#include <asm/xen/hypervisor.h>
#include <asm/xen/hypercall.h>
+
+#include <xen/xen.h>
#include <xen/interface/xen.h>
#include <xen/interface/memory.h>
#include <xen/xenbus.h>
/* We aim for 'current allocation' == 'target allocation'. */
unsigned long current_pages;
unsigned long target_pages;
- /* We may hit the hard limit in Xen. If we do then we remember it. */
- unsigned long hard_limit;
/*
* Drivers may alter the memory reservation independently, but they
* must inform the balloon driver so we avoid hitting the hard limit.
/* We increase/decrease in batches which fit in a page */
static unsigned long frame_list[PAGE_SIZE / sizeof(unsigned long)];
-/* VM /proc information for memory */
-extern unsigned long totalram_pages;
-
#ifdef CONFIG_HIGHMEM
-extern unsigned long totalhigh_pages;
#define inc_totalhigh_pages() (totalhigh_pages++)
#define dec_totalhigh_pages() (totalhigh_pages--)
#else
list_add(&page->lru, &ballooned_pages);
balloon_stats.balloon_low++;
}
+
+ totalram_pages--;
}
/* balloon_retrieve: rescue a page from the balloon, if it is not empty. */
else
balloon_stats.balloon_low--;
+ totalram_pages++;
+
return page;
}
static unsigned long current_target(void)
{
- unsigned long target = min(balloon_stats.target_pages, balloon_stats.hard_limit);
+ unsigned long target = balloon_stats.target_pages;
target = min(target,
balloon_stats.current_pages +
page = balloon_first_page();
for (i = 0; i < nr_pages; i++) {
BUG_ON(page == NULL);
- frame_list[i] = page_to_pfn(page);;
+ frame_list[i] = page_to_pfn(page);
page = balloon_next_page(page);
}
set_xen_guest_handle(reservation.extent_start, frame_list);
reservation.nr_extents = nr_pages;
rc = HYPERVISOR_memory_op(XENMEM_populate_physmap, &reservation);
- if (rc < nr_pages) {
- if (rc > 0) {
- int ret;
-
- /* We hit the Xen hard limit: reprobe. */
- reservation.nr_extents = rc;
- ret = HYPERVISOR_memory_op(XENMEM_decrease_reservation,
- &reservation);
- BUG_ON(ret != rc);
- }
- if (rc >= 0)
- balloon_stats.hard_limit = (balloon_stats.current_pages + rc -
- balloon_stats.driver_pages);
+ if (rc < 0)
goto out;
- }
- for (i = 0; i < nr_pages; i++) {
+ for (i = 0; i < rc; i++) {
page = balloon_retrieve();
BUG_ON(page == NULL);
__free_page(page);
}
- balloon_stats.current_pages += nr_pages;
- totalram_pages = balloon_stats.current_pages;
+ balloon_stats.current_pages += rc;
out:
spin_unlock_irqrestore(&balloon_lock, flags);
- return 0;
+ return rc < 0 ? rc : rc != nr_pages;
}
static int decrease_reservation(unsigned long nr_pages)
BUG_ON(ret != nr_pages);
balloon_stats.current_pages -= nr_pages;
- totalram_pages = balloon_stats.current_pages;
spin_unlock_irqrestore(&balloon_lock, flags);
static void balloon_set_new_target(unsigned long target)
{
/* No need for lock. Not read-modify-write updates. */
- balloon_stats.hard_limit = ~0UL;
balloon_stats.target_pages = target;
schedule_work(&balloon_worker);
}
pr_info("xen_balloon: Initialising balloon driver.\n");
balloon_stats.current_pages = min(xen_start_info->nr_pages, max_pfn);
- totalram_pages = balloon_stats.current_pages;
balloon_stats.target_pages = balloon_stats.current_pages;
balloon_stats.balloon_low = 0;
balloon_stats.balloon_high = 0;
balloon_stats.driver_pages = 0UL;
- balloon_stats.hard_limit = ~0UL;
init_timer(&balloon_timer);
balloon_timer.data = 0;
BALLOON_SHOW(current_kb, "%lu\n", PAGES2KB(balloon_stats.current_pages));
BALLOON_SHOW(low_kb, "%lu\n", PAGES2KB(balloon_stats.balloon_low));
BALLOON_SHOW(high_kb, "%lu\n", PAGES2KB(balloon_stats.balloon_high));
-BALLOON_SHOW(hard_limit_kb,
- (balloon_stats.hard_limit!=~0UL) ? "%lu\n" : "???\n",
- (balloon_stats.hard_limit!=~0UL) ? PAGES2KB(balloon_stats.hard_limit) : 0);
BALLOON_SHOW(driver_kb, "%lu\n", PAGES2KB(balloon_stats.driver_pages));
static ssize_t show_target_kb(struct sys_device *dev, struct sysdev_attribute *attr,
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
- target_bytes = memparse(buf, &endchar);
+ target_bytes = simple_strtoull(buf, &endchar, 0) * 1024;
balloon_set_new_target(target_bytes >> PAGE_SHIFT);
static SYSDEV_ATTR(target_kb, S_IRUGO | S_IWUSR,
show_target_kb, store_target_kb);
+
+static ssize_t show_target(struct sys_device *dev, struct sysdev_attribute *attr,
+ char *buf)
+{
+ return sprintf(buf, "%llu\n",
+ (unsigned long long)balloon_stats.target_pages
+ << PAGE_SHIFT);
+}
+
+static ssize_t store_target(struct sys_device *dev,
+ struct sysdev_attribute *attr,
+ const char *buf,
+ size_t count)
+{
+ char *endchar;
+ unsigned long long target_bytes;
+
+ if (!capable(CAP_SYS_ADMIN))
+ return -EPERM;
+
+ target_bytes = memparse(buf, &endchar);
+
+ balloon_set_new_target(target_bytes >> PAGE_SHIFT);
+
+ return count;
+}
+
+static SYSDEV_ATTR(target, S_IRUGO | S_IWUSR,
+ show_target, store_target);
+
+
static struct sysdev_attribute *balloon_attrs[] = {
&attr_target_kb,
+ &attr_target,
};
static struct attribute *balloon_info_attrs[] = {
&attr_current_kb.attr,
&attr_low_kb.attr,
&attr_high_kb.attr,
- &attr_hard_limit_kb.attr,
&attr_driver_kb.attr,
NULL
};