1 files changed, 191 insertions, 240 deletions

diff --git a/arch/powerpc/platforms/pseries/cmm.c b/arch/powerpc/platforms/pseries/cmm.c
index b33251d75927..91571841df8a 100644
--- a/arch/powerpc/platforms/pseries/cmm.c
+++ b/arch/powerpc/platforms/pseries/cmm.c
@@ -19,6 +19,10 @@
 #include <linux/stringify.h>
 #include <linux/swap.h>
 #include <linux/device.h>
+#include <linux/mount.h>
+#include <linux/pseudo_fs.h>
+#include <linux/magic.h>
+#include <linux/balloon_compaction.h>
 #include <asm/firmware.h>
 #include <asm/hvcall.h>
 #include <asm/mmu.h>
@@ -38,12 +42,8 @@
 #define CMM_MIN_MEM_MB		256
 #define KB2PAGES(_p)		((_p)>>(PAGE_SHIFT-10))
 #define PAGES2KB(_p)		((_p)<<(PAGE_SHIFT-10))
-/*
- * The priority level tries to ensure that this notifier is called as
- * late as possible to reduce thrashing in the shared memory pool.
- */
+
 #define CMM_MEM_HOTPLUG_PRI	1
-#define CMM_MEM_ISOLATE_PRI	15
 
 static unsigned int delay = CMM_DEFAULT_DELAY;
 static unsigned int hotplug_delay = CMM_HOTPLUG_DELAY;
@@ -51,6 +51,8 @@ static unsigned int oom_kb = CMM_OOM_KB;
 static unsigned int cmm_debug = CMM_DEBUG;
 static unsigned int cmm_disabled = CMM_DISABLE;
 static unsigned long min_mem_mb = CMM_MIN_MEM_MB;
+static bool __read_mostly simulate;
+static unsigned long simulate_loan_target_kb;
 static struct device cmm_dev;
 
 MODULE_AUTHOR("Brian King <brking@linux.vnet.ibm.com>");
@@ -74,35 +76,31 @@ MODULE_PARM_DESC(min_mem_mb, "Minimum amount of memory (in MB) to not balloon. "
 module_param_named(debug, cmm_debug, uint, 0644);
 MODULE_PARM_DESC(debug, "Enable module debugging logging. Set to 1 to enable. "
 		 "[Default=" __stringify(CMM_DEBUG) "]");
-
-#define CMM_NR_PAGES ((PAGE_SIZE - sizeof(void *) - sizeof(unsigned long)) / sizeof(unsigned long))
+module_param_named(simulate, simulate, bool, 0444);
+MODULE_PARM_DESC(simulate, "Enable simulation mode (no communication with hw).");
 
 #define cmm_dbg(...) if (cmm_debug) { printk(KERN_INFO "cmm: "__VA_ARGS__); }
 
-struct cmm_page_array {
-	struct cmm_page_array *next;
-	unsigned long index;
-	unsigned long page[CMM_NR_PAGES];
-};
-
-static unsigned long loaned_pages;
+static atomic_long_t loaned_pages;
 static unsigned long loaned_pages_target;
 static unsigned long oom_freed_pages;
 
-static struct cmm_page_array *cmm_page_list;
-static DEFINE_SPINLOCK(cmm_lock);
-
 static DEFINE_MUTEX(hotplug_mutex);
 static int hotplug_occurred; /* protected by the hotplug mutex */
 
 static struct task_struct *cmm_thread_ptr;
+static struct balloon_dev_info b_dev_info;
 
-static long plpar_page_set_loaned(unsigned long vpa)
+static long plpar_page_set_loaned(struct page *page)
 {
+	const unsigned long vpa = page_to_phys(page);
 	unsigned long cmo_page_sz = cmo_get_page_size();
 	long rc = 0;
 	int i;
 
+	if (unlikely(simulate))
+		return 0;
+
 	for (i = 0; !rc && i < PAGE_SIZE; i += cmo_page_sz)
 		rc = plpar_hcall_norets(H_PAGE_INIT, H_PAGE_SET_LOANED, vpa + i, 0);
 
@@ -113,12 +111,16 @@ static long plpar_page_set_loaned(unsigned long vpa)
 	return rc;
 }
 
-static long plpar_page_set_active(unsigned long vpa)
+static long plpar_page_set_active(struct page *page)
 {
+	const unsigned long vpa = page_to_phys(page);
 	unsigned long cmo_page_sz = cmo_get_page_size();
 	long rc = 0;
 	int i;
 
