From: Ben Gardon <bgardon@google.com>
To: Yanan Wang <wangyanan55@huawei.com>
Cc: kvm <kvm@vger.kernel.org>,
linux-kselftest@vger.kernel.org,
LKML <linux-kernel@vger.kernel.org>,
Paolo Bonzini <pbonzini@redhat.com>,
Sean Christopherson <seanjc@google.com>,
Vitaly Kuznetsov <vkuznets@redhat.com>,
Arnaldo Carvalho de Melo <acme@redhat.com>,
Ingo Molnar <mingo@kernel.org>, Andrew Jones <drjones@redhat.com>,
Peter Xu <peterx@redhat.com>, Marc Zyngier <maz@kernel.org>,
wanghaibin.wang@huawei.com, yuzenghui@huawei.com
Subject: Re: [RFC PATCH v2 4/7] KVM: selftests: Add a helper to get system configured THP page size
Date: Thu, 25 Feb 2021 15:27:00 -0800 [thread overview]
Message-ID: <CANgfPd8rSmKr_G9HFqt30hFGJ9jW387yUODYH+f+BUJPv7-sCA@mail.gmail.com> (raw)
In-Reply-To: <20210225055940.18748-5-wangyanan55@huawei.com>
On Wed, Feb 24, 2021 at 10:00 PM Yanan Wang <wangyanan55@huawei.com> wrote:
>
> If we want to have some tests about transparent hugepages, the system
> configured THP hugepage size should better be known by the tests, which
> can be used for kinds of alignment or guest memory accessing of vcpus...
> So it makes sense to add a helper to get the transparent hugepage size.
>
> With VM_MEM_SRC_ANONYMOUS_THP specified in vm_userspace_mem_region_add(),
> we now stat /sys/kernel/mm/transparent_hugepage to check whether THP is
> configured in the host kernel before madvise(). Based on this, we can also
> read file /sys/kernel/mm/transparent_hugepage/hpage_pmd_size to get THP
> hugepage size.
>
> Signed-off-by: Yanan Wang <wangyanan55@huawei.com>
Reviewed-by: Ben Gardon <bgardon@google.com>
> ---
> .../testing/selftests/kvm/include/test_util.h | 2 ++
> tools/testing/selftests/kvm/lib/test_util.c | 36 +++++++++++++++++++
> 2 files changed, 38 insertions(+)
>
> diff --git a/tools/testing/selftests/kvm/include/test_util.h b/tools/testing/selftests/kvm/include/test_util.h
> index b7f41399f22c..ef24c76ba89a 100644
> --- a/tools/testing/selftests/kvm/include/test_util.h
> +++ b/tools/testing/selftests/kvm/include/test_util.h
> @@ -78,6 +78,8 @@ struct vm_mem_backing_src_alias {
> enum vm_mem_backing_src_type type;
> };
>
> +bool thp_configured(void);
> +size_t get_trans_hugepagesz(void);
> void backing_src_help(void);
> enum vm_mem_backing_src_type parse_backing_src_type(const char *type_name);
>
> diff --git a/tools/testing/selftests/kvm/lib/test_util.c b/tools/testing/selftests/kvm/lib/test_util.c
> index c7c0627c6842..f2d133f76c67 100644
> --- a/tools/testing/selftests/kvm/lib/test_util.c
> +++ b/tools/testing/selftests/kvm/lib/test_util.c
> @@ -10,6 +10,7 @@
> #include <limits.h>
> #include <stdlib.h>
> #include <time.h>
> +#include <sys/stat.h>
> #include "linux/kernel.h"
>
> #include "test_util.h"
> @@ -117,6 +118,41 @@ const struct vm_mem_backing_src_alias backing_src_aliases[] = {
> {"anonymous_hugetlb", VM_MEM_SRC_ANONYMOUS_HUGETLB,},
> };
>
> +bool thp_configured(void)
> +{
> + int ret;
> + struct stat statbuf;
> +
> + ret = stat("/sys/kernel/mm/transparent_hugepage", &statbuf);
> + TEST_ASSERT(ret == 0 || (ret == -1 && errno == ENOENT),
> + "Error in stating /sys/kernel/mm/transparent_hugepage: %d",
> + errno);
> +
> + return ret == 0;
> +}
> +
> +size_t get_trans_hugepagesz(void)
> +{
> + size_t size;
> + char buf[16];
> + FILE *f;
> +
> + TEST_ASSERT(thp_configured(), "THP is not configured in host kernel");
> +
> + f = fopen("/sys/kernel/mm/transparent_hugepage/hpage_pmd_size", "r");
> + TEST_ASSERT(f != NULL,
> + "Error in opening transparent_hugepage/hpage_pmd_size: %d",
> + errno);
> +
> + if (fread(buf, sizeof(char), sizeof(buf), f) == 0) {
> + fclose(f);
> + TEST_FAIL("Unable to read transparent_hugepage/hpage_pmd_size");
> + }
> +
> + size = strtoull(buf, NULL, 10);
> + return size;
> +}
> +
> void backing_src_help(void)
> {
> int i;
> --
> 2.19.1
>
next prev parent reply other threads:[~2021-02-25 23:28 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-02-25 5:59 [RFC PATCH v2 0/7] Some improvement and a new test for kvm page table Yanan Wang
2021-02-25 5:59 ` [RFC PATCH v2 1/7] tools include: sync head files of mmap flag encodings about hugetlb Yanan Wang
2021-02-25 5:59 ` [RFC PATCH v2 2/7] KVM: selftests: Use flag CLOCK_MONOTONIC_RAW for timing Yanan Wang
2021-02-25 18:54 ` Andrew Jones
2021-02-26 2:49 ` wangyanan (Y)
2021-02-25 5:59 ` [RFC PATCH v2 3/7] KVM: selftests: Make a generic helper to get vm guest mode strings Yanan Wang
2021-02-25 18:55 ` Andrew Jones
2021-02-26 5:56 ` wangyanan (Y)
2021-02-25 5:59 ` [RFC PATCH v2 4/7] KVM: selftests: Add a helper to get system configured THP page size Yanan Wang
2021-02-25 23:27 ` Ben Gardon [this message]
2021-02-25 5:59 ` [RFC PATCH v2 5/7] KVM: selftests: List all hugetlb src types specified with page sizes Yanan Wang
2021-02-25 23:42 ` Ben Gardon
2021-02-26 5:45 ` wangyanan (Y)
2021-02-25 5:59 ` [RFC PATCH v2 6/7] KVM: selftests: Adapt vm_userspace_mem_region_add to new helpers Yanan Wang
2021-02-25 23:44 ` Ben Gardon
2021-02-26 5:48 ` wangyanan (Y)
2021-02-25 5:59 ` [RFC PATCH v2 7/7] KVM: selftests: Add a test for kvm page table code Yanan Wang
2021-02-25 23:45 ` [RFC PATCH v2 0/7] Some improvement and a new test for kvm page table Ben Gardon
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