xen/balloon: rationalize memory hotplug stats
The stats used for memory hotplug make no sense and are fiddled with
in odd ways. Remove them and introduce total_pages to track the total
number of pages (both populated and unpopulated) including those within
hotplugged regions (note that this includes not yet onlined pages).
This will be used in a subsequent commit (xen/balloon: only hotplug
additional memory if required) when deciding whether additional memory
needs to be hotplugged.
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
diff --git a/drivers/xen/balloon.c b/drivers/xen/balloon.c
index 095bb67..ac80547 100644
--- a/drivers/xen/balloon.c
+++ b/drivers/xen/balloon.c
@@ -194,21 +194,6 @@
}
#ifdef CONFIG_XEN_BALLOON_MEMORY_HOTPLUG
-static long current_credit(void)
-{
- return balloon_stats.target_pages - balloon_stats.current_pages -
- balloon_stats.hotplug_pages;
-}
-
-static bool balloon_is_inflated(void)
-{
- if (balloon_stats.balloon_low || balloon_stats.balloon_high ||
- balloon_stats.balloon_hotplug)
- return true;
- else
- return false;
-}
-
static struct resource *additional_memory_resource(phys_addr_t size)
{
struct resource *res;
@@ -289,10 +274,7 @@
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;
err:
@@ -308,11 +290,6 @@
__balloon_append(page);
- if (balloon_stats.hotplug_pages)
- --balloon_stats.hotplug_pages;
- else
- --balloon_stats.balloon_hotplug;
-
mutex_unlock(&balloon_mutex);
}
@@ -329,26 +306,6 @@
.priority = 0
};
#else
-static long current_credit(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;
-}
-
-static bool balloon_is_inflated(void)
-{
- if (balloon_stats.balloon_low || balloon_stats.balloon_high)
- return true;
- else
- return false;
-}
-
static enum bp_state reserve_additional_memory(long credit)
{
balloon_stats.target_pages = balloon_stats.current_pages;
@@ -356,6 +313,16 @@
}
#endif /* CONFIG_XEN_BALLOON_MEMORY_HOTPLUG */
+static long current_credit(void)
+{
+ return balloon_stats.target_pages - balloon_stats.current_pages;
+}
+
+static bool balloon_is_inflated(void)
+{
+ return balloon_stats.balloon_low || balloon_stats.balloon_high;
+}
+
static enum bp_state increase_reservation(unsigned long nr_pages)
{
int rc;
@@ -367,15 +334,6 @@
.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);
@@ -438,15 +396,6 @@
.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);
@@ -635,6 +584,8 @@
don't subtract from it. */
__balloon_append(page);
}
+
+ balloon_stats.total_pages += extra_pfn_end - start_pfn;
}
static int __init balloon_init(void)
@@ -652,6 +603,7 @@
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;
@@ -659,9 +611,6 @@
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
diff --git a/include/xen/balloon.h b/include/xen/balloon.h
index cc2e1a7..c8aee7a 100644
--- a/include/xen/balloon.h
+++ b/include/xen/balloon.h
@@ -11,14 +11,11 @@
/* Number of pages in high- and low-memory balloons. */
unsigned long balloon_low;
unsigned long balloon_high;
+ unsigned long total_pages;
unsigned long schedule_delay;
unsigned long max_schedule_delay;
unsigned long retry_count;
unsigned long max_retry_count;
-#ifdef CONFIG_XEN_BALLOON_MEMORY_HOTPLUG
- unsigned long hotplug_pages;
- unsigned long balloon_hotplug;
-#endif
};
extern struct balloon_stats balloon_stats;