From: Ben Gardon <bgardon@google.com>
To: kvm@vger.kernel.org, linux-kselftest@vger.kernel.org
Cc: Paolo Bonzini <pbonzini@redhat.com>,
Cannon Matthews <cannonmatthews@google.com>,
Peter Xu <peterx@redhat.com>, Andrew Jones <drjones@redhat.com>,
Ben Gardon <bgardon@google.com>
Subject: [PATCH 6/9] KVM: selftests: Time guest demand paging
Date: Fri, 27 Sep 2019 09:18:34 -0700 [thread overview]
Message-ID: <20190927161836.57978-7-bgardon@google.com> (raw)
In-Reply-To: <20190927161836.57978-1-bgardon@google.com>
In order to quantify demand paging performance, time guest execution
during demand paging.
Signed-off-by: Ben Gardon <bgardon@google.com>
---
.../selftests/kvm/demand_paging_test.c | 68 +++++++++++++++++++
1 file changed, 68 insertions(+)
diff --git a/tools/testing/selftests/kvm/demand_paging_test.c b/tools/testing/selftests/kvm/demand_paging_test.c
index f8afc0683c346..fe6c5a4f8b8c2 100644
--- a/tools/testing/selftests/kvm/demand_paging_test.c
+++ b/tools/testing/selftests/kvm/demand_paging_test.c
@@ -34,6 +34,12 @@
#define __NR_userfaultfd 323
+#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
@@ -64,6 +70,26 @@ static uint64_t guest_test_phys_mem;
*/
static uint64_t guest_test_virt_mem = DEFAULT_GUEST_TEST_MEM;
+int64_t to_ns(struct timespec ts)
+{
+ return (int64_t)ts.tv_nsec + 1000000000LL * (int64_t)ts.tv_sec;
+}
+
+struct 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 = 1000000000 + 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;
+}
+
/*
* Continuously write to the first 8 bytes of each page in the demand paging
* memory region.
@@ -98,11 +124,15 @@ static void *vcpu_worker(void *data)
uint64_t gva = args->gva;
uint64_t pages = args->pages;
struct kvm_run *run;
+ struct timespec start;
+ struct timespec end;
vcpu_args_set(vm, vcpu_id, 2, gva, pages);
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);
@@ -112,6 +142,11 @@ 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)(diff(start, end).tv_sec),
+ diff(start, end).tv_nsec);
+
return NULL;
}
@@ -147,6 +182,8 @@ 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;
@@ -157,6 +194,8 @@ 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, ©);
if (r == -1) {
DEBUG("Failed Paged in 0x%lx from thread %d with errno: %d\n",
@@ -164,6 +203,13 @@ 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)to_ns(diff(start, end)));
+ PER_PAGE_DEBUG("Paged in %ld bytes at 0x%lx from thread %d\n",
+ host_page_size, addr, tid);
+
return 0;
}
@@ -178,7 +224,10 @@ static void *uffd_handler_thread_fn(void *arg)
struct uffd_handler_args *uffd_args = (struct uffd_handler_args *)arg;
int uffd = uffd_args->uffd;
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[1];
@@ -234,6 +283,13 @@ 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)(diff(start, end).tv_sec),
+ diff(start, end).tv_nsec, pages /
+ ((double)diff(start, end).tv_sec +
+ (double)diff(start, end).tv_nsec / 100000000.0));
+
return NULL;
}
@@ -293,6 +349,8 @@ static void run_test(enum vm_guest_mode mode, int vcpus, uint64_t vcpu_wss)
uint64_t guest_num_pages;
int vcpu_id;
int r;
+ struct timespec start;
+ struct timespec end;
vm = create_vm(mode, vcpus, vcpu_wss);
@@ -402,6 +460,8 @@ static void run_test(enum vm_guest_mode mode, int vcpus, uint64_t vcpu_wss)
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]);
@@ -417,11 +477,19 @@ static void run_test(enum vm_guest_mode mode, int vcpus, uint64_t vcpu_wss)
DEBUG("All vCPU threads joined\n");
+ clock_gettime(CLOCK_MONOTONIC, &end);
+
/* Tell the user fault fd handler thread to quit */
quit_uffd_thread = true;
for (vcpu_id = 0; vcpu_id < vcpus; vcpu_id++)
pthread_join(uffd_handler_threads[vcpu_id], NULL);
+ DEBUG("Total guest execution time: %lld.%.9lds\n",
+ (long long)(diff(start, end).tv_sec), diff(start, end).tv_nsec);
+ DEBUG("Overall demand paging rate: %f pgs/sec\n",
+ guest_num_pages / ((double)diff(start, end).tv_sec +
+ (double)diff(start, end).tv_nsec / 100000000.0));
+
ucall_uninit(vm);
kvm_vm_free(vm);
--
2.23.0.444.g18eeb5a265-goog
next prev parent reply other threads:[~2019-09-27 16:18 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-09-27 16:18 [PATCH 0/9] Create a userfaultfd demand paging test Ben Gardon
2019-09-27 16:18 ` [PATCH 1/9] KVM: selftests: Create a " Ben Gardon
2019-09-27 16:18 ` [PATCH 2/9] KVM: selftests: Add demand paging content to the " Ben Gardon
2019-09-29 7:11 ` Peter Xu
2019-09-27 16:18 ` [PATCH 3/9] KVM: selftests: Add memory size parameter " Ben Gardon
2019-09-27 16:18 ` [PATCH 4/9] KVM: selftests: Pass args to vCPU instead of using globals Ben Gardon
2019-10-03 7:38 ` Andrew Jones
2019-09-27 16:18 ` [PATCH 5/9] KVM: selftests: Support multiple vCPUs in demand paging test Ben Gardon
2019-09-27 16:18 ` Ben Gardon [this message]
2019-09-27 16:18 ` [PATCH 7/9] KVM: selftests: Add parameter to _vm_create for memslot 0 base paddr Ben Gardon
2019-10-03 8:10 ` Andrew Jones
2019-09-27 16:18 ` [PATCH 8/9] KVM: selftests: Support large VMs in demand paging test Ben Gardon
2019-09-29 7:22 ` [PATCH 0/9] Create a userfaultfd " Peter Xu
2019-09-30 17:02 ` Ben Gardon
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