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

2021-03-22 Thread wangyanan (Y) 



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 
---
  .../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 

.

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

2021-03-12 Thread Andrew Jones 
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 
> ---
>  .../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

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

2021-03-02 Thread Yanan Wang 
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 
---
 .../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);
+   }
+
+   return 0;
+}
+
 void backing_src_help(void)
 {
int i;
-- 
2.23.0