On Fri, Jul 24, 2015 at 12:47:43PM +0100, David Vrabel wrote:
> 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 the following commit when deciding whether
s/the following commit/"xen/balloon: only hotplug additional memory if required"
patch
> additional memory needs to be hotplugged.
>
> Signed-off-by: David Vrabel <david.vrabel@xxxxxxxxxx>
> ---
> drivers/xen/balloon.c | 75 +++++++++------------------------------------------
> include/xen/balloon.h | 5 +---
> 2 files changed, 13 insertions(+), 67 deletions(-)
>
> diff --git a/drivers/xen/balloon.c b/drivers/xen/balloon.c
> index 29aeb8f..b5037b1 100644
> --- a/drivers/xen/balloon.c
> +++ b/drivers/xen/balloon.c
> @@ -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;
> @@ -300,10 +285,7 @@ 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:
> @@ -319,11 +301,6 @@ 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);
> }
>
> @@ -340,32 +317,22 @@ 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)
> {
> @@ -378,15 +345,6 @@ 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);
>
> @@ -449,15 +407,6 @@ 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);
>
> @@ -647,6 +596,8 @@ 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)
> @@ -664,6 +615,7 @@ 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;
> @@ -671,9 +623,6 @@ 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
> 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 @@ 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;
> --
> 2.1.4
>
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