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Mon, 20 Oct 2025 08:05:40 -0700 (PDT) Received: from [192.168.10.27] ([151.61.22.175]) by smtp.googlemail.com with ESMTPSA id 5b1f17b1804b1-4710ed4b47fsm117263495e9.4.2025.10.20.08.05.38 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 20 Oct 2025 08:05:39 -0700 (PDT) Message-ID: Date: Mon, 20 Oct 2025 17:05:37 +0200 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [RFC PATCH v3 00/10] paravirt CPUs and push task for less vCPU preemption To: Sean Christopherson , Shrikanth Hegde Cc: mingo@redhat.com, peterz@infradead.org, juri.lelli@redhat.com, vincent.guittot@linaro.org, tglx@linutronix.de, yury.norov@gmail.com, maddy@linux.ibm.com, linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, gregkh@linuxfoundation.org, vschneid@redhat.com, iii@linux.ibm.com, huschle@linux.ibm.com, rostedt@goodmis.org, dietmar.eggemann@arm.com, vineeth@bitbyteword.org, jgross@suse.com References: <20250910174210.1969750-1-sshegde@linux.ibm.com> From: Paolo Bonzini Content-Language: en-US Autocrypt: addr=pbonzini@redhat.com; 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charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 10/20/25 16:32, Sean Christopherson wrote: > : Till the hint from underlying hypervisor arrives, another idea is to > : approximate the hint from steal time. I think this is the first thing to look at. Perhaps single_task_running() can be exposed in the x86 steal time data structure, and in fact even in the rseq data for non-VM usecases? This is not specific to VMs and I'd like the steal time implementation to follow the footsteps of rseq rather than the opposite. Paolo