Add the ability to use random_table to randomize the order in which
pages are accessed. Add the -a argument to enable this new
behavior. This should make accesses less predictable and make for a
more realistic test. It includes the possibility that the same pages
may be hit multiple times during an iteration.
Signed-off-by: Colton Lewis <coltonlewis@xxxxxxxxxx>
---
.../testing/selftests/kvm/dirty_log_perf_test.c | 11 +++++++++--
.../selftests/kvm/include/perf_test_util.h | 2 ++
.../testing/selftests/kvm/lib/perf_test_util.c | 17 ++++++++++++++++-
3 files changed, 27 insertions(+), 3 deletions(-)
diff --git a/tools/testing/selftests/kvm/dirty_log_perf_test.c b/tools/testing/selftests/kvm/dirty_log_perf_test.c
index dcc5d44fc757..265cb4f7e088 100644
--- a/tools/testing/selftests/kvm/dirty_log_perf_test.c
+++ b/tools/testing/selftests/kvm/dirty_log_perf_test.c
@@ -132,6 +132,7 @@ struct test_params {
bool partition_vcpu_memory_access;
enum vm_mem_backing_src_type backing_src;
int slots;
+ bool random_access;
uint32_t random_seed;
};
@@ -227,6 +228,7 @@ static void run_test(enum vm_guest_mode mode, void *arg)
p->partition_vcpu_memory_access);
perf_test_set_wr_fract(vm, p->wr_fract);
+ perf_test_set_random_access(vm, p->random_access);
guest_num_pages = (nr_vcpus * guest_percpu_mem_size) >> vm->page_shift;
guest_num_pages = vm_adjust_num_guest_pages(mode, guest_num_pages);
@@ -357,10 +359,11 @@ static void run_test(enum vm_guest_mode mode, void *arg)
static void help(char *name)
{
puts("");
- printf("usage: %s [-h] [-i iterations] [-p offset] [-g] "
+ printf("usage: %s [-h] [-a] [-r random seed] [-i iterations] [-p offset] [-g] "
"[-m mode] [-n] [-b vcpu bytes] [-v vcpus] [-o] [-s mem type]"
"[-x memslots]\n", name);
puts("");
+ printf(" -a: access memory randomly rather than in order.\n");
printf(" -i: specify iteration counts (default: %"PRIu64")\n",
TEST_HOST_LOOP_N);
printf(" -g: Do not enable KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2. This\n"
@@ -403,6 +406,7 @@ int main(int argc, char *argv[])
.partition_vcpu_memory_access = true,
.backing_src = DEFAULT_VM_MEM_SRC,
.slots = 1,
+ .random_access = false,
.random_seed = time(NULL),
};
int opt;
@@ -414,8 +418,11 @@ int main(int argc, char *argv[])
guest_modes_append_default();
- while ((opt = getopt(argc, argv, "eghi:p:m:nb:f:v:or:s:x:")) != -1) {
+ while ((opt = getopt(argc, argv, "aeghi:p:m:nb:f:v:or:s:x:")) != -1) {
switch (opt) {
+ case 'a':
+ p.random_access = true;
+ break;
case 'e':
/* 'e' is for evil. */
run_vcpus_while_disabling_dirty_logging = true;
diff --git a/tools/testing/selftests/kvm/include/perf_test_util.h b/tools/testing/selftests/kvm/include/perf_test_util.h
index 597875d0c3db..6c6f81ce2216 100644
--- a/tools/testing/selftests/kvm/include/perf_test_util.h
+++ b/tools/testing/selftests/kvm/include/perf_test_util.h
@@ -39,6 +39,7 @@ struct perf_test_args {
/* Run vCPUs in L2 instead of L1, if the architecture supports it. */
bool nested;
+ bool random_access;
struct perf_test_vcpu_args vcpu_args[KVM_MAX_VCPUS];
};
@@ -56,6 +57,7 @@ struct kvm_vm *perf_test_create_vm(enum vm_guest_mode mode, int nr_vcpus,
void perf_test_destroy_vm(struct kvm_vm *vm);
void perf_test_set_wr_fract(struct kvm_vm *vm, int wr_fract);
+void perf_test_set_random_access(struct kvm_vm *vm, bool random_access);
void perf_test_start_vcpu_threads(int vcpus, void (*vcpu_fn)(struct perf_test_vcpu_args *));
void perf_test_join_vcpu_threads(int vcpus);
diff --git a/tools/testing/selftests/kvm/lib/perf_test_util.c b/tools/testing/selftests/kvm/lib/perf_test_util.c
index 3c7b93349fef..9838d1ad9166 100644
--- a/tools/testing/selftests/kvm/lib/perf_test_util.c
+++ b/tools/testing/selftests/kvm/lib/perf_test_util.c
@@ -52,6 +52,9 @@ void perf_test_guest_code(uint32_t vcpu_idx)
struct perf_test_vcpu_args *vcpu_args = &pta->vcpu_args[vcpu_idx];
uint64_t gva;
uint64_t pages;
+ uint64_t addr;
+ bool random_access = pta->random_access;
+ bool populated = false;
int i;
gva = vcpu_args->gva;
@@ -62,7 +65,11 @@ void perf_test_guest_code(uint32_t vcpu_idx)
while (true) {
for (i = 0; i < pages; i++) {
- uint64_t addr = gva + (i * pta->guest_page_size);
+ if (populated && random_access)
+ addr = gva +
+ ((random_table[vcpu_idx][i] % pages) * pta->guest_page_size);
+ else
+ addr = gva + (i * pta->guest_page_size);
if (random_table[vcpu_idx][i] % 100 < pta->wr_fract)
*(uint64_t *)addr = 0x0123456789ABCDEF;
@@ -70,6 +77,7 @@ void perf_test_guest_code(uint32_t vcpu_idx)
READ_ONCE(*(uint64_t *)addr);
}
+ populated = true;
GUEST_SYNC(1);
}
}
@@ -169,6 +177,7 @@ struct kvm_vm *perf_test_create_vm(enum vm_guest_mode mode, int nr_vcpus,
/* By default vCPUs will write to memory. */
pta->wr_fract = 100;
+ pta->random_access = false;
/*
* Snapshot the non-huge page size. This is used by the guest code to
@@ -276,6 +285,12 @@ void perf_test_set_wr_fract(struct kvm_vm *vm, int wr_fract)
sync_global_to_guest(vm, perf_test_args);
}
+void perf_test_set_random_access(struct kvm_vm *vm, bool random_access)
+{
+ perf_test_args.random_access = random_access;
+ sync_global_to_guest(vm, perf_test_args);
+}
+
uint64_t __weak perf_test_nested_pages(int nr_vcpus)
{
return 0;
--
2.37.1.559.g78731f0fdb-goog
