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>
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