cgroup: honor cpu burst

Signed-off-by: Giuseppe Scrivano <[email protected]>

src/libcrun/cgroup-internal.h

@@ -84,4 +84,6 @@ int initialize_cpuset_subsystem (const char *path, libcrun_error_t *err);
 
 int write_cpuset_resources (int dirfd_cpuset, int cgroup2, runtime_spec_schema_config_linux_resources_cpu *cpu, libcrun_error_t *err);
 
+int write_cpu_burst (int cpu_dirfd, bool cgroup2, runtime_spec_schema_config_linux_resources_cpu *cpu, libcrun_error_t *err);
+
 #endif

src/libcrun/cgroup-resources.c

@@ -888,6 +888,21 @@ write_memory_resources (int dirfd, bool cgroup2, runtime_spec_schema_config_linu
   return 0;
 }
 
+int
+write_cpu_burst (int cpu_dirfd, bool cgroup2, runtime_spec_schema_config_linux_resources_cpu *cpu,
+                 libcrun_error_t *err)
+{
+  char fmt_buf[32];
+  size_t len;
+  int ret;
+
+  if (! cpu->burst_present)
+    return 0;
+
+  len = sprintf (fmt_buf, "%" PRIi64, cpu->burst);
+  return write_cgroup_file (cpu_dirfd, cgroup2 ? "cpu.max.burst" : "cpu.cfs_burst_us", fmt_buf, len, err);
+}
+
 static int
 write_pids_resources (int dirfd, bool cgroup2, runtime_spec_schema_config_linux_resources_pids *pids,
                       libcrun_error_t *err)
@@ -1013,7 +1028,8 @@ write_cpu_resources (int dirfd_cpu, bool cgroup2, runtime_spec_schema_config_lin
       if (UNLIKELY (ret < 0))
         return ret;
     }
-  return 0;
+
+  return write_cpu_burst (dirfd_cpu, cgroup2, cpu, err);
 }
 
 int

src/libcrun/cgroup-systemd.c

@@ -198,6 +198,41 @@ setup_rt_runtime (runtime_spec_schema_config_linux_resources *resources,
   return 0;
 }
 
+static int
+setup_missing_cpu_options_for_systemd (runtime_spec_schema_config_linux_resources *resources, bool cgroup2, const char *path, libcrun_error_t *err)
+{
+  cleanup_free char *cgroup_path = NULL;
+  cleanup_close int dirfd = -1;
+  int parent;
+  int ret;
+
+  if (resources->cpu == NULL)
+    return 0;
+
+  if (! cpu->burst_present)
+    return 0;
+
+  for (parent = 0; parent < 2; parent++)
+    {
+      if (cgroup2)
+        ret = append_paths (&cgroup_path, err, CGROUP_ROOT, path ? path : "", (parent ? ".." : NULL), NULL);
+      else
+        ret = append_paths (&cgroup_path, err, CGROUP_ROOT, "/cpu", path ? path : "", (parent ? ".." : NULL), NULL);
+      if (UNLIKELY (ret < 0))
+        return ret;
+
+      dirfd = open (cgroup_path, O_DIRECTORY | O_CLOEXEC);
+      if (UNLIKELY (dirfd < 0))
+        return crun_make_error (err, errno, "open `%s`", cgroup_path);
+
+      ret = write_cpu_burst (dirfd, cgroup2, resources->cpu, err);
+      if (UNLIKELY (ret < 0))
+        return ret;
+    }
+
+  return 0;
+}
+
 static int
 setup_cpuset_for_systemd_v1 (runtime_spec_schema_config_linux_resources *resources, const char *path, libcrun_error_t *err)
 {
@@ -381,6 +416,10 @@ systemd_finalize (struct libcrun_cgroup_args *args, char **path_out,
       return crun_make_error (err, 0, "invalid cgroup mode `%d`", cgroup_mode);
     }
 
+  ret = setup_missing_cpu_options_for_systemd (resources, cgroup_mode == CGROUP_MODE_UNIFIED, path, err);
+  if (UNLIKELY (ret < 0))
+    return ret;
+
   *path_out = path;
   path = NULL;
 
@@ -1381,6 +1420,10 @@ libcrun_update_resources_systemd (struct libcrun_cgroup_status *cgroup_status,
         goto exit;
     }
 
+  ret = setup_missing_cpu_options_for_systemd (resources, cgroup_mode == CGROUP_MODE_UNIFIED, cgroup_status->path, err);
+  if (UNLIKELY (ret < 0))
+    goto exit;
+
   ret = 0;
 
 exit: