lkml.org 
[lkml]   [2014]   [Apr]   [3]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
Subject[RFC PATCH 0/2] Emulator speedups - avoid initializations where possible
Date
While initializing emulation context structure, kvm memsets to 0 a 
number of fields some of which are redundant since they get set eventually.
This patch attempts at avoiding some of them.

Here are some before/after numbers on a Haswell host
Note : The before numbers already include Paolo's RFC posted here :
http://comments.gmane.org/gmane.linux.kernel/1676101

Before:
667 cycles/emulated jump instruction
839 cycles/emulated move instruction
892 cycles/emulated arithmetic instruction
995 cycles/emulated memory load instruction
1026 cycles/emulated memory store instruction
1022 cycles/emulated memory RMW instruction

After:
639 cycles/emulated jump instruction
786 cycles/emulated move instruction
802 cycles/emulated arithmetic instruction
936 cycles/emulated memory load instruction
970 cycles/emulated memory store instruction
1000 cycles/emulated memory RMW instruction

Bandan Das (2):
KVM: emulate: move init_decode_cache to emulate.c
KVM: emulate: clean up initializations in init_decode_cache

arch/x86/include/asm/kvm_emulate.h | 17 +++++++------
arch/x86/kvm/emulate.c | 49 ++++++++++++++++++++++++++++++++++++++
arch/x86/kvm/x86.c | 13 ----------
3 files changed, 59 insertions(+), 20 deletions(-)

--
1.8.3.1



\
 
 \ /
  Last update: 2014-04-04 00:41    [W:0.232 / U:0.208 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site