diff mbox series

[RFC,v4,6/9] KVM: selftests: Add a helper to get system default hugetlb page size

Message ID 20210302125751.19080-7-wangyanan55@huawei.com
State Superseded
Headers show
Series KVM: selftests: some improvement and a new test for kvm page table | expand

Commit Message

Yanan Wang March 2, 2021, 12:57 p.m. UTC
If HUGETLB is configured in the host kernel, then we can know the system
default hugetlb page size through *cat /proc/meminfo*. Otherwise, we will
not see the information of hugetlb pages in file /proc/meminfo if it's not
configured. So add a helper to determine whether HUGETLB is configured and
then get the default page size by reading /proc/meminfo.

This helper can be useful when a program wants to use the default hugetlb
pages of the system and doesn't know the default page size.

Signed-off-by: Yanan Wang <wangyanan55@huawei.com>
---
 .../testing/selftests/kvm/include/test_util.h |  1 +
 tools/testing/selftests/kvm/lib/test_util.c   | 27 +++++++++++++++++++
 2 files changed, 28 insertions(+)

Comments

Andrew Jones March 12, 2021, 11:40 a.m. UTC | #1
On Tue, Mar 02, 2021 at 08:57:48PM +0800, Yanan Wang wrote:
> If HUGETLB is configured in the host kernel, then we can know the system

> default hugetlb page size through *cat /proc/meminfo*. Otherwise, we will

> not see the information of hugetlb pages in file /proc/meminfo if it's not

> configured. So add a helper to determine whether HUGETLB is configured and

> then get the default page size by reading /proc/meminfo.

> 

> This helper can be useful when a program wants to use the default hugetlb

> pages of the system and doesn't know the default page size.

> 

> Signed-off-by: Yanan Wang <wangyanan55@huawei.com>

> ---

>  .../testing/selftests/kvm/include/test_util.h |  1 +

>  tools/testing/selftests/kvm/lib/test_util.c   | 27 +++++++++++++++++++

>  2 files changed, 28 insertions(+)

> 

> diff --git a/tools/testing/selftests/kvm/include/test_util.h b/tools/testing/selftests/kvm/include/test_util.h

> index ef24c76ba89a..e087174eefe5 100644

> --- a/tools/testing/selftests/kvm/include/test_util.h

> +++ b/tools/testing/selftests/kvm/include/test_util.h

> @@ -80,6 +80,7 @@ struct vm_mem_backing_src_alias {

>  

>  bool thp_configured(void);

>  size_t get_trans_hugepagesz(void);

> +size_t get_def_hugetlb_pagesz(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 f2d133f76c67..80d68dbd72d2 100644

> --- a/tools/testing/selftests/kvm/lib/test_util.c

> +++ b/tools/testing/selftests/kvm/lib/test_util.c

> @@ -153,6 +153,33 @@ size_t get_trans_hugepagesz(void)

>  	return size;

>  }

>  

> +size_t get_def_hugetlb_pagesz(void)

> +{

> +	char buf[64];

> +	const char *tag = "Hugepagesize:";

> +	FILE *f;

> +

> +	f = fopen("/proc/meminfo", "r");

> +	TEST_ASSERT(f != NULL, "Error in opening /proc/meminfo: %d", errno);

> +

> +	while (fgets(buf, sizeof(buf), f) != NULL) {

> +		if (strstr(buf, tag) == buf) {

> +			fclose(f);

> +			return strtoull(buf + strlen(tag), NULL, 10) << 10;

> +		}

> +	}

> +

> +	if (feof(f)) {

> +		fclose(f);

> +		TEST_FAIL("HUGETLB is not configured in host kernel");

> +	} else {

> +		fclose(f);

> +		TEST_FAIL("Error in reading /proc/meminfo: %d", errno);

> +	}


fclose() can be factored out.

> +

> +	return 0;

> +}

> +

>  void backing_src_help(void)

>  {

>  	int i;

> -- 

> 2.23.0

>


Besides the fclose comment and the same errno comment as the previous
patch

Reviewed-by: Andrew Jones <drjones@redhat.com>
Yanan Wang March 22, 2021, 6:45 a.m. UTC | #2
On 2021/3/12 19:40, Andrew Jones wrote:
> On Tue, Mar 02, 2021 at 08:57:48PM +0800, Yanan Wang wrote:

>> If HUGETLB is configured in the host kernel, then we can know the system

>> default hugetlb page size through *cat /proc/meminfo*. Otherwise, we will

>> not see the information of hugetlb pages in file /proc/meminfo if it's not

>> configured. So add a helper to determine whether HUGETLB is configured and

>> then get the default page size by reading /proc/meminfo.

