[kernel][test] Microbenchmarks for brwlock
Adds microbenchmarks for uncontended reader and writer acquisition, similar to that of
the mutex microbenchmark.
ZX-3085 #comment
Test: k ut bench
Change-Id: Id6a78d217b3d437e8c2008ef9ba53434754485b4
diff --git a/kernel/tests/benchmarks.cpp b/kernel/tests/benchmarks.cpp
index 67a3062..8b86056 100644
--- a/kernel/tests/benchmarks.cpp
+++ b/kernel/tests/benchmarks.cpp
@@ -10,6 +10,7 @@
#include <arch/ops.h>
#include <err.h>
#include <inttypes.h>
+#include <kernel/brwlock.h>
#include <kernel/mp.h>
#include <kernel/mutex.h>
#include <kernel/spinlock.h>
@@ -270,6 +271,28 @@
printf("%" PRIu64 " cycles to acquire/release uncontended mutex %u times (%" PRIu64 " cycles per)\n", c, count, c / count);
}
+__NO_INLINE static void bench_rwlock() {
+ BrwLock rw;
+ static const uint count = 128 * 1024 * 1024;
+ uint64_t c = arch_cycle_count();
+ for (size_t i = 0; i < count; i++) {
+ rw.ReadAcquire();
+ rw.ReadRelease();
+ }
+ c = arch_cycle_count() - c;
+
+ printf("%" PRIu64 " cycles to acquire/release uncontended brwlock for read %u times (%" PRIu64 " cycles per)\n", c, count, c / count);
+
+ c = arch_cycle_count();
+ for (size_t i = 0; i < count; i++) {
+ rw.WriteAcquire();
+ rw.WriteRelease();
+ }
+ c = arch_cycle_count() - c;
+
+ printf("%" PRIu64 " cycles to acquire/release uncontended brwlock for write %u times (%" PRIu64 " cycles per)\n", c, count, c / count);
+}
+
int benchmarks(int, const cmd_args*, uint32_t) {
bench_set_overhead();
bench_memcpy();
@@ -286,6 +309,7 @@
bench_spinlock();
bench_mutex();
+ bench_rwlock();
return 0;
}
