| Message ID | 20220909124300.3409187-3-coltonlewis@google.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | KVM: selftests: randomize memory access of dirty_log_perf_test | expand |
On Fri, Sep 09, 2022 at 12:42:59PM +0000, Colton Lewis wrote: > 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. > Reviewed-by: Ricardo Koller <ricarkol@google.com> > Signed-off-by: Colton Lewis <coltonlewis@google.com> > --- > .../selftests/kvm/access_tracking_perf_test.c | 2 +- > .../selftests/kvm/dirty_log_perf_test.c | 30 +++++++++++-------- > .../selftests/kvm/include/perf_test_util.h | 4 +-- > .../selftests/kvm/lib/perf_test_util.c | 10 +++---- > 4 files changed, 25 insertions(+), 21 deletions(-) > > diff --git a/tools/testing/selftests/kvm/access_tracking_perf_test.c b/tools/testing/selftests/kvm/access_tracking_perf_test.c > index d8909032317a..d86046ef3a0b 100644 > --- a/tools/testing/selftests/kvm/access_tracking_perf_test.c > +++ b/tools/testing/selftests/kvm/access_tracking_perf_test.c > @@ -274,7 +274,7 @@ static void run_iteration(struct kvm_vm *vm, int vcpus, const char *description) > static void access_memory(struct kvm_vm *vm, int vcpus, enum access_type access, > const char *description) > { > - perf_test_set_wr_fract(vm, (access == ACCESS_READ) ? INT_MAX : 1); > + perf_test_set_write_percent(vm, (access == ACCESS_READ) ? 0 : 100); > iteration_work = ITERATION_ACCESS_MEMORY; > run_iteration(vm, vcpus, description); > } > diff --git a/tools/testing/selftests/kvm/dirty_log_perf_test.c b/tools/testing/selftests/kvm/dirty_log_perf_test.c > index 2f91acd94130..c2ad299b3760 100644 > --- a/tools/testing/selftests/kvm/dirty_log_perf_test.c > +++ b/tools/testing/selftests/kvm/dirty_log_perf_test.c > @@ -122,10 +122,10 @@ 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; > }; > > @@ -223,7 +223,6 @@ 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); > > guest_num_pages = (nr_vcpus * guest_percpu_mem_size) >> vm_get_page_shift(vm); > guest_num_pages = vm_adjust_num_guest_pages(mode, guest_num_pages); > @@ -248,6 +247,7 @@ static void run_test(enum vm_guest_mode mode, void *arg) > for (vcpu_id = 0; vcpu_id < nr_vcpus; vcpu_id++) > vcpu_last_completed_iteration[vcpu_id] = -1; > > + perf_test_set_write_percent(vm, 100); > perf_test_start_vcpu_threads(nr_vcpus, vcpu_worker); > > /* Allow the vCPUs to populate memory */ > @@ -269,6 +269,8 @@ 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 > @@ -341,7 +343,7 @@ 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]\n", name); > + "[-x memslots] [-w percentage]\n", name); > puts(""); > printf(" -i: specify iteration counts (default: %"PRIu64")\n", > TEST_HOST_LOOP_N); > @@ -358,10 +360,6 @@ 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"); > @@ -369,6 +367,11 @@ 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"); > puts(""); > exit(0); > } > @@ -378,10 +381,10 @@ 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, > .partition_vcpu_memory_access = true, > .backing_src = DEFAULT_VM_MEM_SRC, > .slots = 1, > + .write_percent = 100, > .random_seed = time(NULL), > }; > int opt; > @@ -393,7 +396,7 @@ int main(int argc, char *argv[]) > > guest_modes_append_default(); > > - while ((opt = getopt(argc, argv, "ghi:p:m:nb:f:v:or:s:x:")) != -1) { > + while ((opt = getopt(argc, argv, "ghi:p:m:nb:v:or:s:x:w:")) != -1) { > switch (opt) { > case 'g': > dirty_log_manual_caps = 0; > @@ -413,10 +416,11 @@ int main(int argc, char *argv[]) > case 'b': > guest_percpu_mem_size = parse_size(optarg); > break; > - case 'f': > - p.wr_fract = atoi(optarg); > - TEST_ASSERT(p.wr_fract >= 1, > - "Write fraction cannot be less than one"); > + case 'w': > + p.write_percent = atoi(optarg); > + TEST_ASSERT(p.write_percent >= 0 > + && p.write_percent <= 100, > + "Write percentage must be between 0 and 100"); > break; > case 'v': > nr_vcpus = atoi(optarg); > diff --git a/tools/testing/selftests/kvm/include/perf_test_util.h b/tools/testing/selftests/kvm/include/perf_test_util.h > index f18530984b42..f93f2ea7c6a3 100644 > --- a/tools/testing/selftests/kvm/include/perf_test_util.h > +++ b/tools/testing/selftests/kvm/include/perf_test_util.h > @@ -35,7 +35,7 @@ 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; > @@ -51,7 +51,7 @@ struct kvm_vm *perf_test_create_vm(enum vm_guest_mode mode, int 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 *)); > diff --git a/tools/testing/selftests/kvm/lib/perf_test_util.c b/tools/testing/selftests/kvm/lib/perf_test_util.c > index 4d9c7d7693d9..12a3597be1f9 100644 > --- a/tools/testing/selftests/kvm/lib/perf_test_util.c > +++ b/tools/testing/selftests/kvm/lib/perf_test_util.c > @@ -60,7 +60,7 @@ void perf_test_guest_code(uint32_t vcpu_id) > uint64_t addr = gva + (i * pta->guest_page_size); > guest_random(&rand); > > - if (i % pta->wr_fract == 0) > + if (rand % 100 < pta->write_percent) > *(uint64_t *)addr = 0x0123456789ABCDEF; > else > READ_ONCE(*(uint64_t *)addr); > @@ -118,7 +118,7 @@ struct kvm_vm *perf_test_create_vm(enum vm_guest_mode mode, int vcpus, > pr_info("Testing guest mode: %s\n", vm_guest_mode_string(mode)); > > /* Set perf_test_args defaults. */ > - pta->wr_fract = 1; > + pta->write_percent = 100; > pta->random_seed = time(NULL); > > /* > @@ -221,10 +221,10 @@ void perf_test_destroy_vm(struct kvm_vm *vm) > kvm_vm_free(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) > { > - perf_test_args.wr_fract = wr_fract; > - sync_global_to_guest(vm, perf_test_args); > + perf_test_args.write_percent = write_percent; > + sync_global_to_guest(vm, perf_test_args.write_percent); > } > > void perf_test_set_random_seed(struct kvm_vm *vm, uint32_t random_seed) > -- > 2.37.2.789.g6183377224-goog >
On Fri, Sep 09, 2022 at 12:42:59PM +0000, Colton Lewis wrote: > 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. > > Signed-off-by: Colton Lewis <coltonlewis@google.com> > --- > .../selftests/kvm/access_tracking_perf_test.c | 2 +- > .../selftests/kvm/dirty_log_perf_test.c | 30 +++++++++++-------- > .../selftests/kvm/include/perf_test_util.h | 4 +-- > .../selftests/kvm/lib/perf_test_util.c | 10 +++---- > 4 files changed, 25 insertions(+), 21 deletions(-) > > diff --git a/tools/testing/selftests/kvm/access_tracking_perf_test.c b/tools/testing/selftests/kvm/access_tracking_perf_test.c > index d8909032317a..d86046ef3a0b 100644 > --- a/tools/testing/selftests/kvm/access_tracking_perf_test.c > +++ b/tools/testing/selftests/kvm/access_tracking_perf_test.c > @@ -274,7 +274,7 @@ static void run_iteration(struct kvm_vm *vm, int vcpus, const char *description) > static void access_memory(struct kvm_vm *vm, int vcpus, enum access_type access, > const char *description) > { > - perf_test_set_wr_fract(vm, (access == ACCESS_READ) ? INT_MAX : 1); > + perf_test_set_write_percent(vm, (access == ACCESS_READ) ? 