linux-kernel - sched: current instead rq->current

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Message-ID: <1471289435.8946.28.camel@cvidal.org>
Date:	Mon, 15 Aug 2016 21:30:35 +0200
From:	Colin Vidal <colin@...dal.org>
To:	linux-kernel@...r.kernel.org
Subject: sched: current instead rq->current

Hello,

At the beginning of __schedule (kernel/sched/core.c), the current task
is get with rq->curr. I try to to understand why not directly using
current instead?

Since a runqueue is specific to a CPU, it dosen't make sense to get the
the current task of another CPU's runqueue. Yes?

I try the following of Linus's master branch

-       int cpu;

-       cpu = smp_processor_id();
-       rq = cpu_rq(cpu);
-       prev = rq->curr;
+       rq = cpu_rq(smp_processor_id());
+       prev = current;

and it seems to work (only tested on x86-64), but... To simple?

Thanks!

Colin