>>

>> This helper can be useful when a program wants to use the default hugetlb

>> pages of the system and doesn't know the default page size.

>>

>> Signed-off-by: Yanan Wang <wangyanan55@huawei.com>

>> ---

>>   .../testing/selftests/kvm/include/test_util.h |  1 +

>>   tools/testing/selftests/kvm/lib/test_util.c   | 27 +++++++++++++++++++

>>   2 files changed, 28 insertions(+)

>>

>> diff --git a/tools/testing/selftests/kvm/include/test_util.h b/tools/testing/selftests/kvm/include/test_util.h

>> index ef24c76ba89a..e087174eefe5 100644

>> --- a/tools/testing/selftests/kvm/include/test_util.h

>> +++ b/tools/testing/selftests/kvm/include/test_util.h

>> @@ -80,6 +80,7 @@ struct vm_mem_backing_src_alias {

>>   

>>   bool thp_configured(void);

>>   size_t get_trans_hugepagesz(void);

>> +size_t get_def_hugetlb_pagesz(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 f2d133f76c67..80d68dbd72d2 100644

>> --- a/tools/testing/selftests/kvm/lib/test_util.c

>> +++ b/tools/testing/selftests/kvm/lib/test_util.c

>> @@ -153,6 +153,33 @@ size_t get_trans_hugepagesz(void)

>>   	return size;

>>   }

>>   

>> +size_t get_def_hugetlb_pagesz(void)

>> +{

>> +	char buf[64];

>> +	const char *tag = "Hugepagesize:";

>> +	FILE *f;

>> +

>> +	f = fopen("/proc/meminfo", "r");

>> +	TEST_ASSERT(f != NULL, "Error in opening /proc/meminfo: %d", errno);

>> +

>> +	while (fgets(buf, sizeof(buf), f) != NULL) {

>> +		if (strstr(buf, tag) == buf) {

>> +			fclose(f);

>> +			return strtoull(buf + strlen(tag), NULL, 10) << 10;

>> +		}

>> +	}

>> +

>> +	if (feof(f)) {

>> +		fclose(f);

>> +		TEST_FAIL("HUGETLB is not configured in host kernel");

>> +	} else {

>> +		fclose(f);

>> +		TEST_FAIL("Error in reading /proc/meminfo: %d", errno);

>> +	}

> fclose() can be factored out.

>

>> +

>> +	return 0;

>> +}

>> +

>>   void backing_src_help(void)

>>   {

>>   	int i;

>> -- 

>> 2.23.0

>>

> Besides the fclose comment and the same errno comment as the previous

> patch

I will fix it and add your R-b in this patch.

Thanks,
Yanan
> Reviewed-by: Andrew Jones <drjones@redhat.com>

>

> .
diff mbox series

Patch

diff --git a/tools/testing/selftests/kvm/include/test_util.h b/tools/testing/selftests/kvm/include/test_util.h
index ef24c76ba89a..e087174eefe5 100644
--- a/tools/testing/selftests/kvm/include/test_util.h
+++ b/tools/testing/selftests/kvm/include/test_util.h
@@ -80,6 +80,7 @@  struct vm_mem_backing_src_alias {
 
 bool thp_configured(void);
 size_t get_trans_hugepagesz(void);
+size_t get_def_hugetlb_pagesz(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 f2d133f76c67..80d68dbd72d2 100644
--- a/tools/testing/selftests/kvm/lib/test_util.c
+++ b/tools/testing/selftests/kvm/lib/test_util.c
@@ -153,6 +153,33 @@  size_t get_trans_hugepagesz(void)
 	return size;
 }
 
+size_t get_def_hugetlb_pagesz(void)
+{
+	char buf[64];
+	const char *tag = "Hugepagesize:";
+	FILE *f;
+
+	f = fopen("/proc/meminfo", "r");
+	TEST_ASSERT(f != NULL, "Error in opening /proc/meminfo: %d", errno);
+
+	while (fgets(buf, sizeof(buf), f) != NULL) {
+		if (strstr(buf, tag) == buf) {
+			fclose(f);
+			return strtoull(buf + strlen(tag), NULL, 10) << 10;
+		}
+	}
+
+	if (feof(f)) {
+		fclose(f);
+		TEST_FAIL("HUGETLB is not configured in host kernel");
+	} else {
+		fclose(f);
+		TEST_FAIL("Error in reading /proc/meminfo: %d", errno);
+	}
+
+	return 0;
+}
+
 void backing_src_help(void)
 {
 	int i;