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Mon, 6 Jul 2026 08:24:06 +0000 (GMT) Message-ID: Date: Mon, 6 Jul 2026 13:54:05 +0530 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: [PATCH v6 12/23] virt: Introduce steal monitor driver To: Yury Norov Cc: linux-kernel@vger.kernel.org, mingo@kernel.org, peterz@infradead.org, juri.lelli@redhat.com, vincent.guittot@linaro.org, yury.norov@gmail.com, kprateek.nayak@amd.com, iii@linux.ibm.com, corbet@lwn.net, tglx@kernel.org, gregkh@linuxfoundation.org, pbonzini@redhat.com, seanjc@google.com, vschneid@redhat.com, huschle@linux.ibm.com, rostedt@goodmis.org, dietmar.eggemann@arm.com, maddy@linux.ibm.com, srikar@linux.ibm.com, hdanton@sina.com, chleroy@kernel.org, vineeth@bitbyteword.org, frederic@kernel.org, arighi@nvidia.com, pauld@redhat.com, christian.loehle@arm.com, tj@kernel.org, tommaso.cucinotta@gmail.com, maz@kernel.org, rafael@kernel.org, rdunlap@infradead.org, kernellwp@gmail.com, linux-doc@vger.kernel.org References: <20260701141654.500125-1-sshegde@linux.ibm.com> <20260701141654.500125-13-sshegde@linux.ibm.com> From: Shrikanth Hegde Content-Language: en-US In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-TM-AS-GCONF: 00 X-Proofpoint-Reinject: loops=2 maxloops=12 X-Proofpoint-GUID: FLNpqZBnB4YYYeIJVWptxWLRCLxg-jBk X-Proofpoint-Spam-Details-Enc: AW1haW4tMjYwNzA2MDA4MyBTYWx0ZWRfX6BAbvGNlB4eW qm1GtqoP28Sn8//t9d84dYfO4LA/COrtwOEgyCqNVrrhiz56dEpohwDGY4ve8BvApVurG9Jd7UR rYhrWDZ1PbnzJmqYrtzhSEjLkx44RNIPR5PbnOOb1EwflJcqDksvC0oonIL66bwT/soYRXRnbQH t9KheSbsCwrMardX0R49puLjwhuuyvqpvyV7ttnnNwDi7+W2DjIOy/frDkIE50GFc+cMo5QqXSA rli/qATIHfk9ysO2/WVOWN6Q5WCJzZaHpqCcHWh9+6BV3ESyHWA9b0Y+DmkAFUg619QGOoARxE6 29YGZm+UpmZeHU6OmCF0J1jppTK4pE4RHeIAC5Ha2GzSXcxpQZt9be8RoDd+I6zIjp6U1q3kAl+ JW3FJzJ5/6GnhNegWGv/P5BYT69sBiaIzhez19F7dxc5yzJ+ReRc2nOQ9i+bM+TdUQpF6UQZzFo GpKDxB4BIoAc3PoMg6Q== X-Proofpoint-ORIG-GUID: A-9P4aFmCtdngnqVd5VoCodHw6Hri8ye X-Authority-Analysis: v=2.4 cv=FqQ1OWrq c=1 sm=1 tr=0 ts=6a4b6632 cx=c_pps a=aDMHemPKRhS1OARIsFnwRA==:117 a=aDMHemPKRhS1OARIsFnwRA==:17 a=IkcTkHD0fZMA:10 a=RAioF0-LDSMA:10 a=VkNPw1HP01LnGYTKEx00:22 a=RnoormkPH1_aCDwRdu11:22 a=U7nrCbtTmkRpXpFmAIza:22 a=uXM6aEYcthE1n8yYxcMA:9 a=QEXdDO2ut3YA:10 X-Proofpoint-Spam-Info: AW1haW4tMjYwNzA2MDA4MyBTYWx0ZWRfXyytUlg5gpSD2 bKBOJSYrfnFuj29Jmrs+D2MfB4+9f2Ll0ztLzOnn4ZT3qXOG5jbqfi4Fcr9NuA0RQVDab7NaMcB 07Onx5GItxUNNU4qSIj61XwKtgSYq1w= X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1143,Hydra:6.1.125,FMLib:17.12.100.49 definitions=2026-07-05_02,2026-07-03_01,2025-10-01_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 adultscore=0 impostorscore=0 clxscore=1015 malwarescore=0 lowpriorityscore=0 priorityscore=1501 bulkscore=0 suspectscore=0 spamscore=0 phishscore=0 classifier=typeunknown authscore=0 authtc= authcc= route=outbound adjust=0 reason=mlx scancount=1 engine=8.22.0-2606150000 definitions=main-2607060083 On 7/3/26 11:57 PM, Yury Norov wrote: > On Fri, Jul 03, 2026 at 02:20:32PM -0400, Yury Norov wrote: >> On Wed, Jul 01, 2026 at 07:46:43PM +0530, Shrikanth Hegde wrote: >>> Introduce a new driver in virt named steal_monitor. This driver >>> will compute the steal time and drive the policy decisions of preferred >>> CPU state. >>> >>> More on it can be found in the Documentation/driver-api/steal-monitor.rst >>> Introduce the skeleton code first. >>> >>> There is no new kconfig. It depends on CONFIG_PREFERRED_CPU. >>> - If CONFIG_PREFERRED_CPU=y, it gets compiled as a module. It is not >>> loaded by default. > > What if I've got my own monitor, and don't need this one? Please add a > way to not compile it, even if CONFIG_PREFERRED_CPU is enabled. > You mean make a new config like VIRT_MONITOR depend on CONFIG_PREFERRED_CPU and make it as default n? Can we defer this until such a new monitor is needed? We will in state where CONFIG_PREFERRED_CPU=y & VIRT_MONITOR=n.