From: Sean Christopherson <seanjc@google.com>
To: 76824143@qq.com
Cc: pbonzini@redhat.com, kvm@vger.kernel.org,
zhanghao <zhanghao1@kylinos.cn>
Subject: Re: [PATCH 3/3] KVM: x86: Use dynamic try count based on vCPU count
Date: Tue, 17 Feb 2026 08:21:02 -0800 [thread overview]
Message-ID: <aZSVbjPhURBe1Rj0@google.com> (raw)
In-Reply-To: <tencent_EAB2053E04BF4C7F996CEC61331C23154007@qq.com>
On Sun, Feb 15, 2026, 76824143@qq.com wrote:
> From: zhanghao <zhanghao1@kylinos.cn>
>
> Replace the fixed try count (3) with a dynamic calculation based
> on the number of online vCPUs. This allows larger VMs to try more
> candidates before giving up, while keeping small VMs efficient.
>
> Formula: clamp(ilog2(nr_vcpus + 1), 3, 10)
> - 4 vCPUs: try = 3
> - 64 vCPUs: try = 6
> - 256 vCPUs: try = 8
Why do larger VMs warrant more attempts though? E.g. what are practical downsides
of trying min(nr_vcpus - 1, 8) times?
next prev parent reply other threads:[~2026-02-17 16:21 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20260215140402.24659-1-76824143@qq.com>
2026-02-15 14:04 ` [PATCH 1/3] KVM: x86: Enhance kvm_vcpu_eligible_for_directed_yield to detect golden targets 76824143
2026-02-17 15:37 ` Sean Christopherson
2026-02-15 14:04 ` [PATCH 2/3] KVM: x86: Skip IN_GUEST_MODE vCPUs in kvm_vcpu_on_spin main loop 76824143
2026-02-17 15:41 ` Sean Christopherson
2026-03-12 5:57 ` zhanghao
2026-03-13 1:02 ` Sean Christopherson
2026-03-19 8:40 ` zhanghao
2026-02-15 14:04 ` [PATCH 3/3] KVM: x86: Use dynamic try count based on vCPU count 76824143
2026-02-17 16:21 ` Sean Christopherson [this message]
2026-03-12 6:24 ` zhanghao
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=aZSVbjPhURBe1Rj0@google.com \
--to=seanjc@google.com \
--cc=76824143@qq.com \
--cc=kvm@vger.kernel.org \
--cc=pbonzini@redhat.com \
--cc=zhanghao1@kylinos.cn \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.