diff --git a/tools/testing/selftests/kvm/dirty_log_perf_test.c b/tools/testing/selftests/kvm/dirty_log_perf_test.c index 4d639683b8efa..0612158329aa0 100644 --- a/tools/testing/selftests/kvm/dirty_log_perf_test.c +++ b/tools/testing/selftests/kvm/dirty_log_perf_test.c @@ -353,7 +353,7 @@ static void help(char *name) puts(""); printf("usage: %s [-h] [-i iterations] [-p offset] [-g] " "[-m mode] [-n] [-b vcpu bytes] [-v vcpus] [-o] [-s mem type]" - "[-x memslots]\n", name); + "[-x memslots] [-c physical cpus to run test on]\n", name); puts(""); printf(" -i: specify iteration counts (default: %"PRIu64")\n", TEST_HOST_LOOP_N); @@ -383,6 +383,17 @@ 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(" -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" + " ). If used, entries must be provided for all\n" + " vCPUs, i.e. pinning vCPUs is all or nothing.\n\n" + " E.g. to create 3 vCPUs, pin vCPU0=>pCPU22, vCPU1=>pCPU23,\n" + " vCPU2=>pCPU24, and pin the application task to pCPU50:\n\n" + " ./dirty_log_perf_test -v 3 -c 22,23,24,50\n\n" + " To leave the application task unpinned, drop the final entry:\n\n" + " ./dirty_log_perf_test -v 3 -c 22,23,24\n\n" + " (default: no pinning)\n"); puts(""); exit(0); } @@ -390,6 +401,7 @@ static void help(char *name) int main(int argc, char *argv[]) { int max_vcpus = kvm_check_cap(KVM_CAP_MAX_VCPUS); + const char *pcpu_list = NULL; struct test_params p = { .iterations = TEST_HOST_LOOP_N, .wr_fract = 1, @@ -406,11 +418,14 @@ int main(int argc, char *argv[]) guest_modes_append_default(); - while ((opt = getopt(argc, argv, "b:ef:ghi:m:nop:s:v:x:")) != -1) { + while ((opt = getopt(argc, argv, "b:c:ef:ghi:m:nop:s:v:x:")) != -1) { switch (opt) { case 'b': guest_percpu_mem_size = parse_size(optarg); break; + case 'c': + pcpu_list = optarg; + break; case 'e': /* 'e' is for evil. */ run_vcpus_while_disabling_dirty_logging = true; @@ -456,6 +471,12 @@ int main(int argc, char *argv[]) } } + if (pcpu_list) { + kvm_parse_vcpu_pinning(pcpu_list, perf_test_args.vcpu_to_pcpu, + nr_vcpus); + perf_test_args.pin_vcpus = true; + } + TEST_ASSERT(p.iterations >= 2, "The test should have at least two iterations"); pr_info("Test iterations: %"PRIu64"\n", p.iterations); diff --git a/tools/testing/selftests/kvm/include/kvm_util_base.h b/tools/testing/selftests/kvm/include/kvm_util_base.h index e42a09cd24a04..3bf2333ef95d2 100644 --- a/tools/testing/selftests/kvm/include/kvm_util_base.h +++ b/tools/testing/selftests/kvm/include/kvm_util_base.h @@ -688,6 +688,10 @@ static inline struct kvm_vm *vm_create_with_one_vcpu(struct kvm_vcpu **vcpu, struct kvm_vcpu *vm_recreate_with_one_vcpu(struct kvm_vm *vm); +void kvm_pin_this_task_to_pcpu(uint32_t pcpu); +void kvm_parse_vcpu_pinning(const char *pcpus_string, uint32_t vcpu_to_pcpu[], + int nr_vcpus); + unsigned long vm_compute_max_gfn(struct kvm_vm *vm); unsigned int vm_calc_num_guest_pages(enum vm_guest_mode mode, size_t size); unsigned int vm_num_host_pages(enum vm_guest_mode mode, unsigned int num_guest_pages); diff --git a/tools/testing/selftests/kvm/include/perf_test_util.h b/tools/testing/selftests/kvm/include/perf_test_util.h index eaa88df0555a8..849c875dd0ffa 100644 --- a/tools/testing/selftests/kvm/include/perf_test_util.h +++ b/tools/testing/selftests/kvm/include/perf_test_util.h @@ -39,6 +39,10 @@ struct perf_test_args { /* Run vCPUs in L2 instead of L1, if the architecture supports it. */ bool nested; + /* True if all vCPUs are pinned to pCPUs */ + bool pin_vcpus; + /* The vCPU=>pCPU pinning map. Only valid if pin_vcpus is true. */ + uint32_t vcpu_to_pcpu[KVM_MAX_VCPUS]; struct perf_test_vcpu_args vcpu_args[KVM_MAX_VCPUS]; }; diff --git a/tools/testing/selftests/kvm/lib/kvm_util.c b/tools/testing/selftests/kvm/lib/kvm_util.c index f1cb1627161fd..3b7710fb37840 100644 --- a/tools/testing/selftests/kvm/lib/kvm_util.c +++ b/tools/testing/selftests/kvm/lib/kvm_util.c @@ -11,6 +11,7 @@ #include "processor.h" #include +#include #include #include #include @@ -443,6 +444,59 @@ struct kvm_vcpu *vm_recreate_with_one_vcpu(struct kvm_vm *vm) return vm_vcpu_recreate(vm, 0); } +void kvm_pin_this_task_to_pcpu(uint32_t pcpu) +{ + cpu_set_t mask; + int r; + + CPU_ZERO(&mask); + CPU_SET(pcpu, &mask); + r = sched_setaffinity(0, sizeof(mask), &mask); + TEST_ASSERT(!r, "sched_setaffinity() failed for pCPU '%u'.\n", pcpu); +} + +static uint32_t parse_pcpu(const char *cpu_str, const cpu_set_t *allowed_mask) +{ + uint32_t pcpu = atoi_non_negative("CPU number", cpu_str); + + TEST_ASSERT(CPU_ISSET(pcpu, allowed_mask), + "Not allowed to run on pCPU '%d', check cgroups?\n", pcpu); + return pcpu; +} + +void kvm_parse_vcpu_pinning(const char *pcpus_string, uint32_t vcpu_to_pcpu[], + int nr_vcpus) +{ + cpu_set_t allowed_mask; + char *cpu, *cpu_list; + char delim[2] = ","; + int i, r; + + cpu_list = strdup(pcpus_string); + TEST_ASSERT(cpu_list, "strdup() allocation failed.\n"); + + r = sched_getaffinity(0, sizeof(allowed_mask), &allowed_mask); + TEST_ASSERT(!r, "sched_getaffinity() failed"); + + cpu = strtok(cpu_list, delim); + + /* 1. Get all pcpus for vcpus. */ + for (i = 0; i < nr_vcpus; i++) { + TEST_ASSERT(cpu, "pCPU not provided for vCPU '%d'\n", i); + vcpu_to_pcpu[i] = parse_pcpu(cpu, &allowed_mask); + cpu = strtok(NULL, delim); + } + + /* 2. Check if the main worker needs to be pinned. */ + if (cpu) { + kvm_pin_this_task_to_pcpu(parse_pcpu(cpu, &allowed_mask)); + cpu = strtok(NULL, delim); + } + + TEST_ASSERT(!cpu, "pCPU list contains trailing garbage characters '%s'", cpu); + free(cpu_list); +} + /* * Userspace Memory Region Find * diff --git a/tools/testing/selftests/kvm/lib/perf_test_util.c b/tools/testing/selftests/kvm/lib/perf_test_util.c index 9618b37c66f7e..3a1d0a44419b0 100644 --- a/tools/testing/selftests/kvm/lib/perf_test_util.c +++ b/tools/testing/selftests/kvm/lib/perf_test_util.c @@ -2,6 +2,8 @@ /* * Copyright (C) 2020, Google LLC. */ +#define _GNU_SOURCE + #include #include "kvm_util.h" @@ -243,6 +245,10 @@ void __weak perf_test_setup_nested(struct kvm_vm *vm, int nr_vcpus, struct kvm_v static void *vcpu_thread_main(void *data) { struct vcpu_thread *vcpu = data; + int vcpu_idx = vcpu->vcpu_idx; + + if (perf_test_args.pin_vcpus) + kvm_pin_this_task_to_pcpu(perf_test_args.vcpu_to_pcpu[vcpu_idx]); WRITE_ONCE(vcpu->running, true); @@ -255,7 +261,7 @@ static void *vcpu_thread_main(void *data) while (!READ_ONCE(all_vcpu_threads_running)) ; - vcpu_thread_fn(&perf_test_args.vcpu_args[vcpu->vcpu_idx]); + vcpu_thread_fn(&perf_test_args.vcpu_args[vcpu_idx]); return NULL; }