@@ -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"
+ " <nr_vcpus + 1>). 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);
@@ -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);
@@ -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];
};
@@ -11,6 +11,7 @@
#include "processor.h"
#include <assert.h>
+#include <sched.h>
#include <sys/mman.h>
#include <sys/types.h>
#include <sys/stat.h>
@@ -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
*
@@ -2,6 +2,8 @@
/*
* Copyright (C) 2020, Google LLC.
*/
+#define _GNU_SOURCE
+
#include <inttypes.h>
#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;
}