#include <linux/memory.h>
#include <linux/memory_hotplug.h>
#include <linux/percpu-defs.h>
+#include <linux/slab.h>
#include <asm/page.h>
#include <asm/pgalloc.h>
* 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
};
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.total_pages;
+
+ /*
+ * Already hotplugged enough pages? Wait for them to be
+ * onlined.
+ */
+ if (credit <= 0)
+ return BP_WAIT;
+
+ balloon_hotplug = round_up(credit, PAGES_PER_SECTION);
+
+ resource = additional_memory_resource(balloon_hotplug * PAGE_SIZE);
+ if (!resource)
+ goto err;
- 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);
+ 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_DONE;
}
+#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);
if (balloon_is_inflated())
state = increase_reservation(credit);
else
- state = reserve_additional_memory(credit);
+ state = reserve_additional_memory();
}
if (credit < 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);
#endif