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Commit de5a77d8 authored by David Vrabel's avatar David Vrabel
Browse files

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: default avatarDavid Vrabel <david.vrabel@citrix.com>
Reviewed-by: default avatarDaniel Kiper <daniel.kiper@oracle.com>
parent 55b3da98

drivers/xen/balloon.c

+12 −63
Original line number Diff line number Diff line
@@ -194,21 +194,6 @@ static enum bp_state update_schedule(enum bp_state state) 
}



#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 @@ static enum bp_state reserve_additional_memory(long credit) 
		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 @@ 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);

}
@@ -329,32 +306,22 @@ static struct notifier_block xen_memory_nb = { 
	.priority = 0

};

#else

static long current_credit(void)

static enum bp_state reserve_additional_memory(long credit)

{

	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)

{
@@ -367,15 +334,6 @@ 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);
@@ -438,15 +396,6 @@ static enum bp_state decrease_reservation(unsigned long nr_pages, gfp_t gfp) 
		.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 @@ static void __init balloon_add_region(unsigned long start_pfn, 
		   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 @@ 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;
@@ -659,9 +611,6 @@ static int __init balloon_init(void) 
	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

include/xen/balloon.h

+1 −4
Original line number Diff line number Diff line
@@ -11,14 +11,11 @@ struct balloon_stats { 
	/* 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;