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Date: Wed, 9 Sep 2015 10:29:45 +0800
From: Baoquan He <bhe@redhat.com>
To: Sedat Dilek <sedat.dilek@gmail.com>
Cc: Tejun Heo <tj@kernel.org>, Christoph Lameter <cl@linux.com>,
        LKML <linux-kernel@vger.kernel.org>,
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        Thomas Gleixner <tglx@linutronix.de>, Thomas Graf <tgraf@suug.ch>,
        Ingo Molnar <mingo@kernel.org>,
        the arch/x86 maintainers <x86@kernel.org>
Subject: Re: [llvmlinux] percpu | bitmap issue? (Cannot boot on bare metal
 due to a kernel NULL pointer dereference)
Message-ID: <20150909022945.GB1998@dhcp-17-102.nay.redhat.com>
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Seems it happened when call num_possible_cpus() which is a inline
function to call __bitmap_weight(). So did you check
lib/bitmap.c:__bitmap_weight() by objdump?

setup_percpu: NR_CPUS:256 nr_cpumask_bits:256 nr_cpu_ids:1 nr_node_ids:1

Thanks
Baoquan