+	if (unlikely(simulate))
+		return 0;
+
 	for (i = 0; !rc && i < PAGE_SIZE; i += cmo_page_sz)
 		rc = plpar_hcall_norets(H_PAGE_INIT, H_PAGE_SET_ACTIVE, vpa + i, 0);
 
@@ -138,8 +140,7 @@ static long plpar_page_set_active(unsigned long vpa)
  **/
 static long cmm_alloc_pages(long nr)
 {
-	struct cmm_page_array *pa, *npa;
-	unsigned long addr;
+	struct page *page;
 	long rc;
 
 	cmm_dbg("Begin request for %ld pages\n", nr);
@@ -156,46 +157,19 @@ static long cmm_alloc_pages(long nr)
 			break;
 		}
 
-		addr = __get_free_page(GFP_NOIO | __GFP_NOWARN |
-				       __GFP_NORETRY | __GFP_NOMEMALLOC);
-		if (!addr)
+		page = balloon_page_alloc();
+		if (!page)
 			break;
-		spin_lock(&cmm_lock);
-		pa = cmm_page_list;
-		if (!pa || pa->index >= CMM_NR_PAGES) {
-			/* Need a new page for the page list. */
-			spin_unlock(&cmm_lock);
-			npa = (struct cmm_page_array *)__get_free_page(
-					GFP_NOIO | __GFP_NOWARN |
-					__GFP_NORETRY | __GFP_NOMEMALLOC);
-			if (!npa) {
-				pr_info("%s: Can not allocate new page list\n", __func__);
-				free_page(addr);
-				break;
-			}
-			spin_lock(&cmm_lock);
-			pa = cmm_page_list;
-
-			if (!pa || pa->index >= CMM_NR_PAGES) {
-				npa->next = pa;
-				npa->index = 0;
-				pa = npa;
-				cmm_page_list = pa;
-			} else
-				free_page((unsigned long) npa);
-		}
-
-		if ((rc = plpar_page_set_loaned(__pa(addr)))) {
+		rc = plpar_page_set_loaned(page);
+		if (rc) {
 			pr_err("%s: Can not set page to loaned. rc=%ld\n", __func__, rc);
-			spin_unlock(&cmm_lock);
-			free_page(addr);
+			__free_page(page);
 			break;
 		}
 
-		pa->page[pa->index++] = addr;
-		loaned_pages++;
-		totalram_pages_dec();
-		spin_unlock(&cmm_lock);
+		balloon_page_enqueue(&b_dev_info, page);
+		atomic_long_inc(&loaned_pages);
+		adjust_managed_page_count(page, -1);
 		nr--;
 	}
 
@@ -212,30 +186,19 @@ static long cmm_alloc_pages(long nr)
  **/
 static long cmm_free_pages(long nr)
 {
-	struct cmm_page_array *pa;
-	unsigned long addr;
+	struct page *page;
 
 	cmm_dbg("Begin free of %ld pages.\n", nr);
-	spin_lock(&cmm_lock);
-	pa = cmm_page_list;
 	while (nr) {
-		if (!pa || pa->index <= 0)
+		page = balloon_page_dequeue(&b_dev_info);
+		if (!page)
 			break;
-		addr = pa->page[--pa->index];
-
-		if (pa->index == 0) {
-			pa = pa->next;
-			free_page((unsigned long) cmm_page_list);
-			cmm_page_list = pa;
-		}
-
-		plpar_page_set_active(__pa(addr));
-		free_page(addr);
-		loaned_pages--;
+		plpar_page_set_active(page);
+		adjust_managed_page_count(page, 1);
+		__free_page(page);
+		atomic_long_dec(&loaned_pages);
 		nr--;
-		totalram_pages_inc();
 	}
-	spin_unlock(&cmm_lock);
 	cmm_dbg("End request with %ld pages unfulfilled\n", nr);
 	return nr;
 }
@@ -257,7 +220,7 @@ static int cmm_oom_notify(struct notifier_block *self,
 
 	cmm_dbg("OOM processing started\n");
 	nr = cmm_free_pages(nr);
-	loaned_pages_target = loaned_pages;
+	loaned_pages_target = atomic_long_read(&loaned_pages);
 	*freed += KB2PAGES(oom_kb) - nr;
 	oom_freed_pages += KB2PAGES(oom_kb) - nr;
 	cmm_dbg("OOM processing complete\n");
@@ -274,19 +237,24 @@ static int cmm_oom_notify(struct notifier_block *self,
  **/
 static void cmm_get_mpp(void)
 {
+	const long __loaned_pages = atomic_long_read(&loaned_pages);
+	const long total_pages = totalram_pages() + __loaned_pages;
 	int rc;
 	struct hvcall_mpp_data mpp_data;
 	signed long active_pages_target, page_loan_request, target;
-	signed long total_pages = totalram_pages() + loaned_pages;
 	signed long min_mem_pages = (min_mem_mb * 1024 * 1024) / PAGE_SIZE;
 
