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