WSL2-Linux-Kernel/arch/x86/entry
Andy Lutomirski e786041153 x86/entry/compat: In SYSENTER, sink AC clearing below the existing FLAGS test
CLAC is slow, and the SYSENTER code already has an unlikely path
that runs if unusual flags are set.  Drop the CLAC and instead rely
on the unlikely path to clear AC.

This seems to save ~24 cycles on my Skylake laptop.  (Hey, Intel,
make this faster please!)

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Cc: Andrew Cooper <andrew.cooper3@citrix.com>
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: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/90d6db2189f9add83bc7bddd75a0c19ebbd676b2.1457578375.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-03-10 09:48:12 +01:00
..
syscalls x86/syscalls/64: Mark sys_iopl() as using ptregs 2016-02-01 08:53:25 +01:00
vdso x86/vdso: Use static_cpu_has() 2016-01-30 11:22:23 +01:00
vsyscall x86/vdso: Disallow vvar access to vclock IO for never-used vclocks 2016-01-12 11:59:35 +01:00
Makefile x86/entry: Move C entry and exit code to arch/x86/entry/common.c 2015-07-07 10:59:05 +02:00
calling.h x86/asm/entry: Remove unused SAVE_ALL/RESTORE_ALL macros for !CONFIG_x86_64 2016-01-19 08:24:03 +01:00
common.c x86/entry/compat: Keep TS_COMPAT set during signal delivery 2016-02-17 09:51:06 +01:00
entry_32.S x86/entry/32: Introduce and use X86_BUG_ESPFIX instead of paravirt_enabled 2016-03-08 14:16:44 +01:00
entry_64.S x86/entry/64: Fix fast-path syscall return register state 2016-02-01 08:53:25 +01:00
entry_64_compat.S x86/entry/compat: In SYSENTER, sink AC clearing below the existing FLAGS test 2016-03-10 09:48:12 +01:00
syscall_32.c x86/syscalls: Add syscall entry qualifiers 2016-01-29 09:46:38 +01:00
syscall_64.c x86/entry/64: Always run ptregs-using syscalls on the slow path 2016-01-29 09:46:38 +01:00
thunk_32.S Merge branch 'x86-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2015-06-22 17:59:09 -07:00
thunk_64.S Merge branch 'x86-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2015-06-22 17:59:09 -07:00