0 : 100); > iteration_work = ITERATION_ACCESS_MEMORY; > run_iteration(vm, vcpus, description); > } > diff --git a/tools/testing/selftests/kvm/dirty_log_perf_test.c b/tools/testing/selftests/kvm/dirty_log_perf_test.c > index 2f91acd94130..c2ad299b3760 100644 > --- a/tools/testing/selftests/kvm/dirty_log_perf_test.c > +++ b/tools/testing/selftests/kvm/dirty_log_perf_test.c > @@ -122,10 +122,10 @@ 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; > }; > > @@ -223,7 +223,6 @@ 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); > > guest_num_pages = (nr_vcpus * guest_percpu_mem_size) >> vm_get_page_shift(vm); > guest_num_pages = vm_adjust_num_guest_pages(mode, guest_num_pages); > @@ -248,6 +247,7 @@ static void run_test(enum vm_guest_mode mode, void *arg) > for (vcpu_id = 0; vcpu_id < nr_vcpus; vcpu_id++) > vcpu_last_completed_iteration[vcpu_id] = -1; > > + perf_test_set_write_percent(vm, 100); This is a very important line of code and it's not very clear why it's here to a random reader. Please a comment here so someone doesn't have to go through the same confusion/debugging we went through to figure out why this is necessary. e.g. /* * 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); Aside from that, Reviewed-by: David Matlack <dmatlack@google.com> > perf_test_start_vcpu_threads(nr_vcpus, vcpu_worker); > > /* Allow the vCPUs to populate memory */ > @@ -269,6 +269,8 @@ 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 > @@ -341,7 +343,7 @@ 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]\n", name); > + "[-x memslots] [-w percentage]\n", name); > puts(""); > printf(" -i: specify iteration counts (default: %"PRIu64")\n", > TEST_HOST_LOOP_N); > @@ -358,10 +360,6 @@ 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"); > @@ -369,6 +367,11 @@ 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"); > puts(""); > exit(0); > } > @@ -378,10 +381,10 @@ 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, > .partition_vcpu_memory_access = true, > .backing_src = DEFAULT_VM_MEM_SRC, > .slots = 1, > + .write_percent = 100, > .random_seed = time(NULL), > }; > int opt; > @@ -393,7 +396,7 @@ int main(int argc, char *argv[]) > > guest_modes_append_default(); > > - while ((opt = getopt(argc, argv, "ghi:p:m:nb:f:v:or:s:x:")) != -1) { > + while ((opt = getopt(argc, argv, "ghi:p:m:nb:v:or:s:x:w:")) != -1) { > switch (opt) { > case 'g': > dirty_log_manual_caps = 0; > @@ -413,10 +416,11 @@ int main(int argc, char *argv[]) > case 'b': > guest_percpu_mem_size = parse_size(optarg); > break; > - case 'f': > - p.wr_fract = atoi(optarg); > - TEST_ASSERT(p.wr_fract >= 1, > - "Write fraction cannot be less than one"); > + case 'w': > + p.write_percent = atoi(optarg); > + TEST_ASSERT(p.write_percent >= 0 > + && p.write_percent <= 100, > + "Write percentage must be between 0 and 100"); > break; > case 'v': > nr_vcpus = atoi(optarg); > diff --git a/tools/testing/selftests/kvm/include/perf_test_util.h b/tools/testing/selftests/kvm/include/perf_test_util.h > index f18530984b42..f93f2ea7c6a3 100644 > --- a/tools/testing/selftests/kvm/include/perf_test_util.h > +++ b/tools/testing/selftests/kvm/include/perf_test_util.h > @@ -35,7 +35,7 @@ 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; > @@ -51,7 +51,7 @@ struct kvm_vm *perf_test_create_vm(enum vm_guest_mode mode, int 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 *)); > diff --git a/tools/testing/selftests/kvm/lib/perf_test_util.c b/tools/testing/selftests/kvm/lib/perf_test_util.c > index 4d9c7d7693d9..12a3597be1f9 100644 > --- a/tools/testing/selftests/kvm/lib/perf_test_util.c > +++ b/tools/testing/selftests/kvm/lib/perf_test_util.c > @@ -60,7 +60,7 @@ void perf_test_guest_code(uint32_t vcpu_id) > uint64_t addr = gva + (i * pta->guest_page_size); > guest_random(&rand); > > - if (i % pta->wr_fract == 0) > + if (rand % 100 < pta->write_percent) > *(uint64_t *)addr = 0x0123456789ABCDEF; > else > READ_ONCE(*(uint64_t *)addr); > @@ -118,7 +118,7 @@ struct kvm_vm *perf_test_create_vm(enum vm_guest_mode mode, int vcpus, > pr_info("Testing guest mode: %s\n", vm_guest_mode_string(mode)); > > /* Set perf_test_args defaults. */ > - pta->wr_fract = 1; > + pta->write_percent = 100; > pta->random_seed = time(NULL); > > /* > @@ -221,10 +221,10 @@ void perf_test_destroy_vm(struct kvm_vm *vm) > kvm_vm_free(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) > { > - perf_test_args.wr_fract = wr_fract; > - sync_global_to_guest(vm, perf_test_args); > + perf_test_args.write_percent = write_percent; > + sync_global_to_guest(vm, perf_test_args.write_percent); > } > > void perf_test_set_random_seed(struct kvm_vm *vm, uint32_t random_seed) > -- > 2.37.2.789.g6183377224-goog >
diff --git a/tools/testing/selftests/kvm/access_tracking_perf_test.c b/tools/testing/selftests/kvm/access_tracking_perf_test.c index d8909032317a..d86046ef3a0b 100644 --- a/tools/testing/selftests/kvm/access_tracking_perf_test.c +++ b/tools/testing/selftests/kvm/access_tracking_perf_test.c @@ -274,7 +274,7 @@ static void run_iteration(struct kvm_vm *vm, int vcpus, const char *description) static void access_memory(struct kvm_vm *vm, int vcpus, enum access_type access, const char *description) { - perf_test_set_wr_fract(vm, (access == ACCESS_READ) ? INT_MAX : 1); + perf_test_set_write_percent(vm, (access == ACCESS_READ) ? 0 : 100); iteration_work = ITERATION_ACCESS_MEMORY; run_iteration(vm, vcpus, description); } diff --git a/tools/testing/selftests/kvm/dirty_log_perf_test.c b/tools/testing/selftests/kvm/dirty_log_perf_test.c index 2f91acd94130..c2ad299b3760 100644 --- a/tools/testing/selftests/kvm/dirty_log_perf_test.c +++ b/tools/testing/selftests/kvm/dirty_log_perf_test.c @@ -122,10 +122,10 @@ 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; }; @@ -223,7 +223,6 @@ 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); guest_num_pages = (nr_vcpus * guest_percpu_mem_size) >> vm_get_page_shift(vm); guest_num_pages = vm_adjust_num_guest_pages(mode, guest_num_pages); @@ -248,6 +247,7 @@ static void run_test(enum vm_guest_mode mode, void *arg) for (vcpu_id = 0; vcpu_id < nr_vcpus; vcpu_id++) vcpu_last_completed_iteration[vcpu_id] = -1; + perf_test_set_write_percent(vm, 100); perf_test_start_vcpu_threads(nr_vcpus, vcpu_worker); /* Allow the vCPUs to populate memory */ @@ -269,6 +269,8 @@ 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 @@ -341,7 +343,7 @@ 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]\n", name); + "[-x memslots] [-w