Changes in kernel/generic/src/sysinfo/stats.c [fc47885:96b02eb9] in mainline

File:

• kernel/generic/src/sysinfo/stats.c (modified) (4 diffs)

kernel/generic/src/sysinfo/stats.c

@@ -160 +160 @@
 static size_t get_task_virtmem(as_t *as)
 {
+        size_t result = 0;
+
         /*
-         * We are holding spinlocks here and therefore are not allowed to
-         * block. Only attempt to lock the address space and address space
-         * area mutexes conditionally. If it is not possible to lock either
-         * object, return inexact statistics by skipping the respective object.
+         * We are holding some spinlocks here and therefore are not allowed to
+         * block. Only attempt to lock the address space and address space area
+         * mutexes conditionally. If it is not possible to lock either object,
+         * allow the statistics to be inexact by skipping the respective object.
+         *
+         * Note that it may be infinitely better to let the address space
+         * management code compute these statistics as it proceeds instead of
+         * having them calculated here over and over again here.
          */
-        
+
         if (SYNCH_FAILED(mutex_trylock(&as->lock)))
-                return 0;
-        
-        size_t pages = 0;
+                return result * PAGE_SIZE;
         
         /* Walk the B+ tree and count pages */
@@ -185 +189 @@
                         if (SYNCH_FAILED(mutex_trylock(&area->lock)))
                                 continue;
-                        
-                        pages += area->pages;
+                        result += area->pages;
                         mutex_unlock(&area->lock);
                 }
@@ -193 +196 @@
         mutex_unlock(&as->lock);
         
-        return (pages << PAGE_WIDTH);
-}
-
-/** Get the resident (used) size of a virtual address space
- *
- * @param as Address space.
- *
- * @return Size of the resident (used) virtual address space (bytes).
- *
- */
-static size_t get_task_resmem(as_t *as)
-{
-        /*
-         * We are holding spinlocks here and therefore are not allowed to
-         * block. Only attempt to lock the address space and address space
-         * area mutexes conditionally. If it is not possible to lock either
-         * object, return inexact statistics by skipping the respective object.
-         */
-        
-        if (SYNCH_FAILED(mutex_trylock(&as->lock)))
-                return 0;
-        
-        size_t pages = 0;
-        
-        /* Walk the B+ tree and count pages */
-        link_t *cur;
-        for (cur = as->as_area_btree.leaf_head.next;
-            cur != &as->as_area_btree.leaf_head; cur = cur->next) {
-                btree_node_t *node =
-                    list_get_instance(cur, btree_node_t, leaf_link);
-                
-                unsigned int i;
-                for (i = 0; i < node->keys; i++) {
-                        as_area_t *area = node->value[i];
-                        
-                        if (SYNCH_FAILED(mutex_trylock(&area->lock)))
-                                continue;
-                        
-                        pages += area->resident;
-                        mutex_unlock(&area->lock);
-                }
-        }
-        
-        mutex_unlock(&as->lock);
-        
-        return (pages << PAGE_WIDTH);
+        return result * PAGE_SIZE;
 }
 
@@ -257 +215 @@
         str_cpy(stats_task->name, TASK_NAME_BUFLEN, task->name);
         stats_task->virtmem = get_task_virtmem(task->as);
-        stats_task->resmem = get_task_resmem(task->as);
         stats_task->threads = atomic_get(&task->refcount);
         task_get_accounting(task, &(stats_task->ucycles),