[PATCH 1/2] mm: Remove definition of clear_bit_unlock_is_negative_byte
From: Matthew Wilcox <willy@infradead.org>
Date: 2020-03-26 12:24:32
Also in:
linux-fsdevel
Subsystem:
memory management, page cache, the rest · Maintainers:
Andrew Morton, Matthew Wilcox, Linus Torvalds
From: "Matthew Wilcox (Oracle)" <willy@infradead.org>
This local definition hasn't been used since commit 84c6591103db
("locking/atomics, asm-generic/bitops/lock.h: Rewrite using
atomic_fetch_*()") which provided a default definition.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Will Deacon <redacted>
---
mm/filemap.c | 23 -----------------------
1 file changed, 23 deletions(-)
diff --git a/mm/filemap.c b/mm/filemap.c
index 80f7e1ae744c..312afbfcb49a 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c@@ -1248,29 +1248,6 @@ void add_page_wait_queue(struct page *page, wait_queue_entry_t *waiter) } EXPORT_SYMBOL_GPL(add_page_wait_queue); -#ifndef clear_bit_unlock_is_negative_byte - -/* - * PG_waiters is the high bit in the same byte as PG_lock. - * - * On x86 (and on many other architectures), we can clear PG_lock and - * test the sign bit at the same time. But if the architecture does - * not support that special operation, we just do this all by hand - * instead. - * - * The read of PG_waiters has to be after (or concurrently with) PG_locked - * being cleared, but a memory barrier should be unneccssary since it is - * in the same byte as PG_locked. - */ -static inline bool clear_bit_unlock_is_negative_byte(long nr, volatile void *mem) -{ - clear_bit_unlock(nr, mem); - /* smp_mb__after_atomic(); */ - return test_bit(PG_waiters, mem); -} - -#endif - /** * unlock_page - unlock a locked page * @page: the page
--
2.25.1