[LibOS] Add /sys/devices/system/cpu/{offline,present} files

Also improve the `sysfs` LibOS regression test to verify that these new CPU-related files exist, plus that the old CPU- and NUMA-node-related files exist. Signed-off-by: Dmitrii Kuvaiskii <[email protected]>
gramineproject · Aug 3, 2023 · 92636ae · 92636ae
1 parent 3b5c88b
commit 92636ae
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Showing 3 changed files with 17 additions and 1 deletion.
diff --git a/libos/src/fs/sys/cpu_info.c b/libos/src/fs/sys/cpu_info.c
@@ -17,6 +17,10 @@ static bool is_online(size_t ind, const void* arg) {
     return g_pal_public_state->topo_info.threads[ind].is_online;
 }
 
+static bool is_offline(size_t ind, const void* arg) {
+    return !is_online(ind, arg);
+}
+
 static bool return_true(size_t ind, const void* arg) {
     __UNUSED(ind);
     __UNUSED(arg);
@@ -31,7 +35,11 @@ int sys_cpu_general_load(struct libos_dentry* dent, char** out_data, size_t* out
 
     if (strcmp(name, "online") == 0) {
         ret = sys_print_as_ranges(str, sizeof(str), topo->threads_cnt, is_online, NULL);
-    } else if (strcmp(name, "possible") == 0) {
+    } else if (strcmp(name, "offline") == 0) {
+        ret = sys_print_as_ranges(str, sizeof(str), topo->threads_cnt, is_offline, NULL);
+    } else if (strcmp(name, "possible") == 0 || strcmp(name, "present") == 0) {
+        /* we simplify and always output "present" CPUs same as "possible" CPUs; this will need to
+         * be changed if we add support for hot-plugging CPUs / shutting down / powering up CPUs */
         ret = sys_print_as_ranges(str, sizeof(str), topo->threads_cnt, return_true, NULL);
     } else {
         log_debug("unrecognized file: %s", name);

diff --git a/libos/src/fs/sys/fs.c b/libos/src/fs/sys/fs.c
@@ -207,7 +207,9 @@ int sys_load(const char* str, char** out_data, size_t* out_size) {
 
 static void init_cpu_dir(struct pseudo_node* cpu) {
     pseudo_add_str(cpu, "online", &sys_cpu_general_load);
+    pseudo_add_str(cpu, "offline", &sys_cpu_general_load);
     pseudo_add_str(cpu, "possible", &sys_cpu_general_load);
+    pseudo_add_str(cpu, "present", &sys_cpu_general_load);
 
     struct pseudo_node* cpuX = pseudo_add_dir(cpu, NULL);
     cpuX->name_exists = &sys_resource_name_exists;

diff --git a/libos/test/regression/test_libos.py b/libos/test/regression/test_libos.py
@@ -1142,6 +1142,10 @@ def test_040_sysfs(self):
         lines = stdout.splitlines()
 
         self.assertIn('/sys/devices/system/cpu: directory', lines)
+        self.assertIn('/sys/devices/system/cpu/online: file', lines)
+        self.assertIn('/sys/devices/system/cpu/offline: file', lines)
+        self.assertIn('/sys/devices/system/cpu/possible: file', lines)
+        self.assertIn('/sys/devices/system/cpu/present: file', lines)
         for i in range(cpus_cnt):
             cpu = f'/sys/devices/system/cpu/cpu{i}'
             self.assertIn(f'{cpu}: directory', lines)
@@ -1167,6 +1171,8 @@ def test_040_sysfs(self):
                 self.assertIn(f'{cache}/physical_line_partition: file', lines)
 
         self.assertIn('/sys/devices/system/node: directory', lines)
+        self.assertIn('/sys/devices/system/node/online: file', lines)
+        self.assertIn('/sys/devices/system/node/possible: file', lines)
         nodes_cnt = len([line for line in lines
                          if re.match(r'/sys/devices/system/node/node[0-9]+:', line)])
         self.assertGreater(nodes_cnt, 0)