-	rc = h_get_mpp(&mpp_data);
-
-	if (rc != H_SUCCESS)
-		return;
-
-	page_loan_request = div_s64((s64)mpp_data.loan_request, PAGE_SIZE);
-	target = page_loan_request + (signed long)loaned_pages;
+	if (likely(!simulate)) {
+		rc = h_get_mpp(&mpp_data);
+		if (rc != H_SUCCESS)
+			return;
+		page_loan_request = div_s64((s64)mpp_data.loan_request,
+					    PAGE_SIZE);
+		target = page_loan_request + __loaned_pages;
+	} else {
+		target = KB2PAGES(simulate_loan_target_kb);
+		page_loan_request = target - __loaned_pages;
+	}
 
 	if (target < 0 || total_pages < min_mem_pages)
 		target = 0;
@@ -307,7 +275,7 @@ static void cmm_get_mpp(void)
 	loaned_pages_target = target;
 
 	cmm_dbg("delta = %ld, loaned = %lu, target = %lu, oom = %lu, totalram = %lu\n",
-		page_loan_request, loaned_pages, loaned_pages_target,
+		page_loan_request, __loaned_pages, loaned_pages_target,
 		oom_freed_pages, totalram_pages());
 }
 
@@ -325,6 +293,7 @@ static struct notifier_block cmm_oom_nb = {
 static int cmm_thread(void *dummy)
 {
 	unsigned long timeleft;
+	long __loaned_pages;
 
 	while (1) {
 		timeleft = msleep_interruptible(delay * 1000);
@@ -355,11 +324,12 @@ static int cmm_thread(void *dummy)
 
 		cmm_get_mpp();
 
-		if (loaned_pages_target > loaned_pages) {
-			if (cmm_alloc_pages(loaned_pages_target - loaned_pages))
-				loaned_pages_target = loaned_pages;
-		} else if (loaned_pages_target < loaned_pages)
-			cmm_free_pages(loaned_pages - loaned_pages_target);
+		__loaned_pages = atomic_long_read(&loaned_pages);
+		if (loaned_pages_target > __loaned_pages) {
+			if (cmm_alloc_pages(loaned_pages_target - __loaned_pages))
+				loaned_pages_target = __loaned_pages;
+		} else if (loaned_pages_target < __loaned_pages)
+			cmm_free_pages(__loaned_pages - loaned_pages_target);
 	}
 	return 0;
 }
@@ -373,7 +343,7 @@ static int cmm_thread(void *dummy)
 	}							\
 	static DEVICE_ATTR(name, 0444, show_##name, NULL)
 
-CMM_SHOW(loaned_kb, "%lu\n", PAGES2KB(loaned_pages));
+CMM_SHOW(loaned_kb, "%lu\n", PAGES2KB(atomic_long_read(&loaned_pages)));
 CMM_SHOW(loaned_target_kb, "%lu\n", PAGES2KB(loaned_pages_target));
 
 static ssize_t show_oom_pages(struct device *dev,
@@ -406,11 +376,18 @@ static struct device_attribute *cmm_attrs[] = {
 	&dev_attr_oom_freed_kb,
 };
 
+static DEVICE_ULONG_ATTR(simulate_loan_target_kb, 0644,
+			 simulate_loan_target_kb);
+
 static struct bus_type cmm_subsys = {
 	.name = "cmm",
 	.dev_name = "cmm",
 };
 
+static void cmm_release_device(struct device *dev)
+{
+}
+
 /**
  * cmm_sysfs_register - Register with sysfs
  *
@@ -426,6 +403,7 @@ static int cmm_sysfs_register(struct device *dev)
 
 	dev->id = 0;
 	dev->bus = &cmm_subsys;
+	dev->release = cmm_release_device;
 
 	if ((rc = device_register(dev)))
 		goto subsys_unregister;
@@ -435,6 +413,11 @@ static int cmm_sysfs_register(struct device *dev)
 			goto fail;
 	}
 
