git: kernel - Add syscall quick return path for x86-64
commit f20816468a05fb67cffa4458b6469614e36511bb
Author: Matthew Dillon <dillon@apollo.backplane.com>
Date: Sat Nov 12 15:04:56 2011 -0800
kernel - Add syscall quick return path for x86-64
* Flag the case where a sysretq can be performed to quickly return
from a system call instead of having to execute the slower doreti
code.
* This about halves syscall times for simple system calls such as
getuid(), and reduces longer syscalls by ~80ns or so on a fast
3.4GHz SandyBridge, but does not seem to really effect performance
a whole lot.
Taken-From: FreeBSD (loosely)
Summary of changes:
sys/cpu/i386/include/cpu.h | 2 ++
sys/cpu/x86_64/include/cpu.h | 2 ++
sys/emulation/linux/i386/linux_sysvec.c | 4 ++++
sys/platform/pc64/x86_64/exception.S | 24 ++++++++++++++++++++++++
sys/platform/pc64/x86_64/genassym.c | 1 +
sys/platform/pc64/x86_64/machdep.c | 4 ++++
sys/platform/pc64/x86_64/swtch.s | 6 ++++++
sys/platform/pc64/x86_64/tls.c | 1 +
sys/platform/pc64/x86_64/trap.c | 1 +
sys/sys/globaldata.h | 2 ++
10 files changed, 47 insertions(+), 0 deletions(-)
http://gitweb.dragonflybsd.org/dragonfly.git/commitdiff/f20816468a05fb67cffa4458b6469614e36511bb
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DragonFly BSD source repository