Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
Date:   Tue, 2 Jul 2019 18:23:12 +0200
From:   Peter Zijlstra <peterz@infradead.org>
To:     subhra mazumdar <subhra.mazumdar@oracle.com>
Cc:     linux-kernel@vger.kernel.org, mingo@redhat.com, tglx@linutronix.de,
        prakash.sangappa@oracle.com, dhaval.giani@oracle.com,
        daniel.lezcano@linaro.org, vincent.guittot@linaro.org,
        viresh.kumar@linaro.org, tim.c.chen@linux.intel.com,
        mgorman@techsingularity.net
Subject: Re: [RFC PATCH 1/3] sched: Introduce new interface for scheduler
 soft affinity
Message-ID: <20190702162312.GY3436@hirez.programming.kicks-ass.net>
References: <20190626224718.21973-1-subhra.mazumdar@oracle.com>
 <20190626224718.21973-2-subhra.mazumdar@oracle.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <20190626224718.21973-2-subhra.mazumdar@oracle.com>
User-Agent: Mutt/1.10.1 (2018-07-13)
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

On Wed, Jun 26, 2019 at 03:47:16PM -0700, subhra mazumdar wrote:
> diff --git a/include/linux/sched.h b/include/linux/sched.h
> index 1183741..b863fa8 100644
> --- a/include/linux/sched.h
> +++ b/include/linux/sched.h
> @@ -652,6 +652,8 @@ struct task_struct {
>  	unsigned int			policy;
>  	int				nr_cpus_allowed;
>  	cpumask_t			cpus_allowed;

You're patching dead code, that no longer exists.

> +	cpumask_t			cpus_preferred;
> +	bool				affinity_unequal;

Urgh, no. cpumask_t is an abomination and having one of them is already
unfortunate, having two is really not sane, esp. since for 99% of the
tasks they'll be exactly the same.

Why not add cpus_ptr_soft or something like that, and have it point at
cpus_mask by default, and when it needs to not be the same, allocate a
cpumask for it. That also gets rid of that unequal thing.