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From:   Valentin Schneider <valentin.schneider@arm.com>
To:     Peter Zijlstra <peterz@infradead.org>, mingo@kernel.org,
        mgorman@suse.de, juri.lelli@redhat.com, vincent.guittot@linaro.org,
        dietmar.eggemann@arm.com, rostedt@goodmis.org, bsegall@google.com,
        bristot@redhat.com, joshdon@google.com
Cc:     linux-kernel@vger.kernel.org, peterz@infradead.org, greg@kroah.com,
        linux@rasmusvillemoes.dk
Subject: Re: [PATCH v2 7/9] sched,debug: Convert sysctl sched_domains to debugfs
In-Reply-To: <20210412102001.485107586@infradead.org>
References: <20210412101421.609526370@infradead.org> <20210412102001.485107586@infradead.org>
Date:   Tue, 13 Apr 2021 15:55:15 +0100
Message-ID: <87lf9mmdyk.mognet@arm.com>
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On 12/04/21 12:14, Peter Zijlstra wrote:
> Stop polluting sysctl, move to debugfs for SCHED_DEBUG stuff.
>
> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
> Reviewed-by: Dietmar Eggemann <dietmar.eggemann@arm.com>

On my Juno (2+4 big.LITTLE), sys/kernel/debug/sched/domains/ is now empty.

I think that's because of unregister_sched_domain_sysctl() -
debugfs_remove() is recursive, and I do get a case where we rebuild the
domains but no CPU has been added or removed (we rebuild the domains when
cpufreq kicks in, it's part of the big.LITTLE ponies).

Do we actually still need that unregister? From a brief glance it looks
like we could throw it out.