Subject: Re: [PATCH v4 6/7] sched: add function nr_running_cpu to expose
 number of tasks running on cpu
From: Tim Chen <tim.c.chen@linux.intel.com>
To: tkhai@yandex.ru
Cc: Herbert Xu <herbert@gondor.apana.org.au>, "H. Peter Anvin" <hpa@zytor.com>,
        "David S.Miller" <davem@davemloft.net>,
        Peter Zijlstra <peterz@infradead.org>, Ingo Molnar <mingo@kernel.org>,
        Chandramouli Narayanan <mouli@linux.intel.com>,
        Vinodh Gopal <vinodh.gopal@intel.com>,
        James Guilford <james.guilford@intel.com>,
        Wajdi Feghali <wajdi.k.feghali@intel.com>,
        Jussi Kivilinna <jussi.kivilinna@iki.fi>, linux-crypto@vger.kernel.org,
        linux-kernel@vger.kernel.org
In-Reply-To: <53C0FF16.40902@yandex.ru>
References: <cover.1405074379.git.tim.c.chen@linux.intel.com>
	 <1405110784.2970.655.camel@schen9-DESK>  <53C0FF16.40902@yandex.ru>
Content-Type: text/plain; charset="UTF-8"
Date: Mon, 14 Jul 2014 10:51:31 -0700
Message-ID: <1405360291.2970.702.camel@schen9-DESK>
Mime-Version: 1.0
Content-Transfer-Encoding: 7bit
Sender: linux-kernel-owner@vger.kernel.org

On Sat, 2014-07-12 at 13:25 +0400, Kirill Tkhai wrote:

> >  
> > +unsigned long nr_running_cpu(int cpu)
> > +{
> > +	if (cpumask_test_cpu(cpu, cpu_online_mask))
> > +		return cpu_rq(cpu)->nr_running;
> > +	else
> > +		return 0;
> > +}
> > +
> 
> Offline cpu should have nr_running equal to 0. We park last
> enqueued thread (migration_thread) at the end of take_cpu_down().
> 
> So, it's enough to return cpu_rq(cpu)->nr_running.

Thanks.  This seems reasonable.

Tim

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/