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Date:   Thu, 7 Mar 2019 15:33:44 +0100
From:   Sebastian Andrzej Siewior <bigeasy@linutronix.de>
To:     Yongxin Liu <yongxin.liu@windriver.com>
Cc:     linux-kernel@vger.kernel.org, linux-rt-users@vger.kernel.org,
        tglx@linutronix.de, rostedt@goodmis.org, dan.j.williams@intel.com,
        pagupta@redhat.com, paul.gortmaker@windriver.com,
        linux-nvdimm@lists.01.org
Subject: Re: [PATCH RT] nvdimm: make lane acquirement RT aware
Message-ID: <20190307143344.ytsnbmot5tjzjhip@linutronix.de>
References: <20190306095709.23138-1-yongxin.liu@windriver.com>
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On 2019-03-06 17:57:09 [+0800], Yongxin Liu wrote:
> In this change, we replace get_cpu/put_cpu with local_lock_cpu/
> local_unlock_cpu, and introduce per CPU variable "ndl_local_lock".
> Due to preemption on RT, this lock can avoid race condition for the
> same lane on the same CPU. When CPU number is greater than the lane
> number, lane can be shared among CPUs. "ndl_lock->lock" is used to
> protect the lane in this situation.

so what was the reason that get_cpu() can't be replaced with
raw_smp_processor_id()?

Sebastian