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Message-ID: <3fa9b9675e381dc483c4656d86253955dcb96f2e.camel@linux.intel.com>
Subject: Re: [PATCH] sched/topology: Align group flags when removing
 degenerate domain
From:   Tim Chen <tim.c.chen@linux.intel.com>
To:     Chen Yu <yu.c.chen@intel.com>,
        Peter Zijlstra <peterz@infradead.org>,
        Juri Lelli <juri.lelli@redhat.com>,
        Vincent Guittot <vincent.guittot@linaro.org>,
        Ingo Molnar <mingo@redhat.com>
Cc:     Ricardo Neri <ricardo.neri@intel.com>,
        Tim Chen <tim.c.chen@intel.com>,
        Yicong Yang <yangyicong@huawei.com>,
        linux-kernel@vger.kernel.org
Date:   Wed, 12 Jul 2023 11:36:26 -0700
In-Reply-To: <20230713013133.2314153-1-yu.c.chen@intel.com>
References: <20230713013133.2314153-1-yu.c.chen@intel.com>
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On Thu, 2023-07-13 at 09:31 +0800, Chen Yu wrote:
> The flags of the child of a given scheduling domain are used to initializ=
e
> the flags of its scheduling groups. When the child of a scheduling domain
> is degenerated, the flags of its local scheduling group need to be update=
d
> to align with the flags of its new child domain.
>=20
> The flag SD_SHARE_CPUCAPACITY was aligned in
> Commit bf2dc42d6beb ("sched/topology: Propagate SMT flags when removing d=
egenerate domain").
> Further generalize this alignment so other flags can be used later, such =
as
> in cluster-based task wakeup. [1]
>=20
> Link: https://lore.kernel.org/lkml/20230530115527.GC156198@hirez.programm=
ing.kicks-ass.net #1
> Suggested-by: Ricardo Neri <ricardo.neri@intel.com>
> Reported-by: Yicong Yang <yangyicong@huawei.com>
> Closes: https://lore.kernel.org/lkml/ce714341-af58-2522-69a8-321f02c82893=
@huawei.com/
> Signed-off-by: Chen Yu <yu.c.chen@intel.com>
> ---
>  kernel/sched/topology.c | 3 +--
>  1 file changed, 1 insertion(+), 2 deletions(-)
>=20
> diff --git a/kernel/sched/topology.c b/kernel/sched/topology.c
> index d3a3b2646ec4..ff02d7deec0c 100644
> --- a/kernel/sched/topology.c
> +++ b/kernel/sched/topology.c
> @@ -722,8 +722,7 @@ cpu_attach_domain(struct sched_domain *sd, struct roo=
t_domain *rd, int cpu)
> =20
>  			if (parent->parent) {
>  				parent->parent->child =3D tmp;
> -				if (tmp->flags & SD_SHARE_CPUCAPACITY)
> -					parent->parent->groups->flags |=3D SD_SHARE_CPUCAPACITY;
> +				parent->parent->groups->flags =3D tmp->flags;
>  			}
> =20
>  			/*

Reviewed-by: Tim Chen <tim.c.chen@linux.intel.com>