Commit 7c944d7c authored by Arnd Bergmann's avatar Arnd Bergmann Committed by Paul E. McKenney
Browse files

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: default avatarkbuild test robot <lkp@intel.com>
Reported-by: default avatarValdis Klētnieks <valdis.kletnieks@vt.edu>
Acked-by: Randy Dunlap <rdunlap@infradead.org> # build-tested
Signed-off-by: default avatarArnd Bergmann <arnd@arndb.de>
Signed-off-by: default avatarPaul E. McKenney <paulmck@kernel.org>
parent 847dd70a

kernel/rcu/refperf.c

+6 −2
Original line number Diff line number Diff line
@@ -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);

	}