From: Paolo Bonzini <pbonzini@redhat.com>
To: "Alex Bennée" <alex.bennee@linaro.org>
Cc: qemu-devel@nongnu.org
Subject: Re: [Qemu-devel] [PATCH 0/3] target-arm: cache tbflags in CPUARMState
Date: Thu, 10 Nov 2016 13:19:26 +0100 [thread overview]
Message-ID: <b161663b-756f-677d-db31-e57af037aaa2@redhat.com> (raw)
In-Reply-To: <87k2cb8st5.fsf@linaro.org>
On 10/11/2016 12:42, Alex Bennée wrote:
>
> Paolo Bonzini <pbonzini@redhat.com> writes:
>
>> 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.
>
> Hi,
>
> I'm starting to clear out my review queue but I notice these now longer
> apply cleanly to master. Where you going to re-issue the series once
> you'd addressed Peter's concerns?
Yes, I didn't want to send them two days before soft freeze and Peter's
vacation. :)
Paolo
next prev parent reply other threads:[~2016-11-10 12:19 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-09-14 9:56 [Qemu-devel] [PATCH 0/3] target-arm: cache tbflags in CPUARMState Paolo Bonzini
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 [this message]
2016-11-10 13:37 ` Alex Bennée
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