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authorBen Gardon <bgardon@google.com>2022-06-13 21:25:23 +0000
committerPaolo Bonzini <pbonzini@redhat.com>2022-06-24 04:51:51 -0400
commit83f6e109f562063ab7a1f54d99bcab2858b09ead (patch)
treec9ad1742db44dd9d4d597cd28ce94e94e266180e /tools/testing/selftests/kvm/lib/kvm_util.c
parentKVM: selftests: Test disabling NX hugepages on a VM (diff)
downloadlinux-dev-83f6e109f562063ab7a1f54d99bcab2858b09ead.tar.xz
linux-dev-83f6e109f562063ab7a1f54d99bcab2858b09ead.zip
KVM: selftests: Cache binary stats metadata for duration of test
In order to improve performance across multiple reads of VM stats, cache the stats metadata in the VM struct. Signed-off-by: Ben Gardon <bgardon@google.com> Message-Id: <20220613212523.3436117-11-bgardon@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'tools/testing/selftests/kvm/lib/kvm_util.c')
-rw-r--r--tools/testing/selftests/kvm/lib/kvm_util.c32
1 files changed, 17 insertions, 15 deletions
diff --git a/tools/testing/selftests/kvm/lib/kvm_util.c b/tools/testing/selftests/kvm/lib/kvm_util.c
index 5a0fd368503f..768f3bce0161 100644
--- a/tools/testing/selftests/kvm/lib/kvm_util.c
+++ b/tools/testing/selftests/kvm/lib/kvm_util.c
@@ -547,6 +547,12 @@ void kvm_vm_free(struct kvm_vm *vmp)
if (vmp == NULL)
return;
+ /* Free cached stats metadata and close FD */
+ if (vmp->stats_fd) {
+ free(vmp->stats_desc);
+ close(vmp->stats_fd);
+ }
+
/* Free userspace_mem_regions. */
hash_for_each_safe(vmp->regions.slot_hash, ctr, node, region, slot_node)
__vm_mem_region_delete(vmp, region, false);
@@ -1935,32 +1941,28 @@ void read_stat_data(int stats_fd, struct kvm_stats_header *header,
void __vm_get_stat(struct kvm_vm *vm, const char *stat_name, uint64_t *data,
size_t max_elements)
{
- struct kvm_stats_desc *stats_desc;
- struct kvm_stats_header header;
struct kvm_stats_desc *desc;
size_t size_desc;
- int stats_fd;
int i;
- stats_fd = vm_get_stats_fd(vm);
-
- read_stats_header(stats_fd, &header);
-
- stats_desc = read_stats_descriptors(stats_fd, &header);
+ if (!vm->stats_fd) {
+ vm->stats_fd = vm_get_stats_fd(vm);
+ read_stats_header(vm->stats_fd, &vm->stats_header);
+ vm->stats_desc = read_stats_descriptors(vm->stats_fd,
+ &vm->stats_header);
+ }
- size_desc = get_stats_descriptor_size(&header);
+ size_desc = get_stats_descriptor_size(&vm->stats_header);
- for (i = 0; i < header.num_desc; ++i) {
- desc = (void *)stats_desc + (i * size_desc);
+ for (i = 0; i < vm->stats_header.num_desc; ++i) {
+ desc = (void *)vm->stats_desc + (i * size_desc);
if (strcmp(desc->name, stat_name))
continue;
- read_stat_data(stats_fd, &header, desc, data, max_elements);
+ read_stat_data(vm->stats_fd, &vm->stats_header, desc,
+ data, max_elements);
break;
}
-
- free(stats_desc);
- close(stats_fd);
}