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Mon, 23 Mar 2026 05:29:11 +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, rostedt@goodmis.org, dietmar.eggemann@arm.com Subject: [PATCH] sched/fair: Fix stale comments around nohz.nr_cpus Date: Mon, 23 Mar 2026 10:59:09 +0530 Message-ID: <20260323052909.561337-1-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: quoted-printable X-TM-AS-GCONF: 00 X-Proofpoint-ORIG-GUID: QJa2hRP77m8uc6Wn07MyJlRtjSkAXLmz X-Proofpoint-Spam-Details-Enc: AW1haW4tMjYwMzIzMDAzOCBTYWx0ZWRfX4dbgjDBDc2Wb ZV30MQfMYUq3dQyJwMdHQugF6tDjJLkDAVuIt3haV6C866e59AxQo+k0y4y9pCgC9/ipC56EQpJ CYKhIsGEWwNdl8zvEZ1kyaTB7MTKl81ihboYaKHd+I3EtsfBKPP4iCcI8Er3Uo2aAaOkobZmfKB g5+cCBSxc6rSsAhIgTMYl4y7EXCjJS6NAxWDluK3zItIgr9NCLIdpaUaobp4T+HkxVVsfChsm5z idUTGsiTVpoWoeEXHiMl3Vf+NHxDNA0m37l0VaahqjqwN6xdCwqTQoBAu7FHtz4fL+oNXUd7Om3 8duf5pFXLBydMsavZbpaaUtLRd6mTl2Rt2IJc3c/S2IJTOo12EiYcSuOzyJRkd++Zga57+ljMH8 r5Wud3Td51FU+jNShr92z7rwbqb1Qu/mRGVukVkpqc9K0eaCBONQvdi2+JKnAr657wWheMLD0Rg WKqk020ibKKtfvb7ISA== X-Authority-Analysis: v=2.4 cv=bLEb4f+Z c=1 sm=1 tr=0 ts=69c0cfac cx=c_pps a=5BHTudwdYE3Te8bg5FgnPg==:117 a=5BHTudwdYE3Te8bg5FgnPg==:17 a=Yq5XynenixoA:10 a=VkNPw1HP01LnGYTKEx00:22 a=RnoormkPH1_aCDwRdu11:22 a=iQ6ETzBq9ecOQQE5vZCe:22 a=VwQbUJbxAAAA:8 a=VnNF1IyMAAAA:8 a=UXmtFdlNUylmFvF1gDkA:9 X-Proofpoint-GUID: QJa2hRP77m8uc6Wn07MyJlRtjSkAXLmz 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=2026-03-23_01,2026-03-20_02,2025-10-01_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 spamscore=0 adultscore=0 clxscore=1015 phishscore=0 impostorscore=0 malwarescore=0 lowpriorityscore=0 suspectscore=0 bulkscore=0 priorityscore=1501 classifier=typeunknown authscore=0 authtc= authcc= route=outbound adjust=0 reason=mlx scancount=1 engine=8.22.0-2603050001 definitions=main-2603230038 Content-Type: text/plain; charset="utf-8" nohz.nr_cpus has been removed. Update those stale comments around it. Fixes: 5d86d542f68f ("sched/fair: Remove nohz.nr_cpus and use weight of cpu= mask instead") Signed-off-by: Shrikanth Hegde Reviewed-by: Valentin Schneider --- Broke it off from v1, since that would need a larger rework. v1: https://lore.kernel.org/all/20260319065314.343932-1-sshegde@linux.ibm.c= om/ kernel/sched/fair.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index b19aeaa51ebc..a24a7cf0fc1d 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -12720,13 +12720,14 @@ static void nohz_balancer_kick(struct rq *rq) flags =3D NOHZ_STATS_KICK; =20 /* - * Most of the time system is not 100% busy. i.e nohz.nr_cpus > 0 + * Most of the time system is not 100% busy. i.e number of CPUs in + * nohz.idle_cpus_mask > 0 * Skip the read if time is not due. * * If none are in tickless mode, there maybe a narrow window * (28 jiffies, HZ=3D1000) where flags maybe set and kick_ilb called. * But idle load balancing is not done as find_new_ilb fails. - * That's very rare. So read nohz.nr_cpus only if time is due. + * That's very rare. So read nohz.idle_cpus_mask only if time is due. */ if (time_before(now, nohz.next_balance)) goto out; --=20 2.47.3