percentage]\n", name); puts(""); printf(" -i: specify iteration counts (default: %"PRIu64")\n", TEST_HOST_LOOP_N); @@ -358,10 +360,6 @@ 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"); @@ -369,6 +367,11 @@ 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"); puts(""); exit(0); } @@ -378,10 +381,10 @@ 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, .partition_vcpu_memory_access = true, .backing_src = DEFAULT_VM_MEM_SRC, .slots = 1, + .write_percent = 100, .random_seed = time(NULL), }; int opt; @@ -393,7 +396,7 @@ int main(int argc, char *argv[]) guest_modes_append_default(); - while ((opt = getopt(argc, argv, "ghi:p:m:nb:f:v:or:s:x:")) != -1) { + while ((opt = getopt(argc, argv, "ghi:p:m:nb:v:or:s:x:w:")) != -1) { switch (opt) { case 'g': dirty_log_manual_caps = 0; @@ -413,10 +416,11 @@ int main(int argc, char *argv[]) case 'b': guest_percpu_mem_size = parse_size(optarg); break; - case 'f': - p.wr_fract = atoi(optarg); - TEST_ASSERT(p.wr_fract >= 1, - "Write fraction cannot be less than one"); + case 'w': + p.write_percent = atoi(optarg); + TEST_ASSERT(p.write_percent >= 0 + && p.write_percent <= 100, + "Write percentage must be between 0 and 100"); break; case 'v': nr_vcpus = atoi(optarg); diff --git a/tools/testing/selftests/kvm/include/perf_test_util.h b/tools/testing/selftests/kvm/include/perf_test_util.h index f18530984b42..f93f2ea7c6a3 100644 --- a/tools/testing/selftests/kvm/include/perf_test_util.h +++ b/tools/testing/selftests/kvm/include/perf_test_util.h @@ -35,7 +35,7 @@ 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; @@ -51,7 +51,7 @@ struct kvm_vm *perf_test_create_vm(enum vm_guest_mode mode, int 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 *)); diff --git a/tools/testing/selftests/kvm/lib/perf_test_util.c b/tools/testing/selftests/kvm/lib/perf_test_util.c index 4d9c7d7693d9..12a3597be1f9 100644 --- a/tools/testing/selftests/kvm/lib/perf_test_util.c +++ b/tools/testing/selftests/kvm/lib/perf_test_util.c @@ -60,7 +60,7 @@ void perf_test_guest_code(uint32_t vcpu_id) uint64_t addr = gva + (i * pta->guest_page_size); guest_random(&rand); - if (i % pta->wr_fract == 0) + if (rand % 100 < pta->write_percent) *(uint64_t *)addr = 0x0123456789ABCDEF; else READ_ONCE(*(uint64_t *)addr); @@ -118,7 +118,7 @@ struct kvm_vm *perf_test_create_vm(enum vm_guest_mode mode, int vcpus, pr_info("Testing guest mode: %s\n", vm_guest_mode_string(mode)); /* Set perf_test_args defaults. */ - pta->wr_fract = 1; + pta->write_percent = 100; pta->random_seed = time(NULL); /* @@ -221,10 +221,10 @@ void perf_test_destroy_vm(struct kvm_vm *vm) kvm_vm_free(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) { - perf_test_args.wr_fract = wr_fract; - sync_global_to_guest(vm, perf_test_args); + perf_test_args.write_percent = write_percent; + sync_global_to_guest(vm, perf_test_args.write_percent); } void perf_test_set_random_seed(struct kvm_vm *vm, uint32_t random_seed)
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. Signed-off-by: Colton Lewis <coltonlewis@google.com> --- .../selftests/kvm/access_tracking_perf_test.c | 2 +- .../selftests/kvm/dirty_log_perf_test.c | 30 +++++++++++-------- .../selftests/kvm/include/perf_test_util.h | 4 +-- .../selftests/kvm/lib/perf_test_util.c | 10 +++---- 4 files changed, 25 insertions(+), 21 deletions(-)