linux-arm-kernel.lists.infradead.org archive mirror
 help / color / mirror / Atom feed
From: Oliver Upton <oliver.upton@linux.dev>
To: Sean Christopherson <seanjc@google.com>
Cc: Marc Zyngier <maz@kernel.org>,
	Paolo Bonzini <pbonzini@redhat.com>,
	linux-arm-kernel@lists.infradead.org, kvmarm@lists.linux.dev,
	kvm@vger.kernel.org, linux-kernel@vger.kernel.org,
	Steve Rutherford <srutherford@google.com>
Subject: Re: [PATCH 0/2] KVM: Protect vCPU's PID with a rwlock
Date: Tue, 6 Aug 2024 15:59:26 -0700	[thread overview]
Message-ID: <ZrKqzrPF_y4momna@linux.dev> (raw)
In-Reply-To: <20240802200136.329973-1-seanjc@google.com>

On Fri, Aug 02, 2024 at 01:01:34PM -0700, Sean Christopherson wrote:
> Protect vcpu->pid with a rwlock instead of RCU, so that running a vCPU
> with a different task doesn't require a full RCU synchronization, which
> can introduce a non-trivial amount of jitter, especially on large systems.
> 
> I've had this mini-series sitting around for ~2 years, pretty much as-is.
> I could have sworn past me thought there was a flaw in using a rwlock, and
> so I never posted it, but for the life of me I can't think of any issues.
> 
> Extra eyeballs would be much appreciated.

Besides the nitpicks:

Acked-by: Oliver Upton <oliver.upton@linux.dev>

-- 
Thanks,
Oliver


  parent reply	other threads:[~2024-08-06 23:00 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-08-02 20:01 [PATCH 0/2] KVM: Protect vCPU's PID with a rwlock Sean Christopherson
2024-08-02 20:01 ` [PATCH 1/2] KVM: Return '0' directly when there's no task to yield to Sean Christopherson
2024-08-02 20:01 ` [PATCH 2/2] KVM: Protect vCPU's "last run PID" with rwlock, not RCU Sean Christopherson
2024-08-02 20:28   ` Steve Rutherford
2024-08-02 20:51     ` Sean Christopherson
2024-08-02 21:27   ` Steve Rutherford
2024-08-06 22:58   ` Oliver Upton
2024-08-06 23:59     ` Sean Christopherson
2024-08-09 18:05       ` Oliver Upton
2024-08-13  2:05         ` Sean Christopherson
2024-08-06 22:59 ` Oliver Upton [this message]
2024-10-31 19:51 ` [PATCH 0/2] KVM: Protect vCPU's PID with a rwlock Sean Christopherson

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=ZrKqzrPF_y4momna@linux.dev \
    --to=oliver.upton@linux.dev \
    --cc=kvm@vger.kernel.org \
    --cc=kvmarm@lists.linux.dev \
    --cc=linux-arm-kernel@lists.infradead.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=maz@kernel.org \
    --cc=pbonzini@redhat.com \
    --cc=seanjc@google.com \
    --cc=srutherford@google.com \
    /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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).