From 83f6e109f562063ab7a1f54d99bcab2858b09ead Mon Sep 17 00:00:00 2001 From: Ben Gardon Date: Mon, 13 Jun 2022 21:25:23 +0000 Subject: 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 Message-Id: <20220613212523.3436117-11-bgardon@google.com> Signed-off-by: Paolo Bonzini --- .../testing/selftests/kvm/include/kvm_util_base.h | 5 ++++ tools/testing/selftests/kvm/lib/kvm_util.c | 32 ++++++++++++---------- 2 files changed, 22 insertions(+), 15 deletions(-) (limited to 'tools/testing/selftests') diff --git a/tools/testing/selftests/kvm/include/kvm_util_base.h b/tools/testing/selftests/kvm/include/kvm_util_base.h index fd2b52850b29..b78e3c7a2566 100644 --- a/tools/testing/selftests/kvm/include/kvm_util_base.h +++ b/tools/testing/selftests/kvm/include/kvm_util_base.h @@ -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; }; 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); } -- cgit v1.2.3-59-g8ed1b