| Message ID | 20220810175830.2175089-3-coltonlewis@google.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | KVM: selftests: Randomize memory access of dirty_log_perf_test | expand |
On Wed, Aug 10, 2022 at 05:58:29PM +0000, Colton Lewis wrote: > Randomize which pages are written vs read by using the random number Same thing here about stating what the patch does first. > table for each page modulo 100. This changes how the -w argument s/-f/-w/ Although I would love it if you renamed -f to -w in the code instead. > 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@google.com> > --- > tools/testing/selftests/kvm/dirty_log_perf_test.c | 12 +++++++----- access_tracking_perf_test.c also uses wr_fract and will need to be updated. > 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" s/fraction/percentage/ > " 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"); Mention that the implementation is probabilistic. > 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, Please rename wr_fract to e.g. write_percent to reflect the new semantics. Same goes for perf_test_set_wr_fract(), perf_test_args.wr_fract, etc. > .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"); nit: This could be combined into a single assert pretty easily. > 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 >
On Wed, Aug 10, 2022 at 04:33:44PM -0700, David Matlack wrote: > On Wed, Aug 10, 2022 at 05:58:29PM +0000, Colton Lewis wrote: > > Randomize which pages are written vs read by using the random number > > Same thing here about stating what the patch does first. Sorry -- you do state what the patch does first here. But I think it could just be a little more direct and specific. e.g. Replace the -f<fraction> option in dirty_log_perf_test.c with -w<percent>, to allow the user to specify the percentage of which pages are written. > > > 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.
On Wed, Aug 10, 2022 at 04:37:47PM -0700, David Matlack wrote: > On Wed, Aug 10, 2022 at 04:33:44PM -0700, David Matlack wrote: > > On Wed, Aug 10, 2022 at 05:58:29PM +0000, Colton Lewis wrote: > > > Randomize which pages are written vs read by using the random number > > > > Same thing here about stating what the patch does first. > > Sorry -- you do state what the patch does first here. But I think it > could just be a little more direct and specific. e.g. > > Replace the -f<fraction> option in dirty_log_perf_test.c with > -w<percent>, to allow the user to specify the percentage of which > pages are written. > > > > > > 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. Will do.
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
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@google.com> --- 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(-)