+	if (!simulate)
+		return 0;
+	rc = device_create_file(dev, &dev_attr_simulate_loan_target_kb.attr);
+	if (rc)
+		goto fail;
 	return 0;
 
 fail:
@@ -471,7 +454,7 @@ static int cmm_reboot_notifier(struct notifier_block *nb,
 		if (cmm_thread_ptr)
 			kthread_stop(cmm_thread_ptr);
 		cmm_thread_ptr = NULL;
-		cmm_free_pages(loaned_pages);
+		cmm_free_pages(atomic_long_read(&loaned_pages));
 	}
 	return NOTIFY_DONE;
 }
@@ -481,142 +464,6 @@ static struct notifier_block cmm_reboot_nb = {
 };
 
 /**
- * cmm_count_pages - Count the number of pages loaned in a particular range.
- *
- * @arg: memory_isolate_notify structure with address range and count
- *
- * Return value:
- *      0 on success
- **/
-static unsigned long cmm_count_pages(void *arg)
-{
-	struct memory_isolate_notify *marg = arg;
-	struct cmm_page_array *pa;
-	unsigned long start = (unsigned long)pfn_to_kaddr(marg->start_pfn);
-	unsigned long end = start + (marg->nr_pages << PAGE_SHIFT);
-	unsigned long idx;
-
-	spin_lock(&cmm_lock);
-	pa = cmm_page_list;
-	while (pa) {
-		if ((unsigned long)pa >= start && (unsigned long)pa < end)
-			marg->pages_found++;
-		for (idx = 0; idx < pa->index; idx++)
-			if (pa->page[idx] >= start && pa->page[idx] < end)
-				marg->pages_found++;
-		pa = pa->next;
-	}
-	spin_unlock(&cmm_lock);
-	return 0;
-}
-
-/**
- * cmm_memory_isolate_cb - Handle memory isolation notifier calls
- * @self:	notifier block struct
- * @action:	action to take
- * @arg:	struct memory_isolate_notify data for handler
- *
- * Return value:
- *	NOTIFY_OK or notifier error based on subfunction return value
- **/
-static int cmm_memory_isolate_cb(struct notifier_block *self,
-				 unsigned long action, void *arg)
-{
-	int ret = 0;
-
-	if (action == MEM_ISOLATE_COUNT)
-		ret = cmm_count_pages(arg);
-
-	return notifier_from_errno(ret);
-}
-
-static struct notifier_block cmm_mem_isolate_nb = {
-	.notifier_call = cmm_memory_isolate_cb,
-	.priority = CMM_MEM_ISOLATE_PRI
-};
-
-/**
- * cmm_mem_going_offline - Unloan pages where memory is to be removed
- * @arg: memory_notify structure with page range to be offlined
- *
- * Return value:
- *	0 on success
- **/
-static int cmm_mem_going_offline(void *arg)
-{
-	struct memory_notify *marg = arg;
-	unsigned long start_page = (unsigned long)pfn_to_kaddr(marg->start_pfn);
-	unsigned long end_page = start_page + (marg->nr_pages << PAGE_SHIFT);
-	struct cmm_page_array *pa_curr, *pa_last, *npa;
-	unsigned long idx;
-	unsigned long freed = 0;
-
-	cmm_dbg("Memory going offline, searching 0x%lx (%ld pages).\n",
-			start_page, marg->nr_pages);
-	spin_lock(&cmm_lock);
-
-	/* Search the page list for pages in the range to be offlined */
-	pa_last = pa_curr = cmm_page_list;
-	while (pa_curr) {
-		for (idx = (pa_curr->index - 1); (idx + 1) > 0; idx--) {
-			if ((pa_curr->page[idx] < start_page) ||
-			    (pa_curr->page[idx] >= end_page))
-				continue;
-
-			plpar_page_set_active(__pa(pa_curr->page[idx]));
-			free_page(pa_curr->page[idx]);
-			freed++;
-			loaned_pages--;
-			totalram_pages_inc();
-			pa_curr->page[idx] = pa_last->page[--pa_last->index];
-			if (pa_last->index == 0) {
-				if (pa_curr == pa_last)
-					pa_curr = pa_last->next;
-				pa_last = pa_last->next;
-				free_page((unsigned long)cmm_page_list);
-				cmm_page_list = pa_last;
-			}
-		}
-		pa_curr = pa_curr->next;
-	}
-
-	/* Search for page list structures in the range to be offlined */
-	pa_last = NULL;
-	pa_curr = cmm_page_list;
-	while (pa_curr) {
-		if (((unsigned long)pa_curr >= start_page) &&
-				((unsigned long)pa_curr < end_page)) {
-			npa = (struct cmm_page_array *)__get_free_page(
-					GFP_NOIO | __GFP_NOWARN |
-					__GFP_NORETRY | __GFP_NOMEMALLOC);
-			if (!npa) {
-				spin_unlock(&cmm_lock);
-				cmm_dbg("Failed to allocate memory for list "
-						"management. Memory hotplug "
-						"failed.\n");
-				return -ENOMEM;
-			}
-			memcpy(npa, pa_curr, PAGE_SIZE);
-			if (pa_curr == cmm_page_list)
-				cmm_page_list = npa;
-			if (pa_last)
-				pa_last->next = npa;
-			free_page((unsigned long) pa_curr);
-			freed++;
-			pa_curr = npa;
-		}
-
-		pa_last = pa_curr;
-		pa_curr = pa_curr->next;
-	}
-
-	spin_unlock(&cmm_lock);
-	cmm_dbg("Released %ld pages in the search range.\n", freed);
-
-	return 0;
-}
-
-/**
  * cmm_memory_cb - Handle memory hotplug notifier calls
  * @self:	notifier block struct
  * @action:	action to take
@@ -635,7 +482,6 @@ static int cmm_memory_cb(struct notifier_block *self,
 	case MEM_GOING_OFFLINE:
 		mutex_lock(&hotplug_mutex);
 		hotplug_occurred = 1;
-		ret = cmm_mem_going_offline(arg);
 		break;
 	case MEM_OFFLINE:
 	case MEM_CANCEL_OFFLINE:
@@ -656,6 +502,106 @@ static struct notifier_block cmm_mem_nb = {
 	.priority = CMM_MEM_HOTPLUG_PRI
 };
 
