for_iocb to lock_folio_for_iocb Matthew Wilcox (Oracle)
2021-01-18 17:01 ` [PATCH v2 18/27] mm/filemap: Convert wait_on_page_locked_async to wait_on_folio_locked_async Matthew Wilcox (Oracle)
2021-01-18 17:01 ` [PATCH v2 19/27] mm/filemap: Convert end_page_writeback to end_folio_writeback Matthew Wilcox (Oracle)
2021-01-18 17:01 ` [PATCH v2 20/27] mm: Convert wait_on_page_bit to wait_on_folio_bit Matthew Wilcox (Oracle)
2021-01-18 17:01 ` [PATCH v2 21/27] mm: Add wait_for_stable_folio and wait_on_folio_writeback Matthew Wilcox (Oracle)
2021-01-18 17:01 ` [PATCH v2 22/27] mm: Add wait_on_folio_locked & wait_on_folio_locked_killable Matthew Wilcox (Oracle)
2021-01-18 17:01 ` [PATCH v2 23/27] mm: Convert lock_page_or_retry to lock_folio_or_retry Matthew Wilcox (Oracle)
2021-01-18 17:01 ` [PATCH v2 24/27] mm/filemap: Convert wake_up_page_bit to wake_up_folio_bit Matthew Wilcox (Oracle)
2021-01-18 17:01 ` [PATCH v2 25/27] mm: Convert test_clear_page_writeback to test_clear_folio_writeback Matthew Wilcox (Oracle)
2021-01-18 17:01 ` [PATCH v2 26/27] mm/filemap: Convert page wait queues to be folios Matthew Wilcox (Oracle)
2021-01-18 17:01 ` [PATCH v2 27/27] cachefiles: Switch to wait_page_key Matthew Wilcox (Oracle)
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=20210118170148.3126186-15-willy@infradead.org \
--to=willy@infradead.org \
--cc=linux-fsdevel@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.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).