Messages in this thread | | | Subject | Re: [RFC PATCH v2 6/7] KVM: selftests: Adapt vm_userspace_mem_region_add to new helpers | From | "wangyanan (Y)" <> | Date | Fri, 26 Feb 2021 13:48:44 +0800 |
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On 2021/2/26 7:44, Ben Gardon wrote: > On Wed, Feb 24, 2021 at 10:03 PM Yanan Wang <wangyanan55@huawei.com> wrote: >> With VM_MEM_SRC_ANONYMOUS_THP specified in vm_userspace_mem_region_add(), >> we have to get the transparent hugepage size for HVA alignment. With the >> new helpers, we can use get_backing_src_pagesz() to check whether THP is >> configured and then get the exact configured hugepage size. >> >> As different architectures may have different THP page sizes configured, >> this can get the accurate THP page sizes on any platform. >> >> Signed-off-by: Yanan Wang <wangyanan55@huawei.com> >> --- >> tools/testing/selftests/kvm/lib/kvm_util.c | 27 +++++++--------------- >> 1 file changed, 8 insertions(+), 19 deletions(-) >> >> diff --git a/tools/testing/selftests/kvm/lib/kvm_util.c b/tools/testing/selftests/kvm/lib/kvm_util.c >> index b91c8e3a7ee1..0105fbfed036 100644 >> --- a/tools/testing/selftests/kvm/lib/kvm_util.c >> +++ b/tools/testing/selftests/kvm/lib/kvm_util.c >> @@ -18,7 +18,6 @@ >> #include <unistd.h> >> #include <linux/kernel.h> >> >> -#define KVM_UTIL_PGS_PER_HUGEPG 512 >> #define KVM_UTIL_MIN_PFN 2 >> >> /* Aligns x up to the next multiple of size. Size must be a power of 2. */ >> @@ -686,7 +685,7 @@ void vm_userspace_mem_region_add(struct kvm_vm *vm, >> { >> int ret; >> struct userspace_mem_region *region; >> - size_t huge_page_size = KVM_UTIL_PGS_PER_HUGEPG * vm->page_size; >> + size_t backing_src_pagesz = get_backing_src_pagesz(src_type); >> size_t alignment; >> >> TEST_ASSERT(vm_adjust_num_guest_pages(vm->mode, npages) == npages, >> @@ -748,7 +747,7 @@ void vm_userspace_mem_region_add(struct kvm_vm *vm, >> #endif >> >> if (src_type == VM_MEM_SRC_ANONYMOUS_THP) >> - alignment = max(huge_page_size, alignment); >> + alignment = max(backing_src_pagesz, alignment); >> >> /* Add enough memory to align up if necessary */ >> if (alignment > 1) >> @@ -767,22 +766,12 @@ void vm_userspace_mem_region_add(struct kvm_vm *vm, >> region->host_mem = align(region->mmap_start, alignment); >> >> /* As needed perform madvise */ >> - if (src_type == VM_MEM_SRC_ANONYMOUS || src_type == VM_MEM_SRC_ANONYMOUS_THP) { >> - struct stat statbuf; >> - >> - ret = stat("/sys/kernel/mm/transparent_hugepage", &statbuf); >> - TEST_ASSERT(ret == 0 || (ret == -1 && errno == ENOENT), >> - "stat /sys/kernel/mm/transparent_hugepage"); >> - >> - TEST_ASSERT(ret == 0 || src_type != VM_MEM_SRC_ANONYMOUS_THP, >> - "VM_MEM_SRC_ANONYMOUS_THP requires THP to be configured in the host kernel"); >> - >> - if (ret == 0) { >> - ret = madvise(region->host_mem, npages * vm->page_size, >> - src_type == VM_MEM_SRC_ANONYMOUS ? MADV_NOHUGEPAGE : MADV_HUGEPAGE); >> - TEST_ASSERT(ret == 0, "madvise failed, addr: %p length: 0x%lx src_type: %x", >> - region->host_mem, npages * vm->page_size, src_type); >> - } >> + if (src_type <= VM_MEM_SRC_ANONYMOUS_THP && thp_configured()) { > This check relies on an unstated property of the backing src type > enums where VM_MEM_SRC_ANONYMOUS and VM_MEM_SRC_ANONYMOUS_THP are > declared first. > It would probably be more readable for folks if the check was explicit: > if ((src_type == VM_MEM_SRC_ANONYMOUS || src_type == > VM_MEM_SRC_ANONYMOUS_THP) && thp_configured()) { > Yes, this makes sense, I will fix it.
Thanks,
Yanan
>> + ret = madvise(region->host_mem, npages * vm->page_size, >> + src_type == VM_MEM_SRC_ANONYMOUS ? MADV_NOHUGEPAGE : MADV_HUGEPAGE); >> + TEST_ASSERT(ret == 0, "madvise failed, addr: %p length: 0x%lx src_type: %s", >> + region->host_mem, npages * vm->page_size, >> + vm_mem_backing_src_alias(src_type)->name); >> } >> >> region->unused_phy_pages = sparsebit_alloc(); >> -- >> 2.19.1 >> > .
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