+#ifdef CONFIG_BALLOON_COMPACTION
+static struct vfsmount *balloon_mnt;
+
+static int cmm_init_fs_context(struct fs_context *fc)
+{
+	return init_pseudo(fc, PPC_CMM_MAGIC) ? 0 : -ENOMEM;
+}
+
+static struct file_system_type balloon_fs = {
+	.name = "ppc-cmm",
+	.init_fs_context = cmm_init_fs_context,
+	.kill_sb = kill_anon_super,
+};
+
+static int cmm_migratepage(struct balloon_dev_info *b_dev_info,
+			   struct page *newpage, struct page *page,
+			   enum migrate_mode mode)
+{
+	unsigned long flags;
+
+	/*
+	 * loan/"inflate" the newpage first.
+	 *
+	 * We might race against the cmm_thread who might discover after our
+	 * loan request that another page is to be unloaned. However, once
+	 * the cmm_thread runs again later, this error will automatically
+	 * be corrected.
+	 */
+	if (plpar_page_set_loaned(newpage)) {
+		/* Unlikely, but possible. Tell the caller not to retry now. */
+		pr_err_ratelimited("%s: Cannot set page to loaned.", __func__);
+		return -EBUSY;
+	}
+
+	/* balloon page list reference */
+	get_page(newpage);
+
+	spin_lock_irqsave(&b_dev_info->pages_lock, flags);
+	balloon_page_insert(b_dev_info, newpage);
+	balloon_page_delete(page);
+	b_dev_info->isolated_pages--;
+	spin_unlock_irqrestore(&b_dev_info->pages_lock, flags);
+
+	/*
+	 * activate/"deflate" the old page. We ignore any errors just like the
+	 * other callers.
+	 */
+	plpar_page_set_active(page);
+
+	/* balloon page list reference */
+	put_page(page);
+
+	return MIGRATEPAGE_SUCCESS;
+}
+
+static int cmm_balloon_compaction_init(void)
+{
+	int rc;
+
+	balloon_devinfo_init(&b_dev_info);
+	b_dev_info.migratepage = cmm_migratepage;
+
+	balloon_mnt = kern_mount(&balloon_fs);
+	if (IS_ERR(balloon_mnt)) {
+		rc = PTR_ERR(balloon_mnt);
+		balloon_mnt = NULL;
+		return rc;
+	}
+
+	b_dev_info.inode = alloc_anon_inode(balloon_mnt->mnt_sb);
+	if (IS_ERR(b_dev_info.inode)) {
+		rc = PTR_ERR(b_dev_info.inode);
+		b_dev_info.inode = NULL;
+		kern_unmount(balloon_mnt);
+		balloon_mnt = NULL;
+		return rc;
+	}
+
+	b_dev_info.inode->i_mapping->a_ops = &balloon_aops;
+	return 0;
+}
+static void cmm_balloon_compaction_deinit(void)
+{
+	if (b_dev_info.inode)
+		iput(b_dev_info.inode);
+	b_dev_info.inode = NULL;
+	kern_unmount(balloon_mnt);
+	balloon_mnt = NULL;
+}
+#else /* CONFIG_BALLOON_COMPACTION */
+static int cmm_balloon_compaction_init(void)
+{
+	return 0;
+}
+
+static void cmm_balloon_compaction_deinit(void)
+{
+}
+#endif /* CONFIG_BALLOON_COMPACTION */
+
 /**
  * cmm_init - Module initialization
  *
@@ -664,26 +610,31 @@ static struct notifier_block cmm_mem_nb = {
  **/
 static int cmm_init(void)
 {
-	int rc = -ENOMEM;
+	int rc;
 
