diff options
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/mmap.c | 14 | ||||
| -rw-r--r-- | mm/nommu.c | 15 |
2 files changed, 29 insertions, 0 deletions
diff --git a/mm/mmap.c b/mm/mmap.c index 9a796c41e7d..7d416055f08 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -89,6 +89,20 @@ int sysctl_max_map_count __read_mostly = DEFAULT_MAX_MAP_COUNT; struct percpu_counter vm_committed_as ____cacheline_aligned_in_smp; /* + * The global memory commitment made in the system can be a metric + * that can be used to drive ballooning decisions when Linux is hosted + * as a guest. On Hyper-V, the host implements a policy engine for dynamically + * balancing memory across competing virtual machines that are hosted. + * Several metrics drive this policy engine including the guest reported + * memory commitment. + */ +unsigned long vm_memory_committed(void) +{ + return percpu_counter_read_positive(&vm_committed_as); +} +EXPORT_SYMBOL_GPL(vm_memory_committed); + +/* * Check that a process has enough memory to allocate a new virtual * mapping. 0 means there is enough memory for the allocation to * succeed and -ENOMEM implies there is not. diff --git a/mm/nommu.c b/mm/nommu.c index 45131b41bcd..79c3cac87af 100644 --- a/mm/nommu.c +++ b/mm/nommu.c @@ -66,6 +66,21 @@ int heap_stack_gap = 0; atomic_long_t mmap_pages_allocated; +/* + * The global memory commitment made in the system can be a metric + * that can be used to drive ballooning decisions when Linux is hosted + * as a guest. On Hyper-V, the host implements a policy engine for dynamically + * balancing memory across competing virtual machines that are hosted. + * Several metrics drive this policy engine including the guest reported + * memory commitment. + */ +unsigned long vm_memory_committed(void) +{ + return percpu_counter_read_positive(&vm_committed_as); +} + +EXPORT_SYMBOL_GPL(vm_memory_committed); + EXPORT_SYMBOL(mem_map); EXPORT_SYMBOL(num_physpages); |