diff options
Diffstat (limited to 'drivers/misc/vmw_balloon.c')
| -rw-r--r-- | drivers/misc/vmw_balloon.c | 92 |
1 files changed, 11 insertions, 81 deletions
diff --git a/drivers/misc/vmw_balloon.c b/drivers/misc/vmw_balloon.c index e7cfc85f6961..400a1ccefc8e 100644 --- a/drivers/misc/vmw_balloon.c +++ b/drivers/misc/vmw_balloon.c @@ -55,25 +55,6 @@ MODULE_ALIAS("vmware_vmmemctl"); MODULE_LICENSE("GPL"); /* - * Various constants controlling rate of inflaint/deflating balloon, - * measured in pages. - */ - -/* - * Rates of memory allocaton when guest experiences memory pressure - * (driver performs sleeping allocations). - */ -#define VMW_BALLOON_RATE_ALLOC_MIN 512U -#define VMW_BALLOON_RATE_ALLOC_MAX 2048U -#define VMW_BALLOON_RATE_ALLOC_INC 16U - -/* - * When guest is under memory pressure, use a reduced page allocation - * rate for next several cycles. - */ -#define VMW_BALLOON_SLOW_CYCLES 4 - -/* * Use __GFP_HIGHMEM to allow pages from HIGHMEM zone. We don't * allow wait (__GFP_RECLAIM) for NOSLEEP page allocations. Use * __GFP_NOWARN, to suppress page allocation failure warnings. @@ -284,12 +265,6 @@ struct vmballoon { /* reset flag */ bool reset_required; - /* adjustment rates (pages per second) */ - unsigned int rate_alloc; - - /* slowdown page allocations for next few cycles */ - unsigned int slow_allocation_cycles; - unsigned long capabilities; struct vmballoon_batch_page *batch_page; @@ -797,8 +772,6 @@ static void vmballoon_add_batched_page(struct vmballoon *b, int idx, */ static void vmballoon_inflate(struct vmballoon *b) { - unsigned rate; - unsigned int allocations = 0; unsigned int num_pages = 0; int error = 0; gfp_t flags = VMW_PAGE_ALLOC_NOSLEEP; @@ -825,17 +798,9 @@ static void vmballoon_inflate(struct vmballoon *b) * Start with no sleep allocation rate which may be higher * than sleeping allocation rate. */ - if (b->slow_allocation_cycles) { - rate = b->rate_alloc; - is_2m_pages = false; - } else { - rate = UINT_MAX; - is_2m_pages = - b->supported_page_sizes == VMW_BALLOON_NUM_PAGE_SIZES; - } + is_2m_pages = b->supported_page_sizes == VMW_BALLOON_NUM_PAGE_SIZES; - pr_debug("%s - goal: %d, no-sleep rate: %u, sleep rate: %d\n", - __func__, b->target - b->size, rate, b->rate_alloc); + pr_debug("%s - goal: %d", __func__, b->target - b->size); while (!b->reset_required && b->size + num_pages * vmballoon_page_size(is_2m_pages) @@ -868,31 +833,24 @@ static void vmballoon_inflate(struct vmballoon *b) if (flags == VMW_PAGE_ALLOC_CANSLEEP) { /* * CANSLEEP page allocation failed, so guest - * is under severe memory pressure. Quickly - * decrease allocation rate. + * is under severe memory pressure. We just log + * the event, but do not stop the inflation + * due to its negative impact on performance. */ - b->rate_alloc = max(b->rate_alloc / 2, - VMW_BALLOON_RATE_ALLOC_MIN); STATS_INC(b->stats.sleep_alloc_fail); break; } /* * NOSLEEP page allocation failed, so the guest is - * under memory pressure. Let us slow down page - * allocations for next few cycles so that the guest - * gets out of memory pressure. Also, if we already - * allocated b->rate_alloc pages, let's pause, - * otherwise switch to sleeping allocations. + * under memory pressure. Slowing down page alloctions + * seems to be reasonable, but doing so might actually + * cause the hypervisor to throttle us down, resulting + * in degraded performance. We will count on the + * scheduler and standard memory management mechanisms + * for now. */ - b->slow_allocation_cycles = VMW_BALLOON_SLOW_CYCLES; - - if (allocations >= b->rate_alloc) - break; - flags = VMW_PAGE_ALLOC_CANSLEEP; - /* Lower rate for sleeping allocations. */ - rate = b->rate_alloc; continue; } @@ -906,28 +864,11 @@ static void vmballoon_inflate(struct vmballoon *b) } cond_resched(); - - if (allocations >= rate) { - /* We allocated enough pages, let's take a break. */ - break; - } } if (num_pages > 0) b->ops->lock(b, num_pages, is_2m_pages, &b->target); - /* - * We reached our goal without failures so try increasing - * allocation rate. - */ - if (error == 0 && allocations >= b->rate_alloc) { - unsigned int mult = allocations / b->rate_alloc; - - b->rate_alloc = - min(b->rate_alloc + mult * VMW_BALLOON_RATE_ALLOC_INC, - VMW_BALLOON_RATE_ALLOC_MAX); - } - vmballoon_release_refused_pages(b, true); vmballoon_release_refused_pages(b, false); } @@ -1122,9 +1063,6 @@ static void vmballoon_work(struct work_struct *work) if (b->reset_required) vmballoon_reset(b); - if (b->slow_allocation_cycles > 0) - b->slow_allocation_cycles--; - if (!b->reset_required && vmballoon_send_get_target(b, &target)) { /* update target, adjust size */ b->target = target; @@ -1168,11 +1106,6 @@ static int vmballoon_debug_show(struct seq_file *f, void *offset) "current: %8d pages\n", b->target, b->size); - /* format rate info */ - seq_printf(f, - "rateSleepAlloc: %8d pages/sec\n", - b->rate_alloc); - seq_printf(f, "\n" "timer: %8u\n" @@ -1279,9 +1212,6 @@ static int __init vmballoon_init(void) INIT_LIST_HEAD(&balloon.page_sizes[is_2m_pages].refused_pages); } - /* initialize rates */ - balloon.rate_alloc = VMW_BALLOON_RATE_ALLOC_MAX; - INIT_DELAYED_WORK(&balloon.dwork, vmballoon_work); error = vmballoon_debugfs_init(&balloon); |