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Thu, 19 Mar 2026 06:53:30 +0000 (GMT) From: Shrikanth Hegde To: mingo@kernel.org, peterz@infradead.org, vincent.guittot@linaro.org, linux-kernel@vger.kernel.org Cc: sshegde@linux.ibm.com, kprateek.nayak@amd.com, juri.lelli@redhat.com, vschneid@redhat.com, tglx@linutronix.de, dietmar.eggemann@arm.com, frederic@kernel.org, longman@redhat.com Subject: [PATCH 0/2] sched/fair: Minor improvements while triggering idle load balance Date: Thu, 19 Mar 2026 12:23:12 +0530 Message-ID: <20260319065314.343932-1-sshegde@linux.ibm.com> X-Mailer: git-send-email 2.51.0 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-TM-AS-GCONF: 00 X-Proofpoint-ORIG-GUID: -oGW3z_xT4NLYOa68ggPo3InchOY0XLs X-Proofpoint-GUID: -oGW3z_xT4NLYOa68ggPo3InchOY0XLs X-Authority-Analysis: v=2.4 cv=KYnfcAYD c=1 sm=1 tr=0 ts=69bb9d70 cx=c_pps a=GFwsV6G8L6GxiO2Y/PsHdQ==:117 a=GFwsV6G8L6GxiO2Y/PsHdQ==:17 a=Yq5XynenixoA:10 a=VkNPw1HP01LnGYTKEx00:22 a=RnoormkPH1_aCDwRdu11:22 a=iQ6ETzBq9ecOQQE5vZCe:22 a=lS1G1kBLjldKZ4bnmFoA:9 a=zZCYzV9kfG8A:10 X-Proofpoint-Spam-Details-Enc: AW1haW4tMjYwMzE5MDA1MSBTYWx0ZWRfX53LXzeGUylIa jry2iRCUtKT/rZCV6sg7ET3OF+qf5K4SKbdIY/k0rHRgsUoBiGNb0IZcMrTBi3u8j9fJB1PAky0 5hTuO6kVIq2cOiINCKnahjh4JSdcg+bb/+BnMtEfERv1qlhnnx7DKnhe8aRX0Hlkx65X6b9pSRy AQUg5+eCh8vw2tpT7qGx8jC+97XLWx8ByGP1cpTYSuYPa5BVxyhCzhezn/F/lLonRowTF2U2xIt a5eDiiLtyMyAwfC07mxPMgsoABffnHFuctYNAvVw2OgpastQQFqC8sp/2rcaOKTJ4ZvksbxByuz +ovfx0/EZch1uk9dwszrYUyLOuHDcxOGkSOkU+edD/38IunVHVOLHKhIe03V21sAqis5ODd3Jxa ZwIkXxhVpl+I0emHp/6d9xrPznx5v4YTFn+AMnVjsb9UJ/QzLTNIvr7X6fzaUSRTY7zYFTBD54o efhVASwtpm9UPklLlPw== X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1143,Hydra:6.1.51,FMLib:17.12.100.49 definitions=2026-03-19_01,2026-03-17_02,2025-10-01_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 phishscore=0 lowpriorityscore=0 priorityscore=1501 suspectscore=0 bulkscore=0 spamscore=0 impostorscore=0 malwarescore=0 adultscore=0 clxscore=1011 classifier=typeunknown authscore=0 authtc= authcc= route=outbound adjust=0 reason=mlx scancount=1 engine=8.22.0-2603050001 definitions=main-2603190051 While reading the code, noticed that I hadn't updated the comments around nohz.nr_cpus which are stale now. While going through that code again, saw these minor improvements that could be done. Since these are fastpaths, even a little would help. No functional change intended. It would help a bit when one runs with nohz_full. The old code would bail out in find_new_ilb() when no eligible housekeeping idle CPU exists; this one just avoids doing the extra checks by making the same decision earlier. It is quite difficult to accurately predict that dance nohz.next_balance and nohz.next_blocked, So do the same check for both. Avoid the duplication if set already. Didn't see a better way. Shrikanth Hegde (2): sched/fair: consider hk_mask early in triggering ilb sched/fair: get this cpu once in find_new_ilb kernel/sched/fair.c | 49 ++++++++++++++++++++++++++++++--------------- 1 file changed, 33 insertions(+), 16 deletions(-) -- 2.43.0