From fb0f6ca9385e1813311cfd917c130b40bec04970 Mon Sep 17 00:00:00 2001 From: Michael Jeanson Date: Thu, 28 Jul 2022 10:17:48 -0400 Subject: [PATCH] Add more unit tests for possible_cpus_array_len Change-Id: If0b7fb9183936f00ac90349fb32f1db57f124602 Signed-off-by: Michael Jeanson Signed-off-by: Mathieu Desnoyers --- .gitignore | 5 +- src/common/smp.c | 76 ++++++++++++---- src/common/smp.h | 27 ++++++ tests/Makefile.am | 5 +- tests/unit/libcommon/Makefile.am | 28 +++++- .../unit/libcommon/get_cpu_mask_from_sysfs.c | 30 +++++++ .../unit/libcommon/get_max_cpuid_from_sysfs.c | 29 ++++++ .../libcommon/test_get_cpu_mask_from_sysfs | 51 +++++++++++ ...t_smp.c => test_get_max_cpuid_from_mask.c} | 11 +-- .../libcommon/test_get_max_cpuid_from_sysfs | 89 +++++++++++++++++++ .../test_get_possible_cpus_array_len.c | 26 ++++++ 11 files changed, 344 insertions(+), 33 deletions(-) create mode 100644 tests/unit/libcommon/get_cpu_mask_from_sysfs.c create mode 100644 tests/unit/libcommon/get_max_cpuid_from_sysfs.c create mode 100755 tests/unit/libcommon/test_get_cpu_mask_from_sysfs rename tests/unit/libcommon/{test_smp.c => test_get_max_cpuid_from_mask.c} (81%) create mode 100755 tests/unit/libcommon/test_get_max_cpuid_from_sysfs create mode 100644 tests/unit/libcommon/test_get_possible_cpus_array_len.c diff --git a/.gitignore b/.gitignore index bde22085..6cc8fb24 100644 --- a/.gitignore +++ b/.gitignore @@ -113,7 +113,10 @@ cscope.* /tests/regression/abi0-conflict/app_ust_indirect_abi0_abi1 /tests/regression/abi0-conflict/app_ust_indirect_abi1 /tests/unit/gcc-weak-hidden/test_gcc_weak_hidden -/tests/unit/libcommon/test_smp +/tests/unit/libcommon/get_cpu_mask_from_sysfs +/tests/unit/libcommon/get_max_cpuid_from_sysfs +/tests/unit/libcommon/test_get_max_cpuid_from_mask +/tests/unit/libcommon/test_get_possible_cpus_array_len /tests/unit/libmsgpack/test_msgpack /tests/unit/libringbuffer/test_shm /tests/unit/pthread_name/test_pthread_name diff --git a/src/common/smp.c b/src/common/smp.c index 8bbf9f6f..8c742028 100644 --- a/src/common/smp.c +++ b/src/common/smp.c @@ -28,33 +28,29 @@ static int possible_cpus_array_len_cache; /* - * As a fallback to parsing the CPU mask in "/sys/devices/system/cpu/possible", - * iterate on all the folders in "/sys/devices/system/cpu" that start with + * Get the highest CPU id from sysfs. + * + * Iterate on all the folders in "/sys/devices/system/cpu" that start with * "cpu" followed by an integer, keep the highest CPU id encountered during * this iteration and add 1 to get a number of CPUs. * - * Then get the value from sysconf(_SC_NPROCESSORS_CONF) as a fallback and - * return the highest one. - * - * On Linux, using the value from sysconf can be unreliable since the way it - * counts CPUs varies between C libraries and even between versions of the same - * library. If we used it directly, getcpu() could return a value greater than - * this sysconf, in which case the arrays indexed by processor would overflow. - * - * As another example, the MUSL libc implementation of the _SC_NPROCESSORS_CONF - * sysconf does not return the number of configured CPUs in the system but - * relies on the cpu affinity mask of the current task. - * - * Returns 