#include <linux/memory.h>
#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>
#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:
*
* BP_DONE: done or nothing to do,
+ * BP_WAIT: wait to be rescheduled,
* BP_EAGAIN: error, go to sleep,
* BP_ECANCELED: error, balloon operation canceled.
*/
enum bp_state {
BP_DONE,
+ BP_WAIT,
BP_EAGAIN,
BP_ECANCELED
};
/* 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);
list_add(&page->lru, &ballooned_pages);
balloon_stats.balloon_low++;
}
+ wake_up(&balloon_wq);
}
static void balloon_append(struct page *page)
}
/* balloon_retrieve: rescue a page from the balloon, if it is not empty. */
-static struct page *balloon_retrieve(bool prefer_highmem)
+static struct page *balloon_retrieve(bool require_lowmem)
{
struct page *page;
if (list_empty(&ballooned_pages))
return NULL;
- if (prefer_highmem)
- page = list_entry(ballooned_pages.prev, struct page, lru);
- else
- page = list_entry(ballooned_pages.next, struct page, lru);
+ page = list_entry(ballooned_pages.next, struct page, lru);
+ if (require_lowmem && PageHighMem(page))
+ return NULL;
list_del(&page->lru);
if (PageHighMem(page))
static enum bp_state update_schedule(enum bp_state state)
{
+ if (state == BP_WAIT)
+ return BP_WAIT;
+
if (state == BP_ECANCELED)
return BP_ECANCELED;
}
#ifdef CONFIG_XEN_BALLOON_MEMORY_HOTPLUG
-static long current_credit(void)
+static struct resource *additional_memory_resource(phys_addr_t size)
{
- return balloon_stats.target_pages - balloon_stats.current_pages -
- balloon_stats.hotplug_pages;
+ struct resource *res;
+ int ret;
+
+ res = kzalloc(sizeof(*res), GFP_KERNEL);
+ if (!res)
+ return NULL;
+
+ res->name = "System RAM";
+ res->flags = IORESOURCE_MEM | IORESOURCE_BUSY;
+
+ ret = allocate_resource(&iomem_resource, res,
+ size, 0, -1,
+ PAGES_PER_SECTION * PAGE_SIZE, NULL, NULL);
+ if (ret < 0) {
+ pr_err("Cannot allocate new System RAM resource\n");
+ kfree(res);
+ return NULL;
+ }
+
+ return res;
}
-static bool balloon_is_inflated(void)
+static void release_memory_resource(struct resource *resource)
{
- if (balloon_stats.balloon_low || balloon_stats.balloon_high ||
- balloon_stats.balloon_hotplug)
- return true;
- else
- return false;
-}
+ if (!resource)
+ return;
-/*
- * reserve_additional_memory() adds memory region of size >= credit above
- * max_pfn. New region is section aligned and size is modified to be multiple
- * of section size. Those features allow optimal use of address space and
- * establish proper alignment when this function is called first time after
- * boot (last section not fully populated at boot time contains unused memory
- * pages with PG_reserved bit not set; online_pages_range() does not allow page
- * onlining in whole range if first onlined page does not have PG_reserved
- * bit set). Real size of added memory is established at page onlining stage.
- */
+ /*
+ * No need to reset region to identity mapped since we now
+ * know that no I/O can be in this region
+ */
+ release_resource(resource);
+ kfree(resource);
+}
-static enum bp_state reserve_additional_memory(long credit)
+static enum bp_state reserve_additional_memory(void)
{
+ long credit;
+ struct resource *resource;
int nid, rc;
- u64 hotplug_start_paddr;
- unsigned long balloon_hotplug = credit;
+ unsigned long balloon_hotplug;
+
+ credit = balloon_stats.target_pages + balloon_stats.target_unpopulated
+ - balloon_stats.total_pages;
+
+ /*
+ * Already hotplugged enough pages? Wait for them to be
+ * onlined.
