diff options
Diffstat (limited to 'drivers/xen/balloon.c')
| -rw-r--r-- | drivers/xen/balloon.c | 90 |
1 files changed, 80 insertions, 10 deletions
diff --git a/drivers/xen/balloon.c b/drivers/xen/balloon.c index 7ec933d505d2..25fd1bd949d8 100644 --- a/drivers/xen/balloon.c +++ b/drivers/xen/balloon.c @@ -55,6 +55,7 @@ #include <linux/memory_hotplug.h> #include <linux/percpu-defs.h> #include <linux/slab.h> +#include <linux/sysctl.h> #include <asm/page.h> #include <asm/pgalloc.h> @@ -71,6 +72,46 @@ #include <xen/features.h> #include <xen/page.h> +static int xen_hotplug_unpopulated; + +#ifdef CONFIG_XEN_BALLOON_MEMORY_HOTPLUG + +static int zero; +static int one = 1; + +static struct ctl_table balloon_table[] = { + { + .procname = "hotplug_unpopulated", + .data = &xen_hotplug_unpopulated, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec_minmax, + .extra1 = &zero, + .extra2 = &one, + }, + { } +}; + +static struct ctl_table balloon_root[] = { + { + .procname = "balloon", + .mode = 0555, + .child = balloon_table, + }, + { } +}; + +static struct ctl_table xen_root[] = { + { + .procname = "xen", + .mode = 0555, + .child = balloon_root, + }, + { } +}; + +#endif + /* * balloon_process() state: * @@ -99,6 +140,7 @@ static xen_pfn_t frame_list[PAGE_SIZE / sizeof(unsigned long)]; /* List of ballooned pages, threaded through the mem_map array. */ static LIST_HEAD(ballooned_pages); +static DECLARE_WAIT_QUEUE_HEAD(balloon_wq); /* Main work function, always executed in process context. */ static void balloon_process(struct work_struct *work); @@ -127,6 +169,7 @@ static void __balloon_append(struct page *page) list_add(&page->lru, &ballooned_pages); balloon_stats.balloon_low++; } + wake_up(&balloon_wq); } static void balloon_append(struct page *page) @@ -242,7 +285,8 @@ static enum bp_state reserve_additional_memory(void) int nid, rc; unsigned long balloon_hotplug; - credit = balloon_stats.target_pages - balloon_stats.total_pages; + credit = balloon_stats.target_pages + balloon_stats.target_unpopulated + - balloon_stats.total_pages; /* * Already hotplugged enough pages? Wait for them to be @@ -323,7 +367,7 @@ static struct notifier_block xen_memory_nb = { static enum bp_state reserve_additional_memory(void) { balloon_stats.target_pages = balloon_stats.current_pages; - return BP_DONE; + return BP_ECANCELED; } #endif /* CONFIG_XEN_BALLOON_MEMORY_HOTPLUG */ @@ -516,6 +560,28 @@ void balloon_set_new_target(unsigned long target) } EXPORT_SYMBOL_GPL(balloon_set_new_target); +static int add_ballooned_pages(int nr_pages) +{ + enum bp_state st; + + if (xen_hotplug_unpopulated) { + st = reserve_additional_memory(); + if (st != BP_ECANCELED) { + mutex_unlock(&balloon_mutex); + wait_event(balloon_wq, + !list_empty(&ballooned_pages)); + mutex_lock(&balloon_mutex); + return 0; + } + } + + st = decrease_reservation(nr_pages, GFP_USER); + if (st != BP_DONE) + return -ENOMEM; + + return 0; +} + /** * alloc_xenballooned_pages - get pages that have been ballooned out * @nr_pages: Number of pages to get @@ -526,27 +592,28 @@ int alloc_xenballooned_pages(int nr_pages, struct page **pages) { int pgno = 0; struct page *page; + int ret; + mutex_lock(&balloon_mutex); + + balloon_stats.target_unpopulated += nr_pages; + while (pgno < nr_pages) { page = balloon_retrieve(true); if (page) { pages[pgno++] = page; } else { - enum bp_state st; - st = decrease_reservation(nr_pages - pgno, GFP_USER); - if (st != BP_DONE) + ret = add_ballooned_pages(nr_pages - pgno); + if (ret < 0) goto out_undo; } } mutex_unlock(&balloon_mutex); return 0; out_undo: - while (pgno) - balloon_append(pages[--pgno]); - /* Free the memory back to the kernel soon */ - schedule_delayed_work(&balloon_worker, 0); mutex_unlock(&balloon_mutex); - return -ENOMEM; + free_xenballooned_pages(pgno, pages); + return ret; } EXPORT_SYMBOL(alloc_xenballooned_pages); @@ -566,6 +633,8 @@ void free_xenballooned_pages(int nr_pages, struct page **pages) balloon_append(pages[i]); } + balloon_stats.target_unpopulated -= nr_pages; + /* The balloon may be too large now. Shrink it if needed. */ if (current_credit()) schedule_delayed_work(&balloon_worker, 0); @@ -623,6 +692,7 @@ static int __init balloon_init(void) #ifdef CONFIG_XEN_BALLOON_MEMORY_HOTPLUG set_online_page_callback(&xen_online_page); register_memory_notifier(&xen_memory_nb); + register_sysctl_table(xen_root); #endif /* |