From: Paolo Bonzini <pbonzini@redhat.com>
To: qemu-devel@nongnu.org
Subject: [Qemu-devel] [PATCH 0/3] target-arm: cache tbflags in CPUARMState
Date: Wed, 14 Sep 2016 11:56:50 +0200 [thread overview]
Message-ID: <1473847013-20191-1-git-send-email-pbonzini@redhat.com> (raw)
Computing TranslationBlock flags is pretty expensive on ARM, especially
32-bit. Because tbflags are computed on every tb lookup, it is not
unlikely to see cpu_get_tb_cpu_state close to the top of the profile
now that QHT makes the hash table much more efficient.
However, most tbflags only change when the EL is switched or after
MSR instructions. Based on this observation, this series caches these
tbflags in CPUARMState, resulting in a 10-15% speedup on 32-bit code.
Paolo
Paolo Bonzini (3):
target-arm: introduce cpu_dynamic_tb_cpu_flags
target-arm: add env->tbflags
target-arm: cache most tbflags
target-arm/cpu.c | 2 ++
target-arm/cpu.h | 58 ++++++++++++++++++++++++++++++++--------------
target-arm/helper.c | 2 ++
target-arm/helper.h | 1 +
target-arm/op_helper.c | 7 ++++++
target-arm/translate-a64.c | 4 ++++
target-arm/translate.c | 12 ++++++++--
target-arm/translate.h | 1 +
8 files changed, 68 insertions(+), 19 deletions(-)
--
2.7.4
next reply other threads:[~2016-09-14 9:58 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-09-14 9:56 Paolo Bonzini [this message]
2016-09-14 9:56 ` [Qemu-devel] [PATCH 1/3] target-arm: introduce cpu_dynamic_tb_cpu_flags Paolo Bonzini
2016-09-14 9:56 ` [Qemu-devel] [PATCH 2/3] target-arm: add env->tbflags Paolo Bonzini
2016-09-26 22:00 ` Peter Maydell
2016-09-27 8:15 ` Paolo Bonzini
2016-09-14 9:56 ` [Qemu-devel] [PATCH 3/3] target-arm: cache most tbflags Paolo Bonzini
2016-09-26 10:04 ` [Qemu-devel] [PATCH 0/3] target-arm: cache tbflags in CPUARMState Laurent Desnogues
2016-09-26 11:13 ` Laurent Desnogues
2016-11-10 11:42 ` Alex Bennée
2016-11-10 12:19 ` Paolo Bonzini
2016-11-10 13:37 ` Alex Bennée
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