0 or less on error. + * Returns the highest CPU id, or -1 on error. */ -int get_num_possible_cpus_fallback(void) +int get_max_cpuid_from_sysfs(void) +{ + return _get_max_cpuid_from_sysfs("/sys/devices/system/cpu"); +} + +int _get_max_cpuid_from_sysfs(const char *path) { long max_cpuid = -1; DIR *cpudir; struct dirent *entry; - cpudir = opendir("/sys/devices/system/cpu"); + assert(path); + + cpudir = opendir(path); if (cpudir == NULL) goto end; @@ -85,10 +81,35 @@ int get_num_possible_cpus_fallback(void) max_cpuid = -1; end: + return max_cpuid; +} + +/* + * As a fallback to parsing the CPU mask in "/sys/devices/system/cpu/possible", + * iterate on all the folders in "/sys/devices/system/cpu" that start with + * "cpu" followed by an integer, keep the highest CPU id encountered during + * this iteration and add 1 to get a number of CPUs. + * + * Then get the value from sysconf(_SC_NPROCESSORS_CONF) as a fallback and + * return the highest one. + * + * On Linux, using the value from sysconf can be unreliable since the way it + * counts CPUs varies between C libraries and even between versions of the same + * library. If we used it directly, getcpu() could return a value greater than + * this sysconf, in which case the arrays indexed by processor would overflow. + * + * As another example, the MUSL libc implementation of the _SC_NPROCESSORS_CONF + * sysconf does not return the number of configured CPUs in the system but + * relies on the cpu affinity mask of the current task. + * + * Returns 0 or less on error. + */ +int get_num_possible_cpus_fallback(void) +{ /* * Get the sysconf value as a last resort. Keep the highest number. */ - return __max(sysconf(_SC_NPROCESSORS_CONF), max_cpuid + 1); + return __max(sysconf(_SC_NPROCESSORS_CONF), get_max_cpuid_from_sysfs() + 1); } /* @@ -100,15 +121,32 @@ end: * Returns the number of bytes read or -1 on error. */ int get_possible_cpu_mask_from_sysfs(char *buf, size_t max_bytes) +{ + return get_cpu_mask_from_sysfs(buf, max_bytes, + "/sys/devices/system/cpu/possible"); +} + +/* + * Get a CPU mask string from sysfs. + * + * buf: the buffer where the mask will be read. + * max_bytes: the maximum number of bytes to write in the buffer. + * path: file path to read the mask from. + * + * Returns the number of bytes read or -1 on error. + */ +int get_cpu_mask_from_sysfs(char *buf, size_t max_bytes, const char *path) { ssize_t bytes_read = 0; size_t total_bytes_read = 0; int fd = -1, ret = -1; + assert(path); + if (buf == NULL) goto end; - fd = open("/sys/devices/system/cpu/possible", O_RDONLY); + fd = open(path, O_RDONLY); if (fd < 0) goto end; diff --git a/src/common/smp.h b/src/common/smp.h index f908b6c6..0a8433f3 100644 --- a/src/common/smp.h +++ b/src/common/smp.h @@ -9,6 +9,18 @@ #define LTTNG_UST_CPUMASK_SIZE 4096 +/* + * Get a CPU mask string from sysfs. + * + * buf: the buffer where the mask will be read. + * max_bytes: the maximum number of bytes to write in the buffer. + * path: file path to read the mask from. + * + * Returns the number of bytes read or -1 on error. + */ +int get_cpu_mask_from_sysfs(char *buf, size_t max_bytes, const char *path) + __attribute__((visibility("hidden"))); + /* * Get the CPU