diff options
author | Denys Vlasenko <dvlasenk@redhat.com> | 2016-03-17 14:22:47 -0700 |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2016-03-17 15:09:34 -0700 |
commit | e3bde9568d992c5f985e6e30731a5f9f9bef7b13 (patch) | |
tree | 861438397ca7cbedeab03b3c2ba995b1d437a728 /include | |
parent | bc27fb68aaad44dd8f5c34924f05721f0abaeec1 (diff) |
include/linux/unaligned: force inlining of byteswap operations
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,
the following functions get deinlined many times.
Examples of disassembly:
<get_unaligned_be16> (24 copies, 108 calls):
66 8b 07 mov (%rdi),%ax
55 push %rbp
48 89 e5 mov %rsp,%rbp
86 e0 xchg %ah,%al
5d pop %rbp
c3 retq
<get_unaligned_be32> (25 copies, 181 calls):
8b 07 mov (%rdi),%eax
55 push %rbp
48 89 e5 mov %rsp,%rbp
0f c8 bswap %eax
5d pop %rbp
c3 retq
<get_unaligned_be64> (23 copies, 94 calls):
48 8b 07 mov (%rdi),%rax
55 push %rbp
48 89 e5 mov %rsp,%rbp
48 0f c8 bswap %rax
5d pop %rbp
c3 retq
<put_unaligned_be16> (2 copies, 11 calls):
89 f8 mov %edi,%eax
55 push %rbp
c1 ef 08 shr $0x8,%edi
c1 e0 08 shl $0x8,%eax
09 c7 or %eax,%edi
48 89 e5 mov %rsp,%rbp
66 89 3e mov %di,(%rsi)
<put_unaligned_be32> (8 copies, 43 calls):
55 push %rbp
0f cf bswap %edi
89 3e mov %edi,(%rsi)
48 89 e5 mov %rsp,%rbp
5d pop %rbp
c3 retq
<put_unaligned_be64> (26 copies, 157 calls):
55 push %rbp
48 0f cf bswap %rdi
48 89 3e mov %rdi,(%rsi)
48 89 e5 mov %rsp,%rbp
5d pop %rbp
c3 retq
This patch fixes this via s/inline/__always_inline/.
It only affects arches with efficient unaligned access insns, such as x86.
(arched which lack such ops do not include linux/unaligned/access_ok.h)
Code size decrease after the patch is ~8.5k:
text data bss dec hex filename
92197848 20826112 36417536 149441496 8e84bd8 vmlinux
92189231 20826144 36417536 149432911 8e82a4f vmlinux6_unaligned_be_after
Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>
Acked-by: Ingo Molnar <mingo@kernel.org>
Cc: Thomas Graf <tgraf@suug.ch>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include')
-rw-r--r-- | include/linux/unaligned/access_ok.h | 24 |
1 files changed, 12 insertions, 12 deletions
diff --git a/include/linux/unaligned/access_ok.h b/include/linux/unaligned/access_ok.h index 99c1b4d20b0f..33383ca23837 100644 --- a/include/linux/unaligned/access_ok.h +++ b/include/linux/unaligned/access_ok.h @@ -4,62 +4,62 @@ #include <linux/kernel.h> #include <asm/byteorder.h> -static inline u16 get_unaligned_le16(const void *p) +static __always_inline u16 get_unaligned_le16(const void *p) { return le16_to_cpup((__le16 *)p); } -static inline u32 get_unaligned_le32(const void *p) +static __always_inline u32 get_unaligned_le32(const void *p) { return le32_to_cpup((__le32 *)p); } -static inline u64 get_unaligned_le64(const void *p) +static __always_inline u64 get_unaligned_le64(const void *p) { return le64_to_cpup((__le64 *)p); } -static inline u16 get_unaligned_be16(const void *p) +static __always_inline u16 get_unaligned_be16(const void *p) { return be16_to_cpup((__be16 *)p); } -static inline u32 get_unaligned_be32(const void *p) +static __always_inline u32 get_unaligned_be32(const void *p) { return be32_to_cpup((__be32 *)p); } -static inline u64 get_unaligned_be64(const void *p) +static __always_inline u64 get_unaligned_be64(const void *p) { return be64_to_cpup((__be64 *)p); } -static inline void put_unaligned_le16(u16 val, void *p) +static __always_inline void put_unaligned_le16(u16 val, void *p) { *((__le16 *)p) = cpu_to_le16(val); } -static inline void put_unaligned_le32(u32 val, void *p) +static __always_inline void put_unaligned_le32(u32 val, void *p) { *((__le32 *)p) = cpu_to_le32(val); } -static inline void put_unaligned_le64(u64 val, void *p) +static __always_inline void put_unaligned_le64(u64 val, void *p) { *((__le64 *)p) = cpu_to_le64(val); } -static inline void put_unaligned_be16(u16 val, void *p) +static __always_inline void put_unaligned_be16(u16 val, void *p) { *((__be16 *)p) = cpu_to_be16(val); } -static inline void put_unaligned_be32(u32 val, void *p) +static __always_inline void put_unaligned_be32(u32 val, void *p) { *((__be32 *)p) = cpu_to_be32(val); } -static inline void put_unaligned_be64(u64 val, void *p) +static __always_inline void put_unaligned_be64(u64 val, void *p) { *((__be64 *)p) = cpu_to_be64(val); } |