C-EDF: move /proc/litmus/cluster_cache to /proc/litmus/plugins/C-EDF/cluster

Make use of the new per-plugin proc file infrastructure to avoid
littering the global namespace. While at it, also move all the
relevant bits to sched_cedf.c. In the future, each plugin's parameters
should be handled in the respective plugin file.

1 files changed, 98 insertions, 9 deletions

diff --git a/litmus/sched_cedf.c b/litmus/sched_cedf.c
index f5b77080cc4f..a729d97535e9 100644
--- a/litmus/sched_cedf.c
+++ b/litmus/sched_cedf.c
@@ -30,6 +30,8 @@
 #include <linux/sched.h>
 #include <linux/slab.h>
 
+#include <linux/module.h>
+
 #include <litmus/litmus.h>
 #include <litmus/jobs.h>
 #include <litmus/sched_plugin.h>
@@ -38,7 +40,16 @@
 
 #include <litmus/bheap.h>
 
-#include <linux/module.h>
+/* to configure the cluster size */
+#include <litmus/litmus_proc.h>
+#include <linux/uaccess.h>
+
+/*
+ * It makes sense only to cluster around L2 or L3, so if cluster_index = 2
+ * (default) we cluster all the CPUs that shares a L2 cache, while
+ * cluster_cache_index = 3 we cluster all CPs that shares a L3 cache
+ */
+int cluster_index = 2;
 
 /* forward declaration... a funny thing with C ;) */
 struct clusterdomain;
@@ -641,25 +652,25 @@ static long cedf_activate_plugin(void)
         cleanup_cedf();
 
         printk(KERN_INFO "C-EDF: Activate Plugin, cache index = %d\n",
-                        cluster_cache_index);
+                        cluster_index);
 
         /* need to get cluster_size first */
         if(!zalloc_cpumask_var(&mask, GFP_ATOMIC))
                 return -ENOMEM;
 
-        if (unlikely(cluster_cache_index == num_online_cpus())) {
+        if (unlikely(cluster_index == num_online_cpus())) {
 
                 cluster_size = num_online_cpus();
         } else {
 
-                chk = get_shared_cpu_map(mask, 0, cluster_cache_index);
+                chk = get_shared_cpu_map(mask, 0, cluster_index);
                 if (chk) {
                         /* if chk != 0 then it is the max allowed index */
                         printk(KERN_INFO "C-EDF: Cannot support cache index = %d\n",
-                                        cluster_cache_index);
+                                        cluster_index);
                         printk(KERN_INFO "C-EDF: Using cache index = %d\n",
                                         chk);
-                        cluster_cache_index = chk;
+                        cluster_index = chk;
                 }
 
                 cluster_size = cpumask_weight(mask);
@@ -706,10 +717,10 @@ static long cedf_activate_plugin(void)
 
                         /* this cpu isn't in any cluster */
                         /* get the shared cpus */
-                        if (unlikely(cluster_cache_index == num_online_cpus()))
+                        if (unlikely(cluster_index == num_online_cpus()))
                                 cpumask_copy(mask, cpu_online_mask);
                         else
-                                get_shared_cpu_map(mask, cpu, cluster_cache_index);
+                                get_shared_cpu_map(mask, cpu, cluster_index);
 
                         cpumask_copy(cedf[i].cpu_map, mask);
 #ifdef VERBOSE_INIT
@@ -759,14 +770,92 @@ static struct sched_plugin cedf_plugin __cacheline_aligned_in_smp = {
 };
 
 
+/* proc file interface to configure the cluster size */
+
+static int proc_read_cluster_size(char *page, char **start,
+                                  off_t off, int count,
+                                  int *eof, void *data)
+{
+        int len;
+        if (cluster_index >= 1 && cluster_index <= 3)
+                len = snprintf(page, PAGE_SIZE, "L%d\n", cluster_index);
+        else
+                len = snprintf(page, PAGE_SIZE, "ALL\n");
+
+        return len;
+}
+
+static int proc_write_cluster_size(struct file *file,
+                                   const char *buffer,
+                                   unsigned long count,
+                                   void *data)
+{
+        int len;
+        /* L2, L3 */
+        char cache_name[33];
+
+        if(count > 32)
+                len = 32;
+        else
+                len = count;
+
+        if(copy_from_user(cache_name, buffer, len))
+                return -EFAULT;
+
+        cache_name[len] = '\0';
+        /* chomp name */
+        if (len > 1 && cache_name[len - 1] == '\n')
+                cache_name[len - 1] = '\0';
+
+        /* do a quick and dirty comparison to find the cluster size */
+        if (!strcmp(cache_name, "L2"))
+                cluster_index = 2;
+        else if (!strcmp(cache_name, "L3"))
+                cluster_index = 3;
+        else if (!strcmp(cache_name, "L1"))
+                cluster_index = 1;
+        else if (!strcmp(cache_name, "ALL"))
+                cluster_index = num_online_cpus();
+        else
+                printk(KERN_INFO "Cluster '%s' is unknown.\n", cache_name);
+
+        return len;
+}
+
+
+static struct proc_dir_entry *cluster_file = NULL, *cedf_dir = NULL;
+
+
 static int __init init_cedf(void)
 {
-        return register_sched_plugin(&cedf_plugin);
+        int err, fs;
+
+        err = register_sched_plugin(&cedf_plugin);
+        if (!err) {
+                fs = make_plugin_proc_dir(&cedf_plugin, &cedf_dir);
+                if (!fs) {
+                        cluster_file = create_proc_entry("cluster", 0644, cedf_dir);
+                        if (!cluster_file) {
+                                printk(KERN_ERR "Could not allocate C-EDF/cluster "
+                                       "procfs entry.\n");
+                        } else {
+                                cluster_file->read_proc = proc_read_cluster_size;
+                                cluster_file->write_proc = proc_write_cluster_size;
+                        }
+                } else {
+                        printk(KERN_ERR "Could not allocate C-EDF procfs dir.\n");
+                }
+        }
+        return err;
 }
 
 static void clean_cedf(void)
 {
         cleanup_cedf();
+        if (cluster_file)
+                remove_proc_entry("cluster", cedf_dir);
+        if (cedf_dir)
+                remove_plugin_proc_dir(&cedf_plugin);
 }
 
 module_init(init_cedf);