From d42f467a923dfc09309acb7a83b42e3285fbd8f4 Mon Sep 17 00:00:00 2001 Message-Id: From: Sandipan Das Date: Thu, 15 Aug 2019 13:08:28 +0530 Subject: [RHEL7 PATCH 01/31] tests: Add utility to check for a minimum number of online cpus This adds a test utility to check if a minimum number (N) of online cpus are available. If available, this will also provide a list of the first N online cpus. Signed-off-by: Sandipan Das Signed-off-by: Eric B Munson Signed-off-by: Rafael Aquini --- tests/hugetests.h | 1 + tests/testutils.c | 48 ++++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 49 insertions(+) diff --git a/tests/hugetests.h b/tests/hugetests.h index 8b1d8d9..e3179e6 100644 --- a/tests/hugetests.h +++ b/tests/hugetests.h @@ -43,6 +43,7 @@ extern char *test_name; void check_free_huge_pages(int nr_pages_needed); void check_must_be_root(void); void check_hugetlb_shm_group(void); +void check_online_cpus(int[], int); void test_init(int argc, char *argv[]); int test_addr_huge(void *p); unsigned long long get_mapping_page_size(void *p); diff --git a/tests/testutils.c b/tests/testutils.c index 6298370..2b47547 100644 --- a/tests/testutils.c +++ b/tests/testutils.c @@ -33,6 +33,8 @@ #include #include #include +#include +#include #include #include @@ -80,6 +82,52 @@ void check_hugetlb_shm_group(void) CONFIG("Do not have permission to use SHM_HUGETLB"); } +#define SYSFS_CPU_ONLINE_FMT "/sys/devices/system/cpu/cpu%d/online" + +void check_online_cpus(int online_cpus[], int nr_cpus_needed) +{ + char cpu_state, path_buf[64]; + int total_cpus, cpu_idx, fd, ret, i; + + total_cpus = get_nprocs_conf(); + cpu_idx = 0; + + if (get_nprocs() < nr_cpus_needed) + CONFIG("Atleast online %d cpus are required", nr_cpus_needed); + + for (i = 0; i < total_cpus && cpu_idx < nr_cpus_needed; i++) { + errno = 0; + sprintf(path_buf, SYSFS_CPU_ONLINE_FMT, i); + fd = open(path_buf, O_RDONLY); + if (fd < 0) { + /* If 'online' is absent, the cpu cannot be offlined */ + if (errno == ENOENT) { + online_cpus[cpu_idx] = i; + cpu_idx++; + continue; + } else { + FAIL("Unable to open %s: %s", path_buf, + strerror(errno)); + } + } + + ret = read(fd, &cpu_state, 1); + if (ret < 1) + FAIL("Unable to read %s: %s", path_buf, + strerror(errno)); + + if (cpu_state == '1') { + online_cpus[cpu_idx] = i; + cpu_idx++; + } + + close(fd); + } + + if (cpu_idx < nr_cpus_needed) + CONFIG("Atleast %d online cpus were not found", nr_cpus_needed); +} + void __attribute__((weak)) cleanup(void) { } -- 1.8.3.1