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    Subject[PATCH] arm64: restore bogomips information in /proc/cpuinfo
    Date
    As what Pavel Machek reported [1], some userspace applications depend on
    bogomips showed by /proc/cpuinfo.

    Although there is much less legacy impact on aarch64 than arm, but it does
    break libvirt.

    Basically, this patch reverts commit 326b16db9f69fd0d279be873c6c00f88c0a4aad5
    ("arm64: delay: don't bother reporting bogomips in /proc/cpuinfo"), but with
    some tweak due to context change.

    [1] https://lkml.org/lkml/2015/1/4/132

    Signed-off-by: Yang Shi <yang.shi@linaro.org>
    ---
    arch/arm64/kernel/cpuinfo.c | 5 +++++
    arch/arm64/kernel/smp.c | 7 ++++++-
    2 files changed, 11 insertions(+), 1 deletion(-)

    diff --git a/arch/arm64/kernel/cpuinfo.c b/arch/arm64/kernel/cpuinfo.c
    index 706679d..8d4ba77 100644
    --- a/arch/arm64/kernel/cpuinfo.c
    +++ b/arch/arm64/kernel/cpuinfo.c
    @@ -30,6 +30,7 @@
    #include <linux/seq_file.h>
    #include <linux/sched.h>
    #include <linux/smp.h>
    +#include <linux/delay.h>

    /*
    * In case the boot CPU is hotpluggable, we record its initial state and
    @@ -112,6 +113,10 @@ static int c_show(struct seq_file *m, void *v)
    */
    seq_printf(m, "processor\t: %d\n", i);

    + seq_printf(m, "BogoMIPS\t: %lu.%02lu\n\n",
    + loops_per_jiffy / (500000UL/HZ),
    + loops_per_jiffy / (5000UL/HZ) % 100);
    +
    /*
    * Dump out the common processor features in a single line.
    * Userspace should read the hwcaps with getauxval(AT_HWCAP)
    diff --git a/arch/arm64/kernel/smp.c b/arch/arm64/kernel/smp.c
    index b1adc51..1bed772 100644
    --- a/arch/arm64/kernel/smp.c
    +++ b/arch/arm64/kernel/smp.c
    @@ -326,7 +326,12 @@ static void __init hyp_mode_check(void)

    void __init smp_cpus_done(unsigned int max_cpus)
    {
    - pr_info("SMP: Total of %d processors activated.\n", num_online_cpus());
    + unsigned long bogosum = loops_per_jiffy * num_online_cpus();
    +
    + pr_info("SMP: Total of %d processors activated (%lu.%02lu BogoMIPS).\n",
    + num_online_cpus(), bogosum / (500000/HZ),
    + (bogosum / (5000/HZ)) % 100);
    +
    setup_cpu_features();
    hyp_mode_check();
    apply_alternatives_all();
    --
    2.0.2


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