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| author |   Arnd Bergmann <arnd@arndb.de> | 2020-05-29 14:36:26 -0700 |
|---|---|---|
| committer |   Paul E. McKenney <paulmck@kernel.org> | 2020-06-29 12:00:45 -0700 |
| commit | 7c944d7c67daee84e3c756bb74ad2f32b28c41cf (patch) | |
| tree | d41f48b6d2150158de7bc32fe40e4a1cbd3ddd4b /kernel/rcu | |
| parent | doc: Document rcuperf's module parameters (diff) | |
| download | linux-dev-7c944d7c67daee84e3c756bb74ad2f32b28c41cf.tar.xz linux-dev-7c944d7c67daee84e3c756bb74ad2f32b28c41cf.zip | |
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/rcu')
| -rw-r--r-- | kernel/rcu/refperf.c | 8 |
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); } |