vmw_balloon: refactor change size from vmballoon_work (8b079cd0) · Commits · 戴 / test

drivers/misc/vmw_balloon.c

+52 −23

Original line number	Diff line number	Diff line
		@@ -633,6 +633,37 @@ static void vmballoon_add_page(struct vmballoon b, int idx, struct page p)
		b->page = p;
		}

		/**
		* vmballoon_change - retrieve the required balloon change
		*
		* @b: pointer for the balloon.
		*
		* Return: the required change for the balloon size. A positive number
		* indicates inflation, a negative number indicates a deflation.
		*/
		static int64_t vmballoon_change(struct vmballoon *b)
		{
		int64_t size, target;

		size = b->size;
		target = b->target;

		/*
		* We must cast first because of int sizes
		* Otherwise we might get huge positives instead of negatives
		*/

		if (b->reset_required)
		return 0;

		/* consider a 2MB slack on deflate, unless the balloon is emptied */
		if (target < size && size - target < vmballoon_page_size(true) &&
		target != 0)
		return 0;

		return target - size;
		}

		/*
		* Inflate the balloon towards its target size. Note that we try to limit
		* the rate of allocation to make sure we are not choking the rest of the
		@@ -644,8 +675,6 @@ static void vmballoon_inflate(struct vmballoon *b)
		int error = 0;
		bool is_2m_pages;

		pr_debug("%s - size: %d, target %d\n", __func__, b->size, b->target);

		/*
		* First try NOSLEEP page allocations to inflate balloon.
		*
		@@ -667,11 +696,8 @@ static void vmballoon_inflate(struct vmballoon *b)
		*/
		is_2m_pages = b->supported_page_sizes == VMW_BALLOON_NUM_PAGE_SIZES;

		pr_debug("%s - goal: %d", __func__, b->target - b->size);

		while (!b->reset_required &&
		b->size + num_pages * vmballoon_page_size(is_2m_pages)
		< b->target) {
		while ((int64_t)(num_pages * vmballoon_page_size(is_2m_pages)) <
		vmballoon_change(b)) {
		struct page *page;

		STATS_INC(b->stats.alloc[is_2m_pages]);
		@@ -742,8 +768,6 @@ static void vmballoon_deflate(struct vmballoon *b)
		{
		unsigned is_2m_pages;

		pr_debug("%s - size: %d, target %d\n", __func__, b->size, b->target);

		/* free pages to reach target */
		for (is_2m_pages = 0; is_2m_pages < b->supported_page_sizes;
		is_2m_pages++) {
		@@ -753,11 +777,9 @@ static void vmballoon_deflate(struct vmballoon *b)
		&b->page_sizes[is_2m_pages];

		list_for_each_entry_safe(page, next, &page_size->pages, lru) {
		if (b->reset_required \|\|
		(b->target > 0 &&
		b->size - num_pages
		* vmballoon_page_size(is_2m_pages)
		< b->target + vmballoon_page_size(true)))
		if ((int64_t)(num_pages *
		vmballoon_page_size(is_2m_pages)) >=
		-vmballoon_change(b))
		break;

		list_del(&page->lru);
		@@ -921,28 +943,35 @@ static void vmballoon_reset(struct vmballoon *b)
		pr_err("failed to send guest ID to the host\n");
		}

		/*
		* Balloon work function: reset protocol, if needed, get the new size and
		* adjust balloon as needed. Repeat in 1 sec.
		/**
		* vmballoon_work - periodic balloon worker for reset, inflation and deflation.
		*
		* @work: pointer to the &work_struct which is provided by the workqueue.
		*
		* Resets the protocol if needed, gets the new size and adjusts balloon as
		* needed. Repeat in 1 sec.
		*/
		static void vmballoon_work(struct work_struct *work)
		{
		struct delayed_work *dwork = to_delayed_work(work);
		struct vmballoon *b = container_of(dwork, struct vmballoon, dwork);
		int64_t change = 0;

		STATS_INC(b->stats.timer);

		if (b->reset_required)
		vmballoon_reset(b);

		if (!b->reset_required && vmballoon_send_get_target(b)) {
		unsigned long target = b->target;
		if (vmballoon_send_get_target(b))
		change = vmballoon_change(b);

		if (change != 0) {
		pr_debug("%s - size: %u, target %u", __func__,
		b->size, b->target);

		/* update target, adjust size */
		if (b->size < target)
		if (change > 0)
		vmballoon_inflate(b);
		else if (target == 0 \|\|
		b->size > target + vmballoon_page_size(true))
		else /* (change < 0) */
		vmballoon_deflate(b);
		}

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