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>,
Christoph Hellwig <hch@lst.de>, Jeff Layton <jlayton@kernel.org>
Subject: [PATCH v8 18/31] mm/filemap: Add folio_lock
Date: Fri, 30 Apr 2021 19:07:27 +0100 [thread overview]
Message-ID: <20210430180740.2707166-19-willy@infradead.org> (raw)
In-Reply-To: <20210430180740.2707166-1-willy@infradead.org>
This is like lock_page() but for use by callers who know they have a folio.
Convert __lock_page() to be __folio_lock(). This saves one call to
compound_head() per contended call to lock_page().
Saves 362 bytes of text; mostly from improved register allocation and
inlining decisions. __folio_lock is 59 bytes while __lock_page was 79.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: Jeff Layton <jlayton@kernel.org>
---
include/linux/pagemap.h | 24 +++++++++++++++++++-----
mm/filemap.c | 29 +++++++++++++++--------------
2 files changed, 34 insertions(+), 19 deletions(-)
diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h
index 9126c0db3a60..ff81be103539 100644
--- a/include/linux/pagemap.h
+++ b/include/linux/pagemap.h
@@ -714,7 +714,7 @@ static inline bool wake_page_match(struct wait_page_queue *wait_page,
return true;
}
-extern void __lock_page(struct page *page);
+void __folio_lock(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,
@@ -722,13 +722,24 @@ extern int __lock_page_or_retry(struct page *page, struct mm_struct *mm,
void unlock_page(struct page *page);
void folio_unlock(struct folio *folio);
+static inline bool folio_trylock(struct folio *folio)
+{
+ return likely(!test_and_set_bit_lock(PG_locked, folio_flags(folio, 0)));
+}
+
/*
* 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 folio_trylock(page_folio(page));
+}
+
+static inline void folio_lock(struct folio *folio)
+{
+ might_sleep();
+ if (!folio_trylock(folio))
+ __folio_lock(folio);
}
/*
@@ -736,9 +747,12 @@ static inline int trylock_page(struct page *page)
*/
static inline void lock_page(struct page *page)
{
+ struct folio *folio;
might_sleep();
- if (!trylock_page(page))
- __lock_page(page);
+
+ folio = page_folio(page);
+ if (!folio_trylock(folio))
+ __folio_lock(folio);
}
/*
diff --git a/mm/filemap.c b/mm/filemap.c
index 090b303bcd45..6935b068856f 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -1187,7 +1187,7 @@ 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.
+ * __folio_lock() 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.
@@ -1576,17 +1576,16 @@ 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
+ * __folio_lock - 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 __folio_lock(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(__folio_lock);
int __lock_page_killable(struct page *__page)
{
@@ -1661,10 +1660,10 @@ int __lock_page_or_retry(struct page *page, struct mm_struct *mm,
return 0;
}
} else {
- __lock_page(page);
+ __folio_lock(page_folio(page));
}
- return 1;
+ return 1;
}
/**
@@ -2815,7 +2814,9 @@ 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 (folio_trylock(folio))
return 1;
/*
@@ -2828,7 +2829,7 @@ 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
@@ -2840,11 +2841,11 @@ static int lock_page_maybe_drop_mmap(struct vm_fault *vmf, struct page *page,
return 0;
}
} else
- __lock_page(page);
+ __folio_lock(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
--
2.30.2
next prev parent reply other threads:[~2021-04-30 18:25 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 ` [PATCH v8 07/31] mm: Add folio_get Matthew Wilcox (Oracle)
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 ` Matthew Wilcox (Oracle) [this message]
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
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