+ */
+ if (credit <= 0)
+ return BP_WAIT;
- hotplug_start_paddr = PFN_PHYS(SECTION_ALIGN_UP(max_pfn));
- balloon_hotplug = round_up(balloon_hotplug, PAGES_PER_SECTION);
- nid = memory_add_physaddr_to_nid(hotplug_start_paddr);
+ balloon_hotplug = round_up(credit, PAGES_PER_SECTION);
+
+ resource = additional_memory_resource(balloon_hotplug * PAGE_SIZE);
+ if (!resource)
+ goto err;
+
+ nid = memory_add_physaddr_to_nid(resource->start);
#ifdef CONFIG_XEN_HAVE_PVMMU
/*
if (!xen_feature(XENFEAT_auto_translated_physmap)) {
unsigned long pfn, i;
- pfn = PFN_DOWN(hotplug_start_paddr);
+ pfn = PFN_DOWN(resource->start);
for (i = 0; i < balloon_hotplug; i++) {
if (!set_phys_to_machine(pfn + i, INVALID_P2M_ENTRY)) {
pr_warn("set_phys_to_machine() failed, no memory added\n");
- return BP_ECANCELED;
+ goto err;
}
}
}
#endif
- rc = add_memory(nid, hotplug_start_paddr, balloon_hotplug << PAGE_SHIFT);
-
+ rc = add_memory_resource(nid, resource);
if (rc) {
pr_warn("Cannot add additional memory (%i)\n", rc);
- return BP_ECANCELED;
+ goto err;
}
- balloon_hotplug -= credit;
-
- balloon_stats.hotplug_pages += credit;
- balloon_stats.balloon_hotplug = balloon_hotplug;
+ balloon_stats.total_pages += balloon_hotplug;
- return BP_DONE;
+ return BP_WAIT;
+ err:
+ release_memory_resource(resource);
+ return BP_ECANCELED;
}
static void xen_online_page(struct page *page)
__balloon_append(page);
- if (balloon_stats.hotplug_pages)
- --balloon_stats.hotplug_pages;
- else
- --balloon_stats.balloon_hotplug;
-
mutex_unlock(&balloon_mutex);
}
.priority = 0
};
#else
-static long current_credit(void)
+static enum bp_state reserve_additional_memory(void)
{
- unsigned long target = balloon_stats.target_pages;
-
- target = min(target,
- balloon_stats.current_pages +
- balloon_stats.balloon_low +
- balloon_stats.balloon_high);
-
- return target - balloon_stats.current_pages;
+ balloon_stats.target_pages = balloon_stats.current_pages;
+ return BP_ECANCELED;
}
+#endif /* CONFIG_XEN_BALLOON_MEMORY_HOTPLUG */
-static bool balloon_is_inflated(void)
+static long current_credit(void)
{
- if (balloon_stats.balloon_low || balloon_stats.balloon_high)
- return true;
- else
- return false;
+ return balloon_stats.target_pages - balloon_stats.current_pages;
}
-static enum bp_state reserve_additional_memory(long credit)
+static bool balloon_is_inflated(void)
{
- balloon_stats.target_pages = balloon_stats.current_pages;
- return BP_DONE;
+ return balloon_stats.balloon_low || balloon_stats.balloon_high;
}
-#endif /* CONFIG_XEN_BALLOON_MEMORY_HOTPLUG */
static enum bp_state increase_reservation(unsigned long nr_pages)
{
.domid = DOMID_SELF
};
-#ifdef CONFIG_XEN_BALLOON_MEMORY_HOTPLUG
- if (!balloon_stats.balloon_low && !balloon_stats.balloon_high) {
- nr_pages = min(nr_pages, balloon_stats.balloon_hotplug);
- balloon_stats.hotplug_pages += nr_pages;
- balloon_stats.balloon_hotplug -= nr_pages;
- return BP_DONE;
- }
-#endif
-
if (nr_pages > ARRAY_SIZE(frame_list))
nr_pages = ARRAY_SIZE(frame_list);
.domid = DOMID_SELF
};
-#ifdef CONFIG_XEN_BALLOON_MEMORY_HOTPLUG
- if (balloon_stats.hotplug_pages) {
- nr_pages = min(nr_pages, balloon_stats.hotplug_pages);
- balloon_stats.hotplug_pages -= nr_pages;
- balloon_stats.balloon_hotplug += nr_pages;
- return BP_DONE;
- }
-#endif
-
if (nr_pages > ARRAY_SIZE(frame_list))
nr_pages = ARRAY_SIZE(frame_list);
/* Update direct mapping, invalidate P2M, and add to balloon. */
for (i = 0; i < nr_pages; i++) {
pfn = frame_list[i];
- frame_list[i] = pfn_to_mfn(pfn);
+ frame_list[i] = pfn_to_gfn(pfn);
page = pfn_to_page(pfn);
#ifdef CONFIG_XEN_HAVE_PVMMU
if (balloon_is_inflated())
state = increase_reservation(credit);
else
- state = reserve_additional_memory(credit);
+ state = reserve_additional_memory();
}
if (credit < 0)
}
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
* @pages: pages returned
- * @highmem: allow highmem pages
* @return 0 on success, error otherwise
*/
-int alloc_xenballooned_pages(int nr_pages, struct page **pages, bool highmem)
+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(highmem);
- if (page && (highmem || !PageHighMem(page))) {
+ page = balloon_retrieve(true);
+ if (page) {
pages[pgno++] = page;
} else {
- enum bp_state st;
- if (page)
- balloon_append(page);
- st = decrease_reservation(nr_pages - pgno,
- highmem ? GFP_HIGHUSER : 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);
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);
don't subtract from it. */
__balloon_append(page);
}
+
+ balloon_stats.total_pages += extra_pfn_end - start_pfn;
}
static int __init balloon_init(void)
balloon_stats.target_pages = balloon_stats.current_pages;
balloon_stats.balloon_low = 0;
balloon_stats.balloon_high = 0;
+ balloon_stats.total_pages = balloon_stats.current_pages;
balloon_stats.schedule_delay = 1;
balloon_stats.max_schedule_delay = 32;
balloon_stats.max_retry_count = RETRY_UNLIMITED;
#ifdef CONFIG_XEN_BALLOON_MEMORY_HOTPLUG
- balloon_stats.hotplug_pages = 0;
- balloon_stats.balloon_hotplug = 0;
-
set_online_page_callback(&xen_online_page);
register_memory_notifier(&xen_memory_nb);
+ register_sysctl_table(xen_root);
#endif
/*
projects / cascardo / linux.git / blobdiff