From: "wangyanan (Y)" <wangyanan55@huawei.com>
To: Andrew Jones <drjones@redhat.com>
Cc: <kvm@vger.kernel.org>, <linux-kselftest@vger.kernel.org>,
<linux-kernel@vger.kernel.org>,
Paolo Bonzini <pbonzini@redhat.com>,
"Ben Gardon" <bgardon@google.com>,
Sean Christopherson <seanjc@google.com>,
"Vitaly Kuznetsov" <vkuznets@redhat.com>,
Peter Xu <peterx@redhat.com>, Marc Zyngier <maz@kernel.org>,
Ingo Molnar <mingo@kernel.org>,
Adrian Hunter <adrian.hunter@intel.com>,
Jiri Olsa <jolsa@redhat.com>,
"Arnaldo Carvalho de Melo" <acme@redhat.com>,
Arnd Bergmann <arnd@arndb.de>,
Michael Kerrisk <mtk.manpages@gmail.com>,
Thomas Gleixner <tglx@linutronix.de>,
<wanghaibin.wang@huawei.com>, <yezengruan@huawei.com>,
<yuzenghui@huawei.com>
Subject: Re: [RFC PATCH v4 5/9] KVM: selftests: Add a helper to get system configured THP page size
Date: Mon, 22 Mar 2021 14:42:41 +0800 [thread overview]
Message-ID: <46362177-c514-96fe-6117-4ab9716ee01d@huawei.com> (raw)
In-Reply-To: <20210312113112.laarzqhkslroagha@kamzik.brq.redhat.com>
Hi Drew,
Thanks for your attention to this series!
On 2021/3/12 19:31, Andrew Jones wrote:
> On Tue, Mar 02, 2021 at 08:57:47PM +0800, Yanan Wang 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);
> TEST_ASSERT will already output errno's string. Is that not sufficient? If
> not, I think extending TEST_ASSERT to output errno too would be fine.
I think it's a good idea to output the errno together with it's string
in TEST_ASSERT,
it will explicitly indicate that the string is an error information and
the errno is much
easier to be used for debugging than the string. I will make this change
a separate
patch in next version and add your S-b tag.
>> +
>> + 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);
> Same comment as above.
>
>> +
>> + 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);
> fscanf with %lld?
This makes senses. But it should be %ld corresponding to size_t.
Thanks,
Yanan.
>> + return size;
>> +}
>> +
>> void backing_src_help(void)
>> {
>> int i;
>> --
>> 2.23.0
>>
> Thanks,
> drew
>
> .
next prev parent reply other threads:[~2021-03-22 6:43 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-02 12:57 [RFC PATCH v4 0/9] KVM: selftests: some improvement and a new test for kvm page table Yanan Wang
2021-03-02 12:57 ` [RFC PATCH v4 1/9] tools headers: sync headers of asm-generic/hugetlb_encode.h Yanan Wang
2021-03-02 12:57 ` [RFC PATCH v4 2/9] tools headers: Add a macro to get HUGETLB page sizes for mmap Yanan Wang
2021-03-12 11:14 ` Andrew Jones
2021-03-15 2:06 ` wangyanan (Y)
2021-03-02 12:57 ` [RFC PATCH v4 3/9] KVM: selftests: Use flag CLOCK_MONOTONIC_RAW for timing Yanan Wang
2021-03-12 11:17 ` Andrew Jones
2021-03-02 12:57 ` [RFC PATCH v4 4/9] KVM: selftests: Make a generic helper to get vm guest mode strings Yanan Wang
2021-03-02 12:57 ` [RFC PATCH v4 5/9] KVM: selftests: Add a helper to get system configured THP page size Yanan Wang
2021-03-12 11:31 ` Andrew Jones
2021-03-22 6:42 ` wangyanan (Y) [this message]
2021-03-02 12:57 ` [RFC PATCH v4 6/9] KVM: selftests: Add a helper to get system default hugetlb " Yanan Wang
2021-03-12 11:40 ` Andrew Jones
2021-03-22 6:45 ` wangyanan (Y)
2021-03-02 12:57 ` [RFC PATCH v4 7/9] KVM: selftests: List all hugetlb src types specified with page sizes Yanan Wang
2021-03-12 11:49 ` Andrew Jones
2021-03-22 7:22 ` wangyanan (Y)
2021-03-12 12:02 ` Andrew Jones
2021-03-22 7:23 ` wangyanan (Y)
2021-03-02 12:57 ` [RFC PATCH v4 8/9] KVM: selftests: Adapt vm_userspace_mem_region_add to new helpers Yanan Wang
2021-03-12 11:52 ` Andrew Jones
2021-03-02 12:57 ` [RFC PATCH v4 9/9] KVM: selftests: Add a test for kvm page table code Yanan Wang
2021-03-12 14:20 ` Andrew Jones
2021-03-22 11:59 ` wangyanan (Y)
2021-03-12 5:03 ` [RFC PATCH v4 0/9] KVM: selftests: some improvement and a new test for kvm page table wangyanan (Y)
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