diff options
| -rw-r--r-- | drivers/misc/vmw_balloon.c | 75 |
1 files changed, 52 insertions, 23 deletions
diff --git a/drivers/misc/vmw_balloon.c b/drivers/misc/vmw_balloon.c index 626abe65eddb..0d9f223d463e 100644 --- a/drivers/misc/vmw_balloon.c +++ b/drivers/misc/vmw_balloon.c @@ -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); } |
