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authorArnd Bergmann <arnd@arndb.de>2020-05-29 14:36:26 -0700
committerPaul E. McKenney <paulmck@kernel.org>2020-06-29 12:00:45 -0700
commit7c944d7c67daee84e3c756bb74ad2f32b28c41cf (patch)
treed41f48b6d2150158de7bc32fe40e4a1cbd3ddd4b /kernel
parent847dd70aa971a67b4dfdb8f131428dfb90d88714 (diff)
refperf: Work around 64-bit division
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' Fix this by using div_u64 to mark the expensive operation. [ paulmck: Update primitive and format per Nathan Chancellor. ] Fixes: bd5b16d6c88d ("refperf: Allow decimal nanoseconds") Reported-by: kbuild test robot <lkp@intel.com> Reported-by: Valdis Klētnieks <valdis.kletnieks@vt.edu> Acked-by: Randy Dunlap <rdunlap@infradead.org> # build-tested Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Diffstat (limited to 'kernel')
-rw-r--r--kernel/rcu/refperf.c8
1 files changed, 6 insertions, 2 deletions
diff --git a/kernel/rcu/refperf.c b/kernel/rcu/refperf.c
index 063eeb0473a1..80d449060bdf 100644
--- a/kernel/rcu/refperf.c
+++ b/kernel/rcu/refperf.c
@@ -478,7 +478,7 @@ 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
@@ -489,9 +489,13 @@ static int main_func(void *arg)
strcat(buf, "Runs\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_u64_rem(result_avg[exp], 1000, &rem);
+ sprintf(buf1, "%d\t%llu.%03u\n", exp + 1, avg, rem);
strcat(buf, buf1);
}