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    SubjectRe: [PATCH] refperf: work around 64-bit division
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    On 5/29/20 1:15 PM, Arnd Bergmann wrote:
    > A 64-bit division was introduced in refperf, breaking compilation
    > on all 32-bit architectures:
    >
    > kernel/rcu/refperf.o: in function `main_func':
    > refperf.c:(.text+0x57c): undefined reference to `__aeabi_uldivmod'
    >
    > Work it by using div_u64 to mark the expensive operation.
    >
    > Fixes: bd5b16d6c88d ("refperf: Allow decimal nanoseconds")
    > Signed-off-by: Arnd Bergmann <arnd@arndb.de>

    Acked-by: Randy Dunlap <rdunlap@infradead.org> # build-tested

    Thanks.

    > ---
    > kernel/rcu/refperf.c | 9 +++++++--
    > 1 file changed, 7 insertions(+), 2 deletions(-)
    >
    > diff --git a/kernel/rcu/refperf.c b/kernel/rcu/refperf.c
    > index 47df72c492b3..c2366648981d 100644
    > --- a/kernel/rcu/refperf.c
    > +++ b/kernel/rcu/refperf.c
    > @@ -386,7 +386,7 @@ static int main_func(void *arg)
    > if (torture_must_stop())
    > goto end;
    >
    > - result_avg[exp] = 1000 * process_durations(nreaders) / (nreaders * loops);
    > + result_avg[exp] = div_u64(1000 * process_durations(nreaders), nreaders * loops);
    > }
    >
    > // Print the average of all experiments
    > @@ -397,9 +397,14 @@ static int main_func(void *arg)
    > strcat(buf, "Threads\tTime(ns)\n");
    >
    > for (exp = 0; exp < nruns; exp++) {
    > + u64 avg;
    > + u32 rem;
    > +
    > if (errexit)
    > break;
    > - sprintf(buf1, "%d\t%llu.%03d\n", exp + 1, result_avg[exp] / 1000, (int)(result_avg[exp] % 1000));
    > +
    > + avg = div_s64_rem(result_avg[exp], 1000, &rem);
    > + sprintf(buf1, "%d\t%llu.%03d\n", exp + 1, avg, rem);
    > strcat(buf, buf1);
    > }
    >
    >


    --
    ~Randy

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