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Date: Tue, 24 Apr 2018 14:47:12 +0200
From: Peter Zijlstra <peterz@infradead.org>
To: subhra mazumdar <subhra.mazumdar@oracle.com>
Cc: linux-kernel@vger.kernel.org, mingo@redhat.com,
        daniel.lezcano@linaro.org, steven.sistare@oracle.com,
        dhaval.giani@oracle.com, rohit.k.jain@oracle.com
Subject: Re: [PATCH 2/3] sched: introduce per-cpu var next_cpu to track
 search limit
Message-ID: <20180424124712.GR4082@hirez.programming.kicks-ass.net>
References: <20180424004116.28151-1-subhra.mazumdar@oracle.com>
 <20180424004116.28151-3-subhra.mazumdar@oracle.com>
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On Mon, Apr 23, 2018 at 05:41:15PM -0700, subhra mazumdar wrote:
> @@ -17,6 +17,7 @@
>  #include <trace/events/sched.h>
>  
>  DEFINE_PER_CPU_SHARED_ALIGNED(struct rq, runqueues);
> +DEFINE_PER_CPU_SHARED_ALIGNED(int, next_cpu);
>  
>  #if defined(CONFIG_SCHED_DEBUG) && defined(HAVE_JUMP_LABEL)
>  /*
> @@ -6018,6 +6019,7 @@ void __init sched_init(void)
>  		struct rq *rq;
>  
>  		rq = cpu_rq(i);
> +		per_cpu(next_cpu, i) = -1;

If you leave it uninitialized it'll be 0, and we can avoid that extra
branch in the next patch, no?