diff options
Diffstat (limited to 'tools/testing/selftests/kvm/dirty_log_perf_test.c')
| -rw-r--r-- | tools/testing/selftests/kvm/dirty_log_perf_test.c | 37 |
1 files changed, 25 insertions, 12 deletions
diff --git a/tools/testing/selftests/kvm/dirty_log_perf_test.c b/tools/testing/selftests/kvm/dirty_log_perf_test.c index eb63ca12b519..e9ce50fe7295 100644 --- a/tools/testing/selftests/kvm/dirty_log_perf_test.c +++ b/tools/testing/selftests/kvm/dirty_log_perf_test.c @@ -128,10 +128,10 @@ static void vcpu_worker(struct perf_test_vcpu_args *vcpu_args) struct test_params { unsigned long iterations; uint64_t phys_offset; - int wr_fract; bool partition_vcpu_memory_access; enum vm_mem_backing_src_type backing_src; int slots; + uint32_t write_percent; uint32_t random_seed; }; @@ -228,7 +228,7 @@ static void run_test(enum vm_guest_mode mode, void *arg) pr_info("Random seed: %u\n", p->random_seed); perf_test_set_random_seed(vm, p->random_seed); - perf_test_set_wr_fract(vm, p->wr_fract); + perf_test_set_write_percent(vm, p->write_percent); guest_num_pages = (nr_vcpus * guest_percpu_mem_size) >> vm->page_shift; guest_num_pages = vm_adjust_num_guest_pages(mode, guest_num_pages); @@ -251,6 +251,14 @@ static void run_test(enum vm_guest_mode mode, void *arg) for (i = 0; i < nr_vcpus; i++) vcpu_last_completed_iteration[i] = -1; + /* + * Use 100% writes during the population phase 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. + */ + perf_test_set_write_percent(vm, 100); perf_test_start_vcpu_threads(nr_vcpus, vcpu_worker); /* Allow the vCPUs to populate memory */ @@ -272,6 +280,8 @@ static void run_test(enum vm_guest_mode mode, void *arg) pr_info("Enabling dirty logging time: %ld.%.9lds\n\n", ts_diff.tv_sec, ts_diff.tv_nsec); + perf_test_set_write_percent(vm, p->write_percent); + while (iteration < p->iterations) { /* * Incrementing the iteration number will start the vCPUs @@ -356,7 +366,7 @@ static void help(char *name) puts(""); printf("usage: %s [-h] [-i iterations] [-p offset] [-g] " "[-m mode] [-n] [-b vcpu bytes] [-v vcpus] [-o] [-r random seed ] [-s mem type]" - "[-x memslots] [-c physical cpus to run test on]\n", name); + "[-x memslots] [-w percentage] [-c physical cpus to run test on]\n", name); puts(""); printf(" -i: specify iteration counts (default: %"PRIu64")\n", TEST_HOST_LOOP_N); @@ -376,10 +386,6 @@ static void help(char *name) printf(" -b: specify the size of the memory region which should be\n" " dirtied by each vCPU. e.g. 10M or 3G.\n" " (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"); 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"); @@ -387,6 +393,11 @@ static void help(char *name) backing_src_help("-s"); printf(" -x: Split the memory region into this number of memslots.\n" " (default: 1)\n"); + printf(" -w: specify the percentage of pages which should be written to\n" + " as an integer from 0-100 inclusive. This is probabalistic,\n" + " so -w X means each page has an X%% chance of writing\n" + " and a (100-X)%% chance of reading.\n" + " (default: 100 i.e. all pages are written to.)\n"); printf(" -c: Pin tasks to physical CPUs. Takes a list of comma separated\n" " values (target pCPU), one for each vCPU, plus an optional\n" " entry for the main application task (specified via entry\n" @@ -408,11 +419,11 @@ int main(int argc, char *argv[]) const char *pcpu_list = NULL; struct test_params p = { .iterations = TEST_HOST_LOOP_N, - .wr_fract = 1, .partition_vcpu_memory_access = true, .backing_src = DEFAULT_VM_MEM_SRC, .slots = 1, .random_seed = 1, + .write_percent = 100, }; int opt; @@ -423,7 +434,7 @@ int main(int argc, char *argv[]) guest_modes_append_default(); - while ((opt = getopt(argc, argv, "b:c:ef:ghi:m:nop:r:s:v:x:")) != -1) { + while ((opt = getopt(argc, argv, "b:c:eghi:m:nop:r:s:v:x:w:")) != -1) { switch (opt) { case 'b': guest_percpu_mem_size = parse_size(optarg); @@ -435,9 +446,6 @@ int main(int argc, char *argv[]) /* 'e' is for evil. */ run_vcpus_while_disabling_dirty_logging = true; break; - case 'f': - p.wr_fract = atoi_positive("Write fraction", optarg); - break; case 'g': dirty_log_manual_caps = 0; break; @@ -470,6 +478,11 @@ int main(int argc, char *argv[]) TEST_ASSERT(nr_vcpus <= max_vcpus, "Invalid number of vcpus, must be between 1 and %d", max_vcpus); break; + case 'w': + p.write_percent = atoi_non_negative("Write percentage", optarg); + TEST_ASSERT(p.write_percent <= 100, + "Write percentage must be between 0 and 100"); + break; case 'x': p.slots = atoi_positive("Number of slots", optarg); break; |