Re: [RFC/PATCH] arm: do not skip SMP init calls on SMP_ON_UP case

From	Nikita Yushchenko <nyushchenko@dev.rtsoft.ru>
Newsgroups	linux.kernel
Subject	Re: [RFC/PATCH] arm: do not skip SMP init calls on SMP_ON_UP case
Date	2015-11-24 16:10 +0100
Message-ID	<qynod-1lP-15@gated-at.bofh.it> (permalink)
References	(3 earlier) <qxYzw-1JL-9@gated-at.bofh.it> <qxYJc-1N0-7@gated-at.bofh.it> <qxYJc-1N0-9@gated-at.bofh.it> <qxZ2y-29g-13@gated-at.bofh.it> <qynez-130-33@gated-at.bofh.it>
Organization	RTSoft Software Development Center

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> I'm still trying to understand what is going on, and my printk()s show
> that this is not entirely true.
> 
> When smp_init() is entered on mainline om imx6s, cpu_possible_mask and
> cpu_present_mask both contain two cpus. These get initialized in
> arm_dt_init_cpu_maps() and stay unmodified since then.
> 
> But cpu_online() returns 1 for cpu0 and 0 from cpu1 - thus it is
> cpu_online() check, not possible_mask or present_mask, that prevents
> cpu1 initialization attempt.

Sorry was too quick to type.

cpu_online(0) is true and cpu_online(1) is false.
It is natural, since cpu0 is already running.
Thus cpu_up(1) is entered!

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Thread

[RFC/PATCH] arm: do not skip SMP init calls on SMP_ON_UP case nyushchenko@dev.rtsoft.ru - 2015-11-23 13:00 +0100
  Re: [RFC/PATCH] arm: do not skip SMP init calls on SMP_ON_UP case Nikita Yushchenko <nyushchenko@dev.rtsoft.ru> - 2015-11-23 13:10 +0100
    Re: [RFC/PATCH] arm: do not skip SMP init calls on SMP_ON_UP case Russell King - ARM Linux <linux@arm.linux.org.uk> - 2015-11-23 13:20 +0100
      Re: [RFC/PATCH] arm: do not skip SMP init calls on SMP_ON_UP case Nikita Yushchenko <nyushchenko@dev.rtsoft.ru> - 2015-11-23 13:50 +0100
    Re: [RFC/PATCH] arm: do not skip SMP init calls on SMP_ON_UP case Russell King - ARM Linux <linux@arm.linux.org.uk> - 2015-11-23 13:20 +0100
    Re: [RFC/PATCH] arm: do not skip SMP init calls on SMP_ON_UP case Vladimir Murzin <vladimir.murzin@arm.com> - 2015-11-23 13:40 +0100
      Re: [RFC/PATCH] arm: do not skip SMP init calls on SMP_ON_UP case Nikita Yushchenko <nyushchenko@dev.rtsoft.ru> - 2015-11-23 13:50 +0100
        Re: [RFC/PATCH] arm: do not skip SMP init calls on SMP_ON_UP case Russell King - ARM Linux <linux@arm.linux.org.uk> - 2015-11-23 14:10 +0100
          Re: [RFC/PATCH] arm: do not skip SMP init calls on SMP_ON_UP case Nikita Yushchenko <nyushchenko@dev.rtsoft.ru> - 2015-11-24 16:00 +0100
            Re: [RFC/PATCH] arm: do not skip SMP init calls on SMP_ON_UP case Nikita Yushchenko <nyushchenko@dev.rtsoft.ru> - 2015-11-24 16:10 +0100
              Re: [RFC/PATCH] arm: do not skip SMP init calls on SMP_ON_UP case Nikita Yushchenko <nyushchenko@dev.rtsoft.ru> - 2015-11-24 16:30 +0100
            Re: [RFC/PATCH] arm: do not skip SMP init calls on SMP_ON_UP case Russell King - ARM Linux <linux@arm.linux.org.uk> - 2015-11-24 16:40 +0100
              Re: [RFC/PATCH] arm: do not skip SMP init calls on SMP_ON_UP case Nikita Yushchenko <nyushchenko@dev.rtsoft.ru> - 2015-11-28 12:20 +0100
                Re: [RFC/PATCH] arm: do not skip SMP init calls on SMP_ON_UP case Nikita Yushchenko <nyushchenko@dev.rtsoft.ru> - 2015-11-30 09:30 +0100
      Re: [RFC/PATCH] arm: do not skip SMP init calls on SMP_ON_UP case Nikita Yushchenko <nyushchenko@dev.rtsoft.ru> - 2015-11-23 13:50 +0100
  Re: [RFC/PATCH] arm: do not skip SMP init calls on SMP_ON_UP case Russell King - ARM Linux <linux@arm.linux.org.uk> - 2015-11-23 13:10 +0100

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