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Message-ID: <ec2fdae5f574e407308ba7746fe18a69542b7c1d.camel@linux.intel.com>
Subject: Re: [Patch v3 1/6] sched/fair: Determine active load balance for
 SMT sched groups
From:   Tim Chen <tim.c.chen@linux.intel.com>
To:     Shrikanth Hegde <sshegde@linux.vnet.ibm.com>
Cc:     Juri Lelli <juri.lelli@redhat.com>,
        Vincent Guittot <vincent.guittot@linaro.org>,
        Ricardo Neri <ricardo.neri@intel.com>,
        "Ravi V . Shankar" <ravi.v.shankar@intel.com>,
        Ben Segall <bsegall@google.com>,
        Daniel Bristot de Oliveira <bristot@redhat.com>,
        Dietmar Eggemann <dietmar.eggemann@arm.com>,
        Len Brown <len.brown@intel.com>, Mel Gorman <mgorman@suse.de>,
        "Rafael J . Wysocki" <rafael.j.wysocki@intel.com>,
        Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>,
        Steven Rostedt <rostedt@goodmis.org>,
        Valentin Schneider <vschneid@redhat.com>,
        Ionela Voinescu <ionela.voinescu@arm.com>, x86@kernel.org,
        linux-kernel@vger.kernel.org,
        Srikar Dronamraju <srikar@linux.vnet.ibm.com>,
        naveen.n.rao@linux.vnet.ibm.com,
        Yicong Yang <yangyicong@hisilicon.com>,
        Barry Song <v-songbaohua@oppo.com>,
        Chen Yu <yu.c.chen@intel.com>, Hillf Danton <hdanton@sina.com>,
        Peter Zijlstra <peterz@infradead.org>
Date:   Sat, 15 Jul 2023 11:25:58 -0700
In-Reply-To: <a399af19aa8e1291558724509a1de2f52b3bad0a.camel@linux.intel.com>
References: <cover.1688770494.git.tim.c.chen@linux.intel.com>
         <e24f35d142308790f69be65930b82794ef6658a2.1688770494.git.tim.c.chen@linux.intel.com>
         <165778ce-7b8f-1966-af02-90ef481455b9@linux.vnet.ibm.com>
         <a399af19aa8e1291558724509a1de2f52b3bad0a.camel@linux.intel.com>
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>=20
> diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
> index 294a662c9410..3fc8d3a3bd22 100644
> --- a/kernel/sched/fair.c
> +++ b/kernel/sched/fair.c
> @@ -9588,6 +9588,17 @@ static bool update_sd_pick_busiest(struct lb_env *=
env,
>                 break;
> =20
>         case group_smt_balance:
> +               /* no idle cpus on both groups handled by group_fully_bus=
y below */
> +               if (sgs->idle_cpus !=3D 0 || busiest->idle_cpus !=3D 0) {
> +                       if (sgs->idle_cpus > busiest->idle_cpus)
> +                               return false;
> +                       if (sgs->idle_cpus < busiest->idle_cpus)
> +                               return true;
> +                       if (sgs->sum_nr_running <=3D busiest_sum_nr_runni=
ng)

typo: should be busiest->sum->nr_running

> +                               return false;
> +                       else
> +                               return true;
> +               }
>=20

Tim