CPU view: handle CPU hotplug at runtime

[mirror_lxcfs.git] / bindings.c

diff --git a/bindings.c b/bindings.c
index 204e738048701b67b412ca8aed5c785c5f109267..e838441c01213255c479057c1a5b2c7f1b2ac829 100644 (file)
--- a/bindings.c
+++ b/bindings.c
@@ -4341,6 +4341,53 @@ out:
        return rv;
 }
 
+static bool expand_proc_stat_node(struct cg_proc_stat *node, int cpu_count)
+{
+       struct cpuacct_usage *new_usage, *new_view;
+       int i;
+
+       /* Allocate new memory */
+       new_usage = malloc(sizeof(struct cpuacct_usage) * cpu_count);
+       if (!new_usage)
+               return false;
+
+       new_view = malloc(sizeof(struct cpuacct_usage) * cpu_count);
+       if (!new_view) {
+               free(new_usage);
+               return false;
+       }
+
+       /* Copy existing data & initialize new elements */
+       for (i = 0; i < cpu_count; i++) {
+               if (i < node->cpu_count) {
+                       new_usage[i].user = node->usage[i].user;
+                       new_usage[i].system = node->usage[i].system;
+                       new_usage[i].idle = node->usage[i].idle;
+
+                       new_view[i].user = node->view[i].user;
+                       new_view[i].system = node->view[i].system;
+                       new_view[i].idle = node->view[i].idle;
+               } else {
+                       new_usage[i].user = 0;
+                       new_usage[i].system = 0;
+                       new_usage[i].idle = 0;
+
+                       new_view[i].user = 0;
+                       new_view[i].system = 0;
+                       new_view[i].idle = 0;
+               }
+       }
+
+       free(node->usage);
+       free(node->view);
+
+       node->usage = new_usage;
+       node->view = new_view;
+       node->cpu_count = cpu_count;
+
+       return true;
+}
+
 static struct cg_proc_stat *find_or_create_proc_stat_node(struct cpuacct_usage *usage, int cpu_count, const char *cg)
 {
        int hash = calc_hash(cg) % CPUVIEW_HASH_SIZE;
@@ -4359,6 +4406,21 @@ static struct cg_proc_stat *find_or_create_proc_stat_node(struct cpuacct_usage *
        }
 
        pthread_mutex_lock(&node->lock);
+
+       /* If additional CPUs on the host have been enabled, CPU usage counter
+        * arrays have to be expanded */
+       if (node->cpu_count < cpu_count) {
+               lxcfs_debug("Expanding stat node %d->%d for %s\n",
+                               node->cpu_count, cpu_count, cg);
+
+               if (!expand_proc_stat_node(node, cpu_count)) {
+                       pthread_mutex_unlock(&node->lock);
+                       lxcfs_debug("Unable to expand stat node %d->%d for %s\n",
+                                       node->cpu_count, cpu_count, cg);
+                       return NULL;
+               }
+       }
+
        return node;
 }