diff options
Diffstat (limited to 'drivers/xen/balloon.c')
| -rw-r--r-- | drivers/xen/balloon.c | 33 |
1 files changed, 27 insertions, 6 deletions
diff --git a/drivers/xen/balloon.c b/drivers/xen/balloon.c index 12eab503efd1..d46839f51e73 100644 --- a/drivers/xen/balloon.c +++ b/drivers/xen/balloon.c @@ -42,7 +42,6 @@ #include <linux/kernel.h> #include <linux/sched.h> #include <linux/errno.h> -#include <linux/module.h> #include <linux/mm.h> #include <linux/bootmem.h> #include <linux/pagemap.h> @@ -152,6 +151,8 @@ static DECLARE_WAIT_QUEUE_HEAD(balloon_wq); static void balloon_process(struct work_struct *work); static DECLARE_DELAYED_WORK(balloon_worker, balloon_process); +static void release_memory_resource(struct resource *resource); + /* When ballooning out (allocating memory to return to Xen) we don't really want the kernel to try too hard since that can trigger the oom killer. */ #define GFP_BALLOON \ @@ -257,7 +258,7 @@ static struct resource *additional_memory_resource(phys_addr_t size) return NULL; res->name = "System RAM"; - res->flags = IORESOURCE_MEM | IORESOURCE_BUSY; + res->flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY; ret = allocate_resource(&iomem_resource, res, size, 0, -1, @@ -268,6 +269,20 @@ static struct resource *additional_memory_resource(phys_addr_t size) return NULL; } +#ifdef CONFIG_SPARSEMEM + { + unsigned long limit = 1UL << (MAX_PHYSMEM_BITS - PAGE_SHIFT); + unsigned long pfn = res->start >> PAGE_SHIFT; + + if (pfn > limit) { + pr_err("New System RAM resource outside addressable RAM (%lu > %lu)\n", + pfn, limit); + release_memory_resource(res); + return NULL; + } + } +#endif + return res; } @@ -338,7 +353,16 @@ static enum bp_state reserve_additional_memory(void) } #endif - rc = add_memory_resource(nid, resource); + /* + * add_memory_resource() will call online_pages() which in its turn + * will call xen_online_page() callback causing deadlock if we don't + * release balloon_mutex here. Unlocking here is safe because the + * callers drop the mutex before trying again. + */ + mutex_unlock(&balloon_mutex); + rc = add_memory_resource(nid, resource, memhp_auto_online); + mutex_lock(&balloon_mutex); + if (rc) { pr_warn("Cannot add additional memory (%i)\n", rc); goto err; @@ -751,7 +775,4 @@ static int __init balloon_init(void) return 0; } - subsys_initcall(balloon_init); - -MODULE_LICENSE("GPL"); |
