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X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: rhHvx1n4C80uufChkYM1wLczgqvCVQg8Liq4YEg1UqHPrfqhRfq6AT09qP/osiIWEywnw7xdrzZeQhML7e+hgWmk+qrlzkPs8NadamXcjE/7ac1/6UYLpMH5WGWmBZnA7vT6VCd9F2aTYXi+5pOVlMoanGJtyJGqnBOAJNmgpII+bNy8KGVuAMKpf0rfgOu743YokUNz+fUHknGq2B8IqTHO9NUFH9q4BlVBYx/1dkR2pOmgaeJLvCqTx3Ka9S2VQVXX+X8lHihrtuknwvdWapSfF40H+fNCaX2lOXTGpMA+e5UcZRQl7vkotUsow55O46PIPZVeVyKRGvsr4vCvNb9hju/ypawSwVvDQLZlnuvMgEnmDZQTaSGPFWsqwgr3doXx8GNe+f0GVNGNxgV74Ee4lRsmWVbagrPzJFY8iBXg6eI90f4IJUPTfLzVlsoK X-OriginatorOrg: amd.com X-MS-Exchange-CrossTenant-OriginalArrivalTime: 20 Mar 2026 03:37:51.2219 (UTC) X-MS-Exchange-CrossTenant-Network-Message-Id: 72a24eb1-99de-452c-3e02-08de86321044 X-MS-Exchange-CrossTenant-Id: 3dd8961f-e488-4e60-8e11-a82d994e183d X-MS-Exchange-CrossTenant-OriginalAttributedTenantConnectingIp: TenantId=3dd8961f-e488-4e60-8e11-a82d994e183d;Ip=[165.204.84.17];Helo=[satlexmb08.amd.com] X-MS-Exchange-CrossTenant-AuthSource: BL6PEPF00020E66.namprd04.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Anonymous X-MS-Exchange-CrossTenant-FromEntityHeader: HybridOnPrem X-MS-Exchange-Transport-CrossTenantHeadersStamped: SJ2PR12MB9088 Hello Shrikanth, On 3/19/2026 12:23 PM, Shrikanth Hegde wrote: > diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c > index b19aeaa51ebc..02cca2c7a98d 100644 > --- a/kernel/sched/fair.c > +++ b/kernel/sched/fair.c > @@ -7392,6 +7392,7 @@ static inline unsigned int cfs_h_nr_delayed(struct rq *rq) > static DEFINE_PER_CPU(cpumask_var_t, load_balance_mask); > static DEFINE_PER_CPU(cpumask_var_t, select_rq_mask); > static DEFINE_PER_CPU(cpumask_var_t, should_we_balance_tmpmask); > +static DEFINE_PER_CPU(cpumask_var_t, kick_ilb_tmpmask); nit. We can rename and reuse select_rq_mask. Wakeups happen with IRQs disabled and kick happens from the hrtimer handler so it should be safe to reuse that and save some space. Thoughts? [..snip..] > @@ -12715,27 +12716,41 @@ static void nohz_balancer_kick(struct rq *rq) > */ > nohz_balance_exit_idle(rq); > > + /* ILB considers only HK_TYPE_KERNEL_NOISE housekeeping CPUs */ > + > if (READ_ONCE(nohz.has_blocked_load) && > - time_after(now, READ_ONCE(nohz.next_blocked))) > + time_after(now, READ_ONCE(nohz.next_blocked))) { > flags = NOHZ_STATS_KICK; > + cpumask_and(ilb_cpus, nohz.idle_cpus_mask, > + housekeeping_cpumask(HK_TYPE_KERNEL_NOISE)); > + } > > /* > - * Most of the time system is not 100% busy. i.e nohz.nr_cpus > 0 > - * Skip the read if time is not due. > + * Most of the time system is not 100% busy. i.e there are idle > + * housekeeping CPUs. > + * > + * So, Skip the reading idle_cpus_mask if time is not due. > * > * If none are in tickless mode, there maybe a narrow window > * (28 jiffies, HZ=1000) 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 check (idle_cpus_mask & HK_TYPE_KERNEL_NOISE) > + * only if time is due. > + * > */ > if (time_before(now, nohz.next_balance)) > goto out; > > + /* Avoid the double computation */ > + if (flags != NOHZ_STATS_KICK) > + cpumask_and(ilb_cpus, nohz.idle_cpus_mask, > + housekeeping_cpumask(HK_TYPE_KERNEL_NOISE)); > + > /* > * None are in tickless mode and hence no need for NOHZ idle load > * balancing > */ > - if (unlikely(cpumask_empty(nohz.idle_cpus_mask))) > + if (unlikely(cpumask_empty(ilb_cpus))) > return; We can just use the return value from the previous cpumask_and() for this and save on another cpumask iteration. > > if (rq->nr_running >= 2) { -- Thanks and Regards, Prateek