-	if (!firmware_has_feature(FW_FEATURE_CMO))
+	if (!firmware_has_feature(FW_FEATURE_CMO) && !simulate)
 		return -EOPNOTSUPP;
 
-	if ((rc = register_oom_notifier(&cmm_oom_nb)) < 0)
+	rc = cmm_balloon_compaction_init();
+	if (rc)
 		return rc;
 
+	rc = register_oom_notifier(&cmm_oom_nb);
+	if (rc < 0)
+		goto out_balloon_compaction;
+
 	if ((rc = register_reboot_notifier(&cmm_reboot_nb)))
 		goto out_oom_notifier;
 
 	if ((rc = cmm_sysfs_register(&cmm_dev)))
 		goto out_reboot_notifier;
 
-	if (register_memory_notifier(&cmm_mem_nb) ||
-	    register_memory_isolate_notifier(&cmm_mem_isolate_nb))
+	rc = register_memory_notifier(&cmm_mem_nb);
+	if (rc)
 		goto out_unregister_notifier;
 
 	if (cmm_disabled)
-		return rc;
+		return 0;
 
 	cmm_thread_ptr = kthread_run(cmm_thread, NULL, "cmmthread");
 	if (IS_ERR(cmm_thread_ptr)) {
@@ -691,16 +642,16 @@ static int cmm_init(void)
 		goto out_unregister_notifier;
 	}
 
-	return rc;
-
+	return 0;
 out_unregister_notifier:
 	unregister_memory_notifier(&cmm_mem_nb);
-	unregister_memory_isolate_notifier(&cmm_mem_isolate_nb);
 	cmm_unregister_sysfs(&cmm_dev);
 out_reboot_notifier:
 	unregister_reboot_notifier(&cmm_reboot_nb);
 out_oom_notifier:
 	unregister_oom_notifier(&cmm_oom_nb);
+out_balloon_compaction:
+	cmm_balloon_compaction_deinit();
 	return rc;
 }
 
@@ -717,9 +668,9 @@ static void cmm_exit(void)
 	unregister_oom_notifier(&cmm_oom_nb);
 	unregister_reboot_notifier(&cmm_reboot_nb);
 	unregister_memory_notifier(&cmm_mem_nb);
-	unregister_memory_isolate_notifier(&cmm_mem_isolate_nb);
-	cmm_free_pages(loaned_pages);
+	cmm_free_pages(atomic_long_read(&loaned_pages));
 	cmm_unregister_sysfs(&cmm_dev);
+	cmm_balloon_compaction_deinit();
 }
 
 /**
@@ -739,7 +690,7 @@ static int cmm_set_disable(const char *val, const struct kernel_param *kp)
 		if (cmm_thread_ptr)
 			kthread_stop(cmm_thread_ptr);
 		cmm_thread_ptr = NULL;
-		cmm_free_pages(loaned_pages);
+		cmm_free_pages(atomic_long_read(&loaned_pages));
 	} else if (!disable && cmm_disabled) {
 		cmm_thread_ptr = kthread_run(cmm_thread, NULL, "cmmthread");
 		if (IS_ERR(cmm_thread_ptr))