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KVM: selftests: Cache binary stats metadata for duration of test

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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>
This commit is contained in:
Ben Gardon 2022-06-13 21:25:23 +00:00 committed by Paolo Bonzini
parent b774da3f2e
commit 83f6e109f5
2 changed files with 22 additions and 15 deletions
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5
tools/testing/selftests/kvm/include/kvm_util_base.h
View File

@ -84,6 +84,11 @@ struct kvm_vm {
vm_vaddr_t idt;
vm_vaddr_t handlers;
uint32_t dirty_ring_size;
/* Cache of information for binary stats interface */
int stats_fd;
struct kvm_stats_header stats_header;
struct kvm_stats_desc *stats_desc;
};

32
tools/testing/selftests/kvm/lib/kvm_util.c
View File

@ -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);
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);
}
read_stats_header(stats_fd, &header);
size_desc = get_stats_descriptor_size(&vm->stats_header);
stats_desc = read_stats_descriptors(stats_fd, &header);
size_desc = get_stats_descriptor_size(&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);
}