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authorThomas Gleixner <[email protected]>2018-02-16 15:47:26 +0100
committerThomas Gleixner <[email protected]>2018-02-16 15:47:26 +0100
commit6dee6ae9d62642e81def4d461d71f13a6496ab59 (patch)
tree6c75d416c427a59f190e197ad83fe59b7bebf656 /include/linux/buffer_head.h
parent1beaeacdc88b537703d04d5536235d0bbb36db93 (diff)
parent0b24a0bbe2147815d982d9335c41bb10c04f40bc (diff)
Merge tag 'irqchip-4.16-2' of git://git.kernel.org/pub/scm/linux/kernel/git/maz/arm-platforms into irq/urgent
Pull irqchip updates for 4.16-rc2 from Marc Zyngier - A MIPS GIC fix for spurious, masked interrupts - A fix for a subtle IPI bug in GICv3 - Do not probe GICv3 ITSs that are marked as disabled - Multi-MSI support for GICv2m - Various cleanups
Diffstat (limited to 'include/linux/buffer_head.h')
-rw-r--r--include/linux/buffer_head.h6
1 files changed, 4 insertions, 2 deletions
diff --git a/include/linux/buffer_head.h b/include/linux/buffer_head.h
index 8b1bf8d3d4a2..894e5d125de6 100644
--- a/include/linux/buffer_head.h
+++ b/include/linux/buffer_head.h
@@ -81,11 +81,14 @@ struct buffer_head {
/*
* macro tricks to expand the set_buffer_foo(), clear_buffer_foo()
* and buffer_foo() functions.
+ * To avoid reset buffer flags that are already set, because that causes
+ * a costly cache line transition, check the flag first.
*/
#define BUFFER_FNS(bit, name) \
static __always_inline void set_buffer_##name(struct buffer_head *bh) \
{ \
- set_bit(BH_##bit, &(bh)->b_state); \
+ if (!test_bit(BH_##bit, &(bh)->b_state)) \
+ set_bit(BH_##bit, &(bh)->b_state); \
} \
static __always_inline void clear_buffer_##name(struct buffer_head *bh) \
{ \
@@ -151,7 +154,6 @@ void buffer_check_dirty_writeback(struct page *page,
void mark_buffer_dirty(struct buffer_head *bh);
void mark_buffer_write_io_error(struct buffer_head *bh);
-void init_buffer(struct buffer_head *, bh_end_io_t *, void *);
void touch_buffer(struct buffer_head *bh);
void set_bh_page(struct buffer_head *bh,
struct page *page, unsigned long offset);