Randomize which pages are written vs read by using the random number
table for each page modulo 100. This changes how the -w argument
works. It is now a percentage from 0 to 100 inclusive that represents
what percentage of accesses are writes. It keeps the same default of
100 percent writes.
Signed-off-by: Colton Lewis <coltonlewis@xxxxxxxxxx>
---
tools/testing/selftests/kvm/dirty_log_perf_test.c | 12 +++++++-----
tools/testing/selftests/kvm/lib/perf_test_util.c | 4 ++--
2 files changed, 9 insertions(+), 7 deletions(-)
diff --git a/tools/testing/selftests/kvm/dirty_log_perf_test.c b/tools/testing/selftests/kvm/dirty_log_perf_test.c
index 80a1cbe7fbb0..dcc5d44fc757 100644
--- a/tools/testing/selftests/kvm/dirty_log_perf_test.c
+++ b/tools/testing/selftests/kvm/dirty_log_perf_test.c
@@ -381,8 +381,8 @@ static void help(char *name)
" (default: 1G)\n");
printf(" -f: specify the fraction of pages which should be written to\n"
" as opposed to simply read, in the form\n"
- " 1/<fraction of pages to write>.\n"
- " (default: 1 i.e. all pages are written to.)\n");
+ " [0-100]%% of pages to write.\n"
+ " (default: 100 i.e. all pages are written to.)\n");
printf(" -v: specify the number of vCPUs to run.\n");
printf(" -o: Overlap guest memory accesses instead of partitioning\n"
" them into a separate region of memory for each vCPU.\n");
@@ -399,7 +399,7 @@ int main(int argc, char *argv[])
int max_vcpus = kvm_check_cap(KVM_CAP_MAX_VCPUS);
struct test_params p = {
.iterations = TEST_HOST_LOOP_N,
- .wr_fract = 1,
+ .wr_fract = 100,
.partition_vcpu_memory_access = true,
.backing_src = DEFAULT_VM_MEM_SRC,
.slots = 1,
@@ -439,8 +439,10 @@ int main(int argc, char *argv[])
break;
case 'f':
p.wr_fract = atoi(optarg);
- TEST_ASSERT(p.wr_fract >= 1,
- "Write fraction cannot be less than one");
+ TEST_ASSERT(p.wr_fract >= 0,
+ "Write fraction cannot be less than 0");
+ TEST_ASSERT(p.wr_fract <= 100,
+ "Write fraction cannot be greater than 100");
break;
case 'v':
nr_vcpus = atoi(optarg);
diff --git a/tools/testing/selftests/kvm/lib/perf_test_util.c b/tools/testing/selftests/kvm/lib/perf_test_util.c
index b04e8d2c0f37..3c7b93349fef 100644
--- a/tools/testing/selftests/kvm/lib/perf_test_util.c
+++ b/tools/testing/selftests/kvm/lib/perf_test_util.c
@@ -64,7 +64,7 @@ void perf_test_guest_code(uint32_t vcpu_idx)
for (i = 0; i < pages; i++) {
uint64_t addr = gva + (i * pta->guest_page_size);
- if (i % pta->wr_fract == 0)
+ if (random_table[vcpu_idx][i] % 100 < pta->wr_fract)
*(uint64_t *)addr = 0x0123456789ABCDEF;
else
READ_ONCE(*(uint64_t *)addr);
@@ -168,7 +168,7 @@ struct kvm_vm *perf_test_create_vm(enum vm_guest_mode mode, int nr_vcpus,
pr_info("Testing guest mode: %s\n", vm_guest_mode_string(mode));
/* By default vCPUs will write to memory. */
- pta->wr_fract = 1;
+ pta->wr_fract = 100;
/*
* Snapshot the non-huge page size. This is used by the guest code to
--
2.37.1.559.g78731f0fdb-goog
