From: Paolo Bonzini <pbonzini@redhat.com>
To: Marc Zyngier <maz@kernel.org>, Jing Zhang <jingzhangos@google.com>
Cc: KVM <kvm@vger.kernel.org>,
Sean Christopherson <seanjc@google.com>,
Peter Shier <pshier@google.com>,
David Matlack <dmatlack@google.com>,
Will Deacon <will@kernel.org>,
KVMARM <kvmarm@lists.cs.columbia.edu>
Subject: Re: [PATCH v1 3/3] KVM: arm64: Add histogram stats for handling time of arch specific exit reasons
Date: Wed, 22 Sep 2021 17:37:35 +0200 [thread overview]
Message-ID: <d16ecbd2-2bc9-2691-a21d-aef4e6f007b9@redhat.com> (raw)
In-Reply-To: <87czp0voqg.wl-maz@kernel.org>
On 22/09/21 13:22, Marc Zyngier wrote:
> Frankly, this is a job for BPF and the tracing subsystem, not for some
> hardcoded syndrome accounting. It would allow to extract meaningful
> information, prevent bloat, and crucially make it optional. Even empty
> trace points like the ones used in the scheduler would be infinitely
> better than this (load your own module that hooks into these trace
> points, expose the data you want, any way you want).
I agree. I had left out for later the similar series you had for x86,
but I felt the same as Marc; even just counting the number of
occurrences of each exit reason is a nontrivial amount of memory to
spend on each vCPU.
Paolo
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next prev parent reply other threads:[~2021-09-22 15:37 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-09-22 1:08 [PATCH v1 1/3] KVM: arm64: Add arch specific exit reasons Jing Zhang
2021-09-22 1:08 ` [PATCH v1 2/3] KVM: arm64: Add counter stats for " Jing Zhang
2021-09-22 1:08 ` [PATCH v1 3/3] KVM: arm64: Add histogram stats for handling time of " Jing Zhang
2021-09-22 11:22 ` Marc Zyngier
2021-09-22 15:37 ` Paolo Bonzini [this message]
2021-09-22 16:09 ` Jing Zhang
2021-09-22 18:13 ` Sean Christopherson
2021-09-22 18:53 ` Marc Zyngier
2021-09-22 23:22 ` David Matlack
2021-09-30 14:04 ` Marc Zyngier
2021-09-30 18:05 ` Sean Christopherson
2021-09-23 6:36 ` Paolo Bonzini
2021-09-23 7:45 ` Marc Zyngier
2021-09-23 9:44 ` Paolo Bonzini
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