From: Marc Zyngier <maz@kernel.org>
To: Jing Zhang <jingzhangos@google.com>
Cc: catalin.marinas@arm.com, linux-arm-kernel@lists.infradead.org,
will@kernel.org, kvmarm@lists.cs.columbia.edu
Subject: Re: [PATCH] KVM: arm64: Remove redundant check for S2FWB
Date: Fri, 05 Feb 2021 17:24:06 +0000 [thread overview]
Message-ID: <e34480715d3d5e13e5238195d596feda@kernel.org> (raw)
In-Reply-To: <20210205044403.1559010-1-jingzhangos@google.com>
Hi Jing,
On 2021-02-05 04:44, Jing Zhang wrote:
> Remove redundant check for CPU feature S2FWB in dcache flush code
> to save some CPU cycles for every memslot flush and unmapping.
What CPU cycles? This is only a static branch. Can you actually
measure the overhead? What does it represent in the face of
a full memslot unmapping?
Thanks,
M.
--
Jazz is not dead. It just smells funny...
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WARNING: multiple messages have this Message-ID (diff)
From: Marc Zyngier <maz@kernel.org>
To: Jing Zhang <jingzhangos@google.com>
Cc: suzuki.poulose@arm.com, catalin.marinas@arm.com,
qperret@google.com, james.morse@arm.com,
linux-arm-kernel@lists.infradead.org, will@kernel.org,
kvmarm@lists.cs.columbia.edu, julien.thierry.kdev@gmail.com
Subject: Re: [PATCH] KVM: arm64: Remove redundant check for S2FWB
Date: Fri, 05 Feb 2021 17:24:06 +0000 [thread overview]
Message-ID: <e34480715d3d5e13e5238195d596feda@kernel.org> (raw)
In-Reply-To: <20210205044403.1559010-1-jingzhangos@google.com>
Hi Jing,
On 2021-02-05 04:44, Jing Zhang wrote:
> Remove redundant check for CPU feature S2FWB in dcache flush code
> to save some CPU cycles for every memslot flush and unmapping.
What CPU cycles? This is only a static branch. Can you actually
measure the overhead? What does it represent in the face of
a full memslot unmapping?
Thanks,
M.
--
Jazz is not dead. It just smells funny...
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply other threads:[~2021-02-05 17:24 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-02-05 4:44 [PATCH] KVM: arm64: Remove redundant check for S2FWB Jing Zhang
2021-02-05 4:44 ` Jing Zhang
2021-02-05 17:24 ` Marc Zyngier [this message]
2021-02-05 17:24 ` Marc Zyngier
2021-02-05 18:56 ` Jing Zhang
2021-02-05 18:56 ` Jing Zhang
2021-03-08 16:49 ` Will Deacon
2021-03-08 16:49 ` Will Deacon
2021-03-08 18:43 ` Jing Zhang
2021-03-08 18:43 ` Jing Zhang
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