[PATCH v13 019/137] mm/filemap: Add folio_lock_killable()
From: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Date: 2021-07-12 03:19:00
Also in:
linux-fsdevel, lkml
Subsystem:
memory management, page cache, the rest · Maintainers:
Andrew Morton, Matthew Wilcox, Linus Torvalds
This is like lock_page_killable() but for use by callers who know they have a folio. Convert __lock_page_killable() to be __folio_lock_killable(). This saves one call to compound_head() per contended call to lock_page_killable(). __folio_lock_killable() is 19 bytes smaller than __lock_page_killable() was. filemap_fault() shrinks by 74 bytes and __lock_page_or_retry() shrinks by 71 bytes. That's a total of 164 bytes of text saved. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Acked-by: Jeff Layton <jlayton@kernel.org> Acked-by: Kirill A. Shutemov <redacted> Acked-by: Vlastimil Babka <redacted> Reviewed-by: William Kucharski <redacted> --- include/linux/pagemap.h | 15 ++++++++++----- mm/filemap.c | 17 +++++++++-------- 2 files changed, 19 insertions(+), 13 deletions(-)
diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h
index 5c82933af2fe..3d78d96c163d 100644
--- a/include/linux/pagemap.h
+++ b/include/linux/pagemap.h@@ -654,7 +654,7 @@ static inline bool wake_page_match(struct wait_page_queue *wait_page, } void __folio_lock(struct folio *folio); -extern int __lock_page_killable(struct page *page); +int __folio_lock_killable(struct folio *folio); 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, unsigned int flags);
@@ -694,6 +694,14 @@ static inline void lock_page(struct page *page) __folio_lock(folio); } +static inline int folio_lock_killable(struct folio *folio) +{ + might_sleep(); + if (!folio_trylock(folio)) + return __folio_lock_killable(folio); + return 0; +} + /* * lock_page_killable is like lock_page but can be interrupted by fatal * signals. It returns 0 if it locked the page and -EINTR if it was
@@ -701,10 +709,7 @@ static inline void lock_page(struct page *page) */ static inline int lock_page_killable(struct page *page) { - might_sleep(); - if (!trylock_page(page)) - return __lock_page_killable(page); - return 0; + return folio_lock_killable(page_folio(page)); } /*
diff --git a/mm/filemap.c b/mm/filemap.c
index cc2682b72584..108cc825638f 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c@@ -1589,14 +1589,13 @@ void __folio_lock(struct folio *folio) } EXPORT_SYMBOL(__folio_lock); -int __lock_page_killable(struct page *__page) +int __folio_lock_killable(struct folio *folio) { - struct page *page = compound_head(__page); - wait_queue_head_t *q = page_waitqueue(page); - return wait_on_page_bit_common(q, page, PG_locked, TASK_KILLABLE, + wait_queue_head_t *q = page_waitqueue(&folio->page); + return wait_on_page_bit_common(q, &folio->page, PG_locked, TASK_KILLABLE, EXCLUSIVE); } -EXPORT_SYMBOL_GPL(__lock_page_killable); +EXPORT_SYMBOL_GPL(__folio_lock_killable); int __lock_page_async(struct page *page, struct wait_page_queue *wait) {
@@ -1638,6 +1637,8 @@ int __lock_page_async(struct page *page, struct wait_page_queue *wait) int __lock_page_or_retry(struct page *page, struct mm_struct *mm, unsigned int flags) { + struct folio *folio = page_folio(page); + if (fault_flag_allow_retry_first(flags)) { /* * CAUTION! In this case, mmap_lock is not released
@@ -1656,13 +1657,13 @@ int __lock_page_or_retry(struct page *page, struct mm_struct *mm, if (flags & FAULT_FLAG_KILLABLE) { int ret; - ret = __lock_page_killable(page); + ret = __folio_lock_killable(folio); if (ret) { mmap_read_unlock(mm); return 0; } } else { - __folio_lock(page_folio(page)); + __folio_lock(folio); } return 1;
@@ -2851,7 +2852,7 @@ 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(&folio->page)) { + if (__folio_lock_killable(folio)) { /* * We didn't have the right flags to drop the mmap_lock, * but all fault_handlers only check for fatal signals
--
2.30.2