iv/linux
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

KVM: selftests: Time guest demand paging

Browse Source 
In order to quantify demand paging performance, time guest execution
during demand paging.

Signed-off-by: Ben Gardon <bgardon@google.com>
[Move timespec-diff to test_util.h]
Signed-off-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Ben Gardon 2020-01-23 10:04:34 -08:00 committed by Paolo Bonzini
parent 018494e6d8
commit f09205b998
3 changed files with 72 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

50
tools/testing/selftests/kvm/demand_paging_test.c
View File

@ -35,6 +35,12 @@
#define DEFAULT_GUEST_TEST_MEM_SIZE (1 << 30) /* 1G */
#ifdef PRINT_PER_PAGE_UPDATES
#define PER_PAGE_DEBUG(...) DEBUG(__VA_ARGS__)
#else
#define PER_PAGE_DEBUG(...)
#endif
#ifdef PRINT_PER_VCPU_UPDATES
#define PER_VCPU_DEBUG(...) DEBUG(__VA_ARGS__)
#else
@ -111,10 +117,14 @@ static void *vcpu_worker(void *data)
struct kvm_vm *vm = args->vm;
int vcpu_id = args->vcpu_id;
struct kvm_run *run;
struct timespec start;
struct timespec end;
vcpu_args_set(vm, vcpu_id, 1, vcpu_id);
run = vcpu_state(vm, vcpu_id);
clock_gettime(CLOCK_MONOTONIC, &start);
/* Let the guest access its memory */
ret = _vcpu_run(vm, vcpu_id);
TEST_ASSERT(ret == 0, "vcpu_run failed: %d\n", ret);
@ -124,6 +134,11 @@ static void *vcpu_worker(void *data)
exit_reason_str(run->exit_reason));
}
clock_gettime(CLOCK_MONOTONIC, &end);
PER_VCPU_DEBUG("vCPU %d execution time: %lld.%.9lds\n", vcpu_id,
(long long)(timespec_diff(start, end).tv_sec),
timespec_diff(start, end).tv_nsec);
return NULL;
}
@ -161,6 +176,8 @@ static struct kvm_vm *create_vm(enum vm_guest_mode mode, int vcpus,
static int handle_uffd_page_request(int uffd, uint64_t addr)
{
pid_t tid;
struct timespec start;
struct timespec end;
struct uffdio_copy copy;
int r;
@ -171,6 +188,8 @@ static int handle_uffd_page_request(int uffd, uint64_t addr)
copy.len = host_page_size;
copy.mode = 0;
clock_gettime(CLOCK_MONOTONIC, &start);
r = ioctl(uffd, UFFDIO_COPY, &copy);
if (r == -1) {
DEBUG("Failed Paged in 0x%lx from thread %d with errno: %d\n",
@ -178,6 +197,13 @@ static int handle_uffd_page_request(int uffd, uint64_t addr)
return r;
}
clock_gettime(CLOCK_MONOTONIC, &end);
PER_PAGE_DEBUG("UFFDIO_COPY %d \t%lld ns\n", tid,
(long long)timespec_to_ns(timespec_diff(start, end)));
PER_PAGE_DEBUG("Paged in %ld bytes at 0x%lx from thread %d\n",
host_page_size, addr, tid);
return 0;
}
@ -196,7 +222,10 @@ static void *uffd_handler_thread_fn(void *arg)
int pipefd = uffd_args->pipefd;
useconds_t delay = uffd_args->delay;
int64_t pages = 0;
struct timespec start;
struct timespec end;
clock_gettime(CLOCK_MONOTONIC, &start);
while (!quit_uffd_thread) {
struct uffd_msg msg;
struct pollfd pollfd[2];
@ -264,6 +293,13 @@ static void *uffd_handler_thread_fn(void *arg)
pages++;
}
clock_gettime(CLOCK_MONOTONIC, &end);
PER_VCPU_DEBUG("userfaulted %ld pages over %lld.%.9lds. (%f/sec)\n",
pages, (long long)(timespec_diff(start, end).tv_sec),
timespec_diff(start, end).tv_nsec, pages /
((double)timespec_diff(start, end).tv_sec +
(double)timespec_diff(start, end).tv_nsec / 100000000.0));
return NULL;
}
@ -328,6 +364,8 @@ static void run_test(enum vm_guest_mode mode, bool use_uffd,
uint64_t guest_num_pages;
int vcpu_id;
int r;
struct timespec start;
struct timespec end;
vm = create_vm(mode, vcpus, vcpu_memory_bytes);
@ -369,7 +407,6 @@ static void run_test(enum vm_guest_mode mode, bool use_uffd,
DEBUG("guest physical test memory offset: 0x%lx\n",
guest_test_phys_mem);
/* Add an extra memory slot for testing demand paging */
vm_userspace_mem_region_add(vm, VM_MEM_SRC_ANONYMOUS,
guest_test_phys_mem,
@ -451,6 +488,8 @@ static void run_test(enum vm_guest_mode mode, bool use_uffd,
DEBUG("Finished creating vCPUs and starting uffd threads\n");
clock_gettime(CLOCK_MONOTONIC, &start);
for (vcpu_id = 0; vcpu_id < vcpus; vcpu_id++) {
pthread_create(&vcpu_threads[vcpu_id], NULL, vcpu_worker,
&vcpu_args[vcpu_id]);
@ -466,6 +505,8 @@ static void run_test(enum vm_guest_mode mode, bool use_uffd,
DEBUG("All vCPU threads joined\n");
clock_gettime(CLOCK_MONOTONIC, &end);
if (use_uffd) {
char c;
@ -478,6 +519,13 @@ static void run_test(enum vm_guest_mode mode, bool use_uffd,
}
}
DEBUG("Total guest execution time: %lld.%.9lds\n",
(long long)(timespec_diff(start, end).tv_sec),
timespec_diff(start, end).tv_nsec);
DEBUG("Overall demand paging rate: %f pgs/sec\n",
guest_num_pages / ((double)timespec_diff(start, end).tv_sec +
(double)timespec_diff(start, end).tv_nsec / 100000000.0));
ucall_uninit(vm);
kvm_vm_free(vm);

3
tools/testing/selftests/kvm/include/test_util.h
View File

@ -41,4 +41,7 @@ void test_assert(bool exp, const char *exp_str,
size_t parse_size(const char *size);
int64_t timespec_to_ns(struct timespec ts);
struct timespec timespec_diff(struct timespec start, struct timespec end);
#endif /* SELFTEST_KVM_TEST_UTIL_H */

20
tools/testing/selftests/kvm/lib/test_util.c
View File

@ -49,3 +49,23 @@ size_t parse_size(const char *size)
return base << shift;
}
int64_t timespec_to_ns(struct timespec ts)
{
return (int64_t)ts.tv_nsec + 1000000000LL * (int64_t)ts.tv_sec;
}
struct timespec timespec_diff(struct timespec start, struct timespec end)
{
struct timespec temp;
if ((end.tv_nsec - start.tv_nsec) < 0) {
temp.tv_sec = end.tv_sec - start.tv_sec - 1;
temp.tv_nsec = 1000000000LL + end.tv_nsec - start.tv_nsec;
} else {
temp.tv_sec = end.tv_sec - start.tv_sec;
temp.tv_nsec = end.tv_nsec - start.tv_nsec;
}
return temp;
}