diff options
Diffstat (limited to 'mm/mmap.c')
| -rw-r--r-- | mm/mmap.c | 124 |
1 files changed, 0 insertions, 124 deletions
diff --git a/mm/mmap.c b/mm/mmap.c index 676f422f2e2c..14641926c97f 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -122,130 +122,6 @@ void vma_set_page_prot(struct vm_area_struct *vma) } } - -int sysctl_overcommit_memory __read_mostly = OVERCOMMIT_GUESS; /* heuristic overcommit */ -int sysctl_overcommit_ratio __read_mostly = 50; /* default is 50% */ -unsigned long sysctl_overcommit_kbytes __read_mostly; -int sysctl_max_map_count __read_mostly = DEFAULT_MAX_MAP_COUNT; -unsigned long sysctl_user_reserve_kbytes __read_mostly = 1UL << 17; /* 128MB */ -unsigned long sysctl_admin_reserve_kbytes __read_mostly = 1UL << 13; /* 8MB */ -/* - * Make sure vm_committed_as in one cacheline and not cacheline shared with - * other variables. It can be updated by several CPUs frequently. - */ -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. - * - * We currently support three overcommit policies, which are set via the - * vm.overcommit_memory sysctl. See Documentation/vm/overcommit-accounting - * - * Strict overcommit modes added 2002 Feb 26 by Alan Cox. - * Additional code 2002 Jul 20 by Robert Love. - * - * cap_sys_admin is 1 if the process has admin privileges, 0 otherwise. - * - * Note this is a helper function intended to be used by LSMs which - * wish to use this logic. - */ -int __vm_enough_memory(struct mm_struct *mm, long pages, int cap_sys_admin) -{ - long free, allowed, reserve; - - VM_WARN_ONCE(percpu_counter_read(&vm_committed_as) < - -(s64)vm_committed_as_batch * num_online_cpus(), - "memory commitment underflow"); - - vm_acct_memory(pages); - - /* - * Sometimes we want to use more memory than we have - */ - if (sysctl_overcommit_memory == OVERCOMMIT_ALWAYS) - return 0; - - if (sysctl_overcommit_memory == OVERCOMMIT_GUESS) { - free = global_page_state(NR_FREE_PAGES); - free += global_page_state(NR_FILE_PAGES); - - /* - * shmem pages shouldn't be counted as free in this - * case, they can't be purged, only swapped out, and - * that won't affect the overall amount of available - * memory in the system. - */ - free -= global_page_state(NR_SHMEM); - - free += get_nr_swap_pages(); - - /* - * Any slabs which are created with the - * SLAB_RECLAIM_ACCOUNT flag claim to have contents - * which are reclaimable, under pressure. The dentry - * cache and most inode caches should fall into this - */ - free += global_page_state(NR_SLAB_RECLAIMABLE); - - /* - * Leave reserved pages. The pages are not for anonymous pages. - */ - if (free <= totalreserve_pages) - goto error; - else - free -= totalreserve_pages; - - /* - * Reserve some for root - */ - if (!cap_sys_admin) - free -= sysctl_admin_reserve_kbytes >> (PAGE_SHIFT - 10); - - if (free > pages) - return 0; - - goto error; - } - - allowed = vm_commit_limit(); - /* - * Reserve some for root - */ - if (!cap_sys_admin) - allowed -= sysctl_admin_reserve_kbytes >> (PAGE_SHIFT - 10); - - /* - * Don't let a single process grow so big a user can't recover - */ - if (mm) { - reserve = sysctl_user_reserve_kbytes >> (PAGE_SHIFT - 10); - allowed -= min_t(long, mm->total_vm / 32, reserve); - } - - if (percpu_counter_read_positive(&vm_committed_as) < allowed) - return 0; -error: - vm_unacct_memory(pages); - - return -ENOMEM; -} - /* * Requires inode->i_mapping->i_mmap_rwsem */ |