possible mask string from sysfs. * @@ -20,6 +32,21 @@ int get_possible_cpu_mask_from_sysfs(char *buf, size_t max_bytes) __attribute__((visibility("hidden"))); +/* + * Get the highest CPU id from sysfs. + * + * Iterate on all the folders in "/sys/devices/system/cpu" that start with + * "cpu" followed by an integer, keep the highest CPU id encountered during + * this iteration and add 1 to get a number of CPUs. + * + * Returns the highest CPU id, or -1 on error. + */ +int get_max_cpuid_from_sysfs(void) + __attribute__((visibility("hidden"))); + +int _get_max_cpuid_from_sysfs(const char *path) + __attribute__((visibility("hidden"))); + /* * Get the number of possible CPUs in the system from either * sysconf(_SC_NPROCESSORS_CONF) or some other mechanism depending on the libc. diff --git a/tests/Makefile.am b/tests/Makefile.am index 29cfa814..ac4d1cc9 100644 --- a/tests/Makefile.am +++ b/tests/Makefile.am @@ -13,7 +13,10 @@ LOG_DRIVER = env AM_TAP_AWK='$(AWK)' \ TESTS = \ unit/libringbuffer/test_shm \ unit/gcc-weak-hidden/test_gcc_weak_hidden \ - unit/libcommon/test_smp \ + unit/libcommon/test_get_cpu_mask_from_sysfs \ + unit/libcommon/test_get_max_cpuid_from_mask \ + unit/libcommon/test_get_max_cpuid_from_sysfs \ + unit/libcommon/test_get_possible_cpus_array_len \ unit/libmsgpack/test_msgpack \ unit/pthread_name/test_pthread_name \ unit/snprintf/test_snprintf \ diff --git a/tests/unit/libcommon/Makefile.am b/tests/unit/libcommon/Makefile.am index 05b894e8..77f3b852 100644 --- a/tests/unit/libcommon/Makefile.am +++ b/tests/unit/libcommon/Makefile.am @@ -2,8 +2,30 @@ AM_CPPFLAGS += -I$(top_srcdir)/tests/utils -noinst_PROGRAMS = test_smp -test_smp_SOURCES = test_smp.c -test_smp_LDADD = \ +noinst_PROGRAMS = \ + get_cpu_mask_from_sysfs \ + get_max_cpuid_from_sysfs \ + test_get_max_cpuid_from_mask \ + test_get_possible_cpus_array_len + +dist_noinst_SCRIPTS = \ + test_get_cpu_mask_from_sysfs \ + test_get_max_cpuid_from_sysfs + +get_cpu_mask_from_sysfs_SOURCES = get_cpu_mask_from_sysfs.c +get_cpu_mask_from_sysfs_LDADD = \ + $(top_builddir)/src/common/libcommon.la + +get_max_cpuid_from_sysfs_SOURCES = get_max_cpuid_from_sysfs.c +get_max_cpuid_from_sysfs_LDADD = \ + $(top_builddir)/src/common/libcommon.la + +test_get_max_cpuid_from_mask_SOURCES = test_get_max_cpuid_from_mask.c +test_get_max_cpuid_from_mask_LDADD = \ + $(top_builddir)/src/common/libcommon.la \ + $(top_builddir)/tests/utils/libtap.a + +test_get_possible_cpus_array_len_SOURCES = test_get_possible_cpus_array_len.c +test_get_possible_cpus_array_len_LDADD = \ $(top_builddir)/src/common/libcommon.la \ $(top_builddir)/tests/utils/libtap.a diff --git a/tests/unit/libcommon/get_cpu_mask_from_sysfs.c b/tests/unit/libcommon/get_cpu_mask_from_sysfs.c new file mode 100644 index 00000000..e4dd0397 --- /dev/null +++ b/tests/unit/libcommon/get_cpu_mask_from_sysfs.c @@ -0,0 +1,30 @@ +/* + * SPDX-License-Identifier: LGPL-2.1-only + * + * Copyright (C) 2022 Michael Jeanson + */ + +#include +#include + +#include "common/smp.h" + +int main(int argc, char *argv[]) +{ + int ret; + char buf[LTTNG_UST_CPUMASK_SIZE]; + + if( argc < 2 ) { + fprintf(stderr, "Missing argument.