Redesign reschedule points, allow one operation to reschedule many cpus at once

kernel/proc/reschedule.c

@@ -0,0 +1,32 @@
+#include <libk/list.h>
+#include <mm/liballoc.h>
+#include <proc/reschedule.h>
+#include <sync/spin_lock.h>
+#include <sys/smp.h>
+
+void reschedule_list_append (struct reschedule_ctx* rctx, struct cpu* cpu) {
+  spin_lock (&rctx->lock);
+
+  struct list_node_link *node, *tmp;
+  list_foreach (rctx->entries, node, tmp) {
+    struct reschedule_entry* entry = list_entry (node, struct reschedule_entry, link);
+
+    if (entry->cpu == cpu) {
+      spin_unlock (&rctx->lock);
+      return;
+    }
+  }
+
+  struct reschedule_entry* entry = malloc (sizeof (*entry));
+
+  if (entry == NULL) {
+    spin_unlock (&rctx->lock);
+    return;
+  }
+
+  entry->cpu = cpu;
+
+  list_append (rctx->entries, &entry->link);
+
+  spin_unlock (&rctx->lock);
+}