Use num_online_gpus()

Note that num_online_gpus() merely reports the
staticly configured maximum number of available
GPUs.  Will make dynamic in the future.

1 files changed, 19 insertions, 8 deletions

diff --git a/litmus/sched_cedf.c b/litmus/sched_cedf.c
index 35ea1544ce69..46de8041cf59 100644
--- a/litmus/sched_cedf.c
+++ b/litmus/sched_cedf.c
@@ -157,6 +157,13 @@ static unsigned int cluster_size;
 
 static int clusters_allocated = 0;
 
+
+#if defined(CONFIG_LITMUS_NVIDIA) && defined(CONFIG_LITMUS_SOFTIRQD)
+static int num_gpu_clusters;
+static unsigned int gpu_cluster_size;
+#endif
+
+
 #ifdef CONFIG_LITMUS_DGL_SUPPORT
 static raw_spinlock_t* cedf_get_dgl_spinlock(struct task_struct *t)
 {
@@ -1653,18 +1660,11 @@ static void cleanup_cedf(void)
 }
 
 #if defined(CONFIG_LITMUS_NVIDIA) && defined(CONFIG_LITMUS_SOFTIRQD)
-static int cedf_map_gpu_to_cpu(int gpu, int num_gpus)
+static int cedf_map_gpu_to_cpu(int gpu)
 {
-        /* TODO: Some sort of smart clustering on the PCIe bus topology */
-        int num_gpu_clusters = num_clusters;
-        unsigned int gpu_cluster_size = num_gpus / num_gpu_clusters;
         int cpu_cluster = gpu / gpu_cluster_size;
         int default_cpu = cedf[cpu_cluster].cpus[0]->cpu;  // first CPU in given cluster
 
-        if(num_gpus % num_gpu_clusters != 0) {
-                TRACE("GPU clusters are of non-uniform size!\n");
-        }
-
         TRACE("CPU %d is default for GPU %d interrupt threads.\n", default_cpu, gpu);
 
         return default_cpu;
@@ -1717,6 +1717,17 @@ static long cedf_activate_plugin(void)
         printk(KERN_INFO "C-EDF: %d cluster(s) of size = %d\n",
                         num_clusters, cluster_size);
 
+        
+#if defined(CONFIG_LITMUS_NVIDIA) && defined(CONFIG_LITMUS_SOFTIRQD)
+        num_gpu_clusters = min(num_clusters, num_online_gpus());
+        gpu_cluster_size = num_online_gpus() / num_gpu_clusters;
+        
+        if (((num_online_gpus() % gpu_cluster_size) != 0) ||
+                (num_gpu_clusters != num_clusters)) {
+                printk(KERN_WARNING "C-EDF: GPUs not uniformly distributed among CPU clusters.\n");
+        }
+#endif
+        
         /* initialize clusters */
         cedf = kmalloc(num_clusters * sizeof(cedf_domain_t), GFP_ATOMIC);
         for (i = 0; i < num_clusters; i++) {