\n"); + return EXIT_FAILURE; + } + + ret = get_cpu_mask_from_sysfs((char *) &buf, LTTNG_UST_CPUMASK_SIZE, argv[1]); + + printf("%s", buf); + + if (ret >= 0) + return EXIT_SUCCESS; + else + return EXIT_FAILURE; +} diff --git a/tests/unit/libcommon/get_max_cpuid_from_sysfs.c b/tests/unit/libcommon/get_max_cpuid_from_sysfs.c new file mode 100644 index 00000000..cc856c6d --- /dev/null +++ b/tests/unit/libcommon/get_max_cpuid_from_sysfs.c @@ -0,0 +1,29 @@ +/* + * SPDX-License-Identifier: LGPL-2.1-only + * + * Copyright (C) 2022 Michael Jeanson + */ + +#include +#include + +#include "common/smp.h" + +int main(int argc, char *argv[]) +{ + int ret; + + if( argc < 2 ) { + fprintf(stderr, "Missing argument.\n"); + return EXIT_FAILURE; + } + + ret = _get_max_cpuid_from_sysfs(argv[1]); + + printf("%d\n", ret); + + if (ret >= 0) + return EXIT_SUCCESS; + else + return EXIT_FAILURE; +} diff --git a/tests/unit/libcommon/test_get_cpu_mask_from_sysfs b/tests/unit/libcommon/test_get_cpu_mask_from_sysfs new file mode 100755 index 00000000..528ace29 --- /dev/null +++ b/tests/unit/libcommon/test_get_cpu_mask_from_sysfs @@ -0,0 +1,51 @@ +#!/bin/bash +# SPDX-License-Identifier: LGPL-2.1-only + +if [ "x${UST_TESTS_SRCDIR:-}" != "x" ]; then + UTILSSH="$UST_TESTS_SRCDIR/utils/utils.sh" +else + UTILSSH="$(dirname "$0")/../../utils/utils.sh" +fi + +# shellcheck source=../../utils/utils.sh +source "$UTILSSH" + +# shellcheck source=../../utils/tap.sh +source "$UST_TESTS_SRCDIR/utils/tap.sh" + +CURDIR="${UST_TESTS_BUILDDIR}/unit/libcommon" + +NUM_TESTS=8 + +TESTFILE=$(mktemp) + +populate_testfile() { + local cpumask="$1" + + # shellcheck disable=SC2059 + printf "$cpumask" > "$TESTFILE" +} + +test_test_get_cpu_mask_from_sysfs() { + local cpumask="$1" + local result + + # Without '\n' + populate_testfile "$cpumask" + result=$("${CURDIR}/get_cpu_mask_from_sysfs" "$TESTFILE") + test "$cpumask" == "$result" + ok $? "test_get_cpu_mask_from_sysfs - without '\n' expected: '$cpumask', result: '$result'" + + # With '\n' + populate_testfile "$cpumask\n" + result=$("${CURDIR}/get_cpu_mask_from_sysfs" "$TESTFILE") + test "$cpumask" == "$result" + ok $? "test_get_cpu_mask_from_sysfs - with '\n' expected: '$cpumask', result: '$result'" +} + +plan_tests $NUM_TESTS + +test_test_get_cpu_mask_from_sysfs "" +test_test_get_cpu_mask_from_sysfs "0" +test_test_get_cpu_mask_from_sysfs "0-3" +test_test_get_cpu_mask_from_sysfs "0,3-7,9" diff --git a/tests/unit/libcommon/test_smp.c b/tests/unit/libcommon/test_get_max_cpuid_from_mask.c similarity index 81% rename from tests/unit/libcommon/test_smp.c rename to tests/unit/libcommon/test_get_max_cpuid_from_mask.c index 7180076b..b1bd868b 100644 --- a/tests/unit/libcommon/test_smp.c +++ b/tests/unit/libcommon/test_get_max_cpuid_from_mask.c @@ -1,14 +1,9 @@ /* * SPDX-License-Identifier: LGPL-2.1-only * - * Copyright (C) 2020 Francis Deslauriers + * Copyright (C) 2022 Michael Jeanson */ -#include -#include -#include -#include -#include #include #include "tap.h" @@ -66,7 +61,7 @@ int main(void) { int ret, i; - plan_tests(parse_test_data_len + 1); + plan_tests(parse_test_data_len); diag("Testing smp helpers"); @@ -78,7 +73,5 @@ int main(void) parse_test_data[i].buf, parse_test_data[i].expected, ret); } - ok(get_possible_cpus_array_len() > 0, "get_possible_cpus_array_len (%d > 0)", get_possible_cpus_array_len()); - return exit_status(); } diff --git a/tests/unit/libcommon/test_get_max_cpuid_from_sysfs b/tests/unit/libcommon/test_get_max_cpuid_from_sysfs new file mode 100755 index 00000000..1d344bae --- /dev/null +++ b/tests/unit/libcommon/test_get_max_cpuid_from_sysfs @@ -0,0 +1,89 @@ +#!/bin/bash +# SPDX-License-Identifier: LGPL-2.1-only + +if [ "x${UST_TESTS_SRCDIR:-}" != "x" ]; then + UTILSSH="$UST_TESTS_SRCDIR/utils/utils.sh" +else + UTILSSH="$(dirname "$0")/../../utils/utils.sh" +fi + +# shellcheck source=../../utils/utils.sh +source "$UTILSSH" + +# shellcheck source=../../utils/tap.sh +source "$UST_TESTS_SRCDIR/utils/tap.sh" + +CURDIR="${UST_TESTS_BUILDDIR}/unit/libcommon" + +STD_OUTPUT="/dev/null" +STD_ERROR="/dev/null" + +NUM_TESTS=13 + +TESTDIR=$(mktemp -d) + +populate_testdir() { + local cpus=("$@") + + mkdir "$TESTDIR" + + for i in "${cpus[@]}"; do + mkdir "$TESTDIR/$i" + done +} + +test_get_max_cpuid_from_sysfs() { + local num_cpus=$1 + shift + local current_cpus=("$@") + local result + + populate_testdir "${current_cpus[@]}" >"$STD_OUTPUT" 2>"$STD_ERROR" + result=$("${CURDIR}/get_max_cpuid_from_sysfs" "$TESTDIR") + is "$result" "$num_cpus" "get_max_cpuid_from_sysfs - cpu set: '${current_cpus[*]}', expected: '$num_cpus', result: '$result'" + rm -rf "$TESTDIR" +} + +plan_tests $NUM_TESTS + +diag "get_max_cpuid_from_sysfs" + +test_data=(0 "cpu0") +test_get_max_cpuid_from_sysfs "${test_data[@]}" + +test_data=(1 "cpu0" "cpu1") +test_get_max_cpuid_from_sysfs "${test_data[@]}" + +test_data=(1 "cpu1" "cpu0") +test_get_max_cpuid_from_sysfs "${test_data[@]}" + +test_data=(3 "cpu3") +test_get_max_cpuid_from_sysfs "${test_data[@]}" + +test_data=(99 "cpu99") +test_get_max_cpuid_from_sysfs "${test_data[@]}" + +test_data=(3 "cpu0" "cpu3") +test_get_max_cpuid_from_sysfs "${test_data[@]}" + +test_data=(3 "cpufreq" "cpuidle" "cpu0" "cpu1" "cpu2" "cpu3") +test_get_max_cpuid_from_sysfs "${test_data[@]}" + +test_data=(0 "cpu" "cpu0") +test_get_max_cpuid_from_sysfs "${test_data[@]}" + +test_data=(5 "cpu" "cpu5") +test_get_max_cpuid_from_sysfs "${test_data[@]}" + + +test_data=(-1 "toto") +test_get_max_cpuid_from_sysfs "${test_data[@]}" + +test_data=(-1 "cpu") +test_get_max_cpuid_from_sysfs "${test_data[@]}" + +test_data=(-1 "cpua" "cpud") +test_get_max_cpuid_from_sysfs "${test_data[@]}" + +test_data=(-1 "cpufreq" "cpuidle") +test_get_max_cpuid_from_sysfs "${test_data[@]}" diff --git a/tests/unit/libcommon/test_get_possible_cpus_array_len.c b/tests/unit/libcommon/test_get_possible_cpus_array_len.c new file mode 100644 index 00000000..621f42af --- /dev/null +++ b/tests/unit/libcommon/test_get_possible_cpus_array_len.c @@ -0,0 +1,26 @@ +/* + * SPDX-License-Identifier: LGPL-2.1-only + * + * Copyright (C) 2022 Michael Jeanson + */ + +#include + +#include "tap.h" + +#include "common/smp.h" + +int main(void) +{ + int ret; + + plan_tests(2); + + ret = get_possible_cpus_array_len(); + ok(ret > 0, "get_possible_cpus_array_len (%d > 0)", ret); + + ret = get_num_possible_cpus_fallback(); + ok(ret > 0, "get_num_possible_cpus_fallback (%d > 0)", ret); + + return exit_status(); +} -- 2.34.1