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authorDenys Vlasenko <dvlasenk@redhat.com>2016-03-17 14:18:21 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2016-03-17 15:09:34 -0700
commitee91ef6173e81819f5ff610c2485802081635657 (patch)
tree7260d83f05803a90d0d7ca57db6af6c6d884af08 /include/linux/buffer_head.h
parent075db1502ffd4ff8c58020167484a6e123ae01a3 (diff)
bufferhead: force inlining of buffer head flag operations
With both gcc 4.7.2 and 4.9.2, sometimes gcc mysteriously doesn't inline very small functions we expect to be inlined. See https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66122 With this .config: http://busybox.net/~vda/kernel_config_OPTIMIZE_INLINING_and_Os, set_buffer_foo(), clear_buffer_foo() and similar functions get deinlined about 60 times. Examples of disassembly: <set_buffer_mapped> (14 copies, 43 calls): 55 push %rbp 48 89 e5 mov %rsp,%rbp f0 80 0f 20 lock orb $0x20,(%rdi) 5d pop %rbp c3 retq <buffer_mapped> (3 copies, 34 calls): 48 8b 07 mov (%rdi),%rax 55 push %rbp 48 89 e5 mov %rsp,%rbp 48 c1 e8 05 shr $0x5,%rax 83 e0 01 and $0x1,%eax 5d pop %rbp c3 retq <set_buffer_new> (5 copies, 13 calls): 55 push %rbp 48 89 e5 mov %rsp,%rbp f0 80 0f 40 lock orb $0x40,(%rdi) 5d pop %rbp c3 retq This patch fixes this via s/inline/__always_inline/. This decreases vmlinux by about 3 kbytes. text data bss dec hex filename 88200439 19905208 36421632 144527279 89d4faf vmlinux2 88197239 19905240 36421632 144524111 89d434f vmlinux Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Thomas Graf <tgraf@suug.ch> Cc: Peter Zijlstra <peterz@infradead.org> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include/linux/buffer_head.h')
-rw-r--r--include/linux/buffer_head.h10
1 files changed, 5 insertions, 5 deletions
diff --git a/include/linux/buffer_head.h b/include/linux/buffer_head.h
index 89d9aa9e79bf..c67f052cc5e5 100644
--- a/include/linux/buffer_head.h
+++ b/include/linux/buffer_head.h
@@ -82,15 +82,15 @@ struct buffer_head {
* and buffer_foo() functions.
*/
#define BUFFER_FNS(bit, name) \
-static inline void set_buffer_##name(struct buffer_head *bh) \
+static __always_inline void set_buffer_##name(struct buffer_head *bh) \
{ \
set_bit(BH_##bit, &(bh)->b_state); \
} \
-static inline void clear_buffer_##name(struct buffer_head *bh) \
+static __always_inline void clear_buffer_##name(struct buffer_head *bh) \
{ \
clear_bit(BH_##bit, &(bh)->b_state); \
} \
-static inline int buffer_##name(const struct buffer_head *bh) \
+static __always_inline int buffer_##name(const struct buffer_head *bh) \
{ \
return test_bit(BH_##bit, &(bh)->b_state); \
}
@@ -99,11 +99,11 @@ static inline int buffer_##name(const struct buffer_head *bh) \
* test_set_buffer_foo() and test_clear_buffer_foo()
*/
#define TAS_BUFFER_FNS(bit, name) \
-static inline int test_set_buffer_##name(struct buffer_head *bh) \
+static __always_inline int test_set_buffer_##name(struct buffer_head *bh) \
{ \
return test_and_set_bit(BH_##bit, &(bh)->b_state); \
} \
-static inline int test_clear_buffer_##name(struct buffer_head *bh) \
+static __always_inline int test_clear_buffer_##name(struct buffer_head *bh) \
{ \
return test_and_clear_bit(BH_##bit, &(bh)->b_state); \
} \