diff options
| author | Colton Lewis <coltonlewis@google.com> | 2022-11-07 18:22:07 +0000 |
|---|---|---|
| committer | Sean Christopherson <seanjc@google.com> | 2022-11-16 10:57:19 -0800 |
| commit | 6864c6442f4dfa02c7cf48199cf3ea6bb1fe74ed (patch) | |
| tree | 53f27995f75db67791895886364121aa6480740f /tools/testing/selftests/kvm/include/perf_test_util.h | |
| parent | f11aa24bdbc66a10378d28ee962b95426e8d2a09 (diff) | |
KVM: selftests: randomize which pages are written vs read
Randomize which pages are written vs read using the random number
generator.
Change the variable wr_fract and associated function calls to
write_percent that now operates as a percentage from 0 to 100 where X
means each page has an X% chance of being written. Change the -f
argument to -w to reflect the new variable semantics. Keep the same
default of 100% writes.
Population always uses 100% writes to ensure all memory is actually
populated and not just mapped to the zero page. The prevents expensive
copy-on-write faults from occurring during the dirty memory iterations
below, which would pollute the performance results.
Each vCPU calculates its own random seed by adding its index to the
seed provided.
Signed-off-by: Colton Lewis <coltonlewis@google.com>
Reviewed-by: David Matlack <dmatlack@google.com>
Link: https://lore.kernel.org/r/20221107182208.479157-4-coltonlewis@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Diffstat (limited to 'tools/testing/selftests/kvm/include/perf_test_util.h')
| -rw-r--r-- | tools/testing/selftests/kvm/include/perf_test_util.h | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/tools/testing/selftests/kvm/include/perf_test_util.h b/tools/testing/selftests/kvm/include/perf_test_util.h index 5a0e48b625a2..6470ca0fec4c 100644 --- a/tools/testing/selftests/kvm/include/perf_test_util.h +++ b/tools/testing/selftests/kvm/include/perf_test_util.h @@ -36,7 +36,7 @@ struct perf_test_args { uint64_t size; uint64_t guest_page_size; uint32_t random_seed; - int wr_fract; + uint32_t write_percent; /* Run vCPUs in L2 instead of L1, if the architecture supports it. */ bool nested; @@ -56,7 +56,7 @@ struct kvm_vm *perf_test_create_vm(enum vm_guest_mode mode, int nr_vcpus, bool partition_vcpu_memory_access); 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_write_percent(struct kvm_vm *vm, uint32_t write_percent); void perf_test_set_random_seed(struct kvm_vm *vm, uint32_t random_seed); void perf_test_start_vcpu_threads(int vcpus, void (*vcpu_fn)(struct perf_test_vcpu_args *)); |