diff options
| author | Denys Vlasenko <dvlasenk@redhat.com> | 2015-08-04 16:15:15 +0200 | 
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2015-08-05 09:38:09 +0200 | 
| commit | d14edb1648221e59fc9fd47127fcc57bf26d759f (patch) | |
| tree | dbefdae5a56c1936b364580ac4b814a2a926b775 /lib/debugobjects.c | |
| parent | 1a1d48a4a8fde49aedc045d894efe67173d59fe0 (diff) | |
x86/hweight: Force inlining of __arch_hweight{32,64}()
With this config:
  http://busybox.net/~vda/kernel_config_OPTIMIZE_INLINING_and_Os
gcc-4.7.2 generates many copies of these tiny functions:
	__arch_hweight32 (35 copies):
	55                      push   %rbp
	e8 66 9b 4a 00          callq  __sw_hweight32
	48 89 e5                mov    %rsp,%rbp
	5d                      pop    %rbp
	c3                      retq
	__arch_hweight64 (8 copies):
	55                      push   %rbp
	e8 5e c2 8a 00          callq  __sw_hweight64
	48 89 e5                mov    %rsp,%rbp
	5d                      pop    %rbp
	c3                      retq
See https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66122
This patch fixes this via s/inline/__always_inline/
To avoid touching 32-bit case where such change was not tested
to be a win, reformat __arch_hweight64() to have completely
disjoint 64-bit and 32-bit implementations. IOW: made #ifdef /
32 bits and 64 bits instead of having #ifdef / #else / #endif
inside a single function body. Only 64-bit __arch_hweight64() is
__always_inline'd.
	    text     data      bss       dec  filename
	86971120 17195912 36659200 140826232  vmlinux.before
	86970954 17195912 36659200 140826066  vmlinux
Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Thomas Graf <tgraf@suug.ch>
Cc: linux-kernel@vger.kernel.org
Link: http://lkml.kernel.org/r/1438697716-28121-2-git-send-email-dvlasenk@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'lib/debugobjects.c')
0 files changed, 0 insertions, 0 deletions
