Re: [RFC PATCH v1 0/2] Avoid rcu_core() if CPU just left guest vcpu

From: Sean Christopherson <seanjc@google.com>
To: Leonardo Bras <leobras@redhat.com>
Cc: "Paul E. McKenney" <paulmck@kernel.org>,
	Paolo Bonzini <pbonzini@redhat.com>,
	 Frederic Weisbecker <frederic@kernel.org>,
	Neeraj Upadhyay <quic_neeraju@quicinc.com>,
	 Joel Fernandes <joel@joelfernandes.org>,
	Josh Triplett <josh@joshtriplett.org>,
	 Boqun Feng <boqun.feng@gmail.com>,
	Steven Rostedt <rostedt@goodmis.org>,
	 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
	Lai Jiangshan <jiangshanlai@gmail.com>,
	 Zqiang <qiang.zhang1211@gmail.com>,
	Marcelo Tosatti <mtosatti@redhat.com>,
	kvm@vger.kernel.org,  linux-kernel@vger.kernel.org,
	rcu@vger.kernel.org
Subject: Re: [RFC PATCH v1 0/2] Avoid rcu_core() if CPU just left guest vcpu
Date: Wed, 8 May 2024 07:01:29 -0700	[thread overview]
Message-ID: <ZjuFuZHKUy7n6-sG@google.com> (raw)
In-Reply-To: <ZjsZVUdmDXZOn10l@LeoBras>

On Wed, May 08, 2024, Leonardo Bras wrote:
> Something just hit me, and maybe I need to propose something more generic.

Yes.  This is what I was trying to get across with my complaints about keying off
of the last VM-Exit time.  It's effectively a broad stroke "this task will likely
be quiescent soon" and so the core concept/functionality belongs in common code,
not KVM.