--- page_alloc.c	2001/07/02 15:59:04	1.45
+++ page_alloc.c	2001/08/11 02:41:54
@@ -501,6 +501,13 @@
 			return page;
 	}
 
+	/* desperation */
+	if (order == 0) {
+		extern struct page *kspared_alloc(void);
+		page = kspared_alloc();
+		if (page) return page;
+	}
+
 	/* No luck.. */
 	printk(KERN_ERR "__alloc_pages: %lu-order allocation failed.\n", order);
 	return NULL;
--- vmscan.c	2001/07/05 21:03:50	1.62
+++ vmscan.c	2001/08/11 02:41:55
@@ -1049,12 +1049,97 @@
 }
 
 
+struct spare {
+	struct spare *next;
+	struct page *page;
+};
+static struct spare *avail_list;
+static struct spare *used_list;
+static struct semaphore	kspared_sem;
+
+struct page *kspared_alloc(void)
+{
+	struct page *page;
+	struct spare *s;
+
+	if (avail_list == NULL) {
+		printk("kspared oom - sorry\n");
+		return NULL;
+	}
+
+	down(&kspared_sem);
+	if (avail_list == NULL) {
+		up(&kspared_sem);
+		return NULL;
+	}
+
+	s = avail_list;
+	avail_list = s->next;
+	page = s->page;
+	s->next = used_list;
+	s->page = NULL;
+	used_list = s;
+
+	up(&kspared_sem);
+	printk("kspared to the rescue!\n");
+	return page;
+}
+
+int kspared(void *unused)
+{
+	struct task_struct *tsk = current;
+	int interval = HZ;
+	int num_reserved = 25000;
+	int i;
+
+	daemonize();
+	strcpy(tsk->comm, "kspared");
+	sigfillset(&tsk->blocked);
+	current->flags |= PF_MEMALLOC;
+
+	init_MUTEX(&kspared_sem);
+
+	for (i=0; i<num_reserved; i++) {
+		struct spare *s;
+		s = (struct spare *)kmalloc(sizeof(*s), GFP_KERNEL);
+		if (!s) break;
+		down(&kspared_sem);
+		s->next = used_list;
+		s->page = NULL;
+		used_list = s;
+		up(&kspared_sem);
+	}
+
+	printk("kspared started with %d reserved pages\n", i);
+
+	while (1) {
+		tsk->state = TASK_INTERRUPTIBLE;
+		schedule_timeout(interval);
+
+		while (used_list) {
+			struct page *page = alloc_pages(GFP_KERNEL, 0);
+			struct spare *s;
+			if (!page) break;
+			down(&kspared_sem);
+			s = used_list;
+			used_list = used_list->next;
+			s->next = avail_list;
+			s->page = page;
+			avail_list = s;
+			up(&kspared_sem);
+			if (!used_list) printk("kspared refilled\n");
+		}
+	}
+}
+
+
 static int __init kswapd_init(void)
 {
 	printk("Starting kswapd v1.8\n");
 	swap_setup();
 	kernel_thread(kswapd, NULL, CLONE_FS | CLONE_FILES | CLONE_SIGNAL);
 	kernel_thread(kreclaimd, NULL, CLONE_FS | CLONE_FILES | CLONE_SIGNAL);
+	kernel_thread(kspared, NULL, CLONE_FS | CLONE_FILES | CLONE_SIGNAL);
 	return 0;
 }