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| author |   Andy Lutomirski <luto@kernel.org> | 2015-10-05 17:48:24 -0700 |
|---|---|---|
| committer |   Ingo Molnar <mingo@kernel.org> | 2015-10-09 09:41:13 +0200 |
| commit | f5e6a9753ac2965564a14e6285a06f44043ed9c8 (patch) | |
| tree | 0582fb04b19ee92de88288a28f214d07db5abda7 /tools/testing/selftests/x86 | |
| parent | x86/entry: Split and inline prepare_exit_to_usermode() (diff) | |
| download | wireguard-linux-f5e6a9753ac2965564a14e6285a06f44043ed9c8.tar.xz wireguard-linux-f5e6a9753ac2965564a14e6285a06f44043ed9c8.zip | |
x86/entry: Split and inline syscall_return_slowpath()
GCC is unable to properly optimize functions that have a very
short likely case and a longer and register-heavier cold part --
it fails to sink all of the register saving and stack frame
setup code into the unlikely part.
Help it out with syscall_return_slowpath() by splitting it into
two parts and inline the hot part.
Saves 6 cycles for compat syscalls.
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Link: http://lkml.kernel.org/r/0f773a894ab15c589ac794c2d34ca6ba9b5335c9.1444091585.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'tools/testing/selftests/x86')
0 files changed, 0 insertions, 0 deletions