Messages in this thread Patch in this message | | | From | paulmck@kernel ... | Subject | [PATCH tip/core/rcu 23/30] refperf: Work around 64-bit division | Date | Mon, 22 Jun 2020 17:30:06 -0700 |
| |
From: Arnd Bergmann <arnd@arndb.de>
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> --- kernel/rcu/refperf.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-)
diff --git a/kernel/rcu/refperf.c b/kernel/rcu/refperf.c index 063eeb0..80d4490 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); } -- 2.9.5
| |