diff options
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/memory.c | 2 | ||||
| -rw-r--r-- | mm/mlock.c | 47 | ||||
| -rw-r--r-- | mm/mmap.c | 48 | ||||
| -rw-r--r-- | mm/page-writeback.c | 21 | ||||
| -rw-r--r-- | mm/shmem.c | 2 | ||||
| -rw-r--r-- | mm/slub.c | 2 |
6 files changed, 45 insertions, 77 deletions
diff --git a/mm/memory.c b/mm/memory.c index 22bfa7a..baa999e 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -1999,7 +1999,7 @@ gotten: * Don't let another task, with possibly unlocked vma, * keep the mlocked page. */ - if (vma->vm_flags & VM_LOCKED) { + if ((vma->vm_flags & VM_LOCKED) && old_page) { lock_page(old_page); /* for LRU manipulation */ clear_page_mlock(old_page); unlock_page(old_page); @@ -294,14 +294,10 @@ static inline int __mlock_posix_error_return(long retval) * * return number of pages [> 0] to be removed from locked_vm on success * of "special" vmas. - * - * return negative error if vma spanning @start-@range disappears while - * mmap semaphore is dropped. Unlikely? */ long mlock_vma_pages_range(struct vm_area_struct *vma, unsigned long start, unsigned long end) { - struct mm_struct *mm = vma->vm_mm; int nr_pages = (end - start) / PAGE_SIZE; BUG_ON(!(vma->vm_flags & VM_LOCKED)); @@ -314,20 +310,8 @@ long mlock_vma_pages_range(struct vm_area_struct *vma, if (!((vma->vm_flags & (VM_DONTEXPAND | VM_RESERVED)) || is_vm_hugetlb_page(vma) || vma == get_gate_vma(current))) { - long error; - downgrade_write(&mm->mmap_sem); - - error = __mlock_vma_pages_range(vma, start, end, 1); - up_read(&mm->mmap_sem); - /* vma can change or disappear */ - down_write(&mm->mmap_sem); - vma = find_vma(mm, start); - /* non-NULL vma must contain @start, but need to check @end */ - if (!vma || end > vma->vm_end) - return -ENOMEM; - - return 0; /* hide other errors from mmap(), et al */ + return __mlock_vma_pages_range(vma, start, end, 1); } /* @@ -438,41 +422,14 @@ success: vma->vm_flags = newflags; if (lock) { - /* - * mmap_sem is currently held for write. Downgrade the write - * lock to a read lock so that other faults, mmap scans, ... - * while we fault in all pages. - */ - downgrade_write(&mm->mmap_sem); - ret = __mlock_vma_pages_range(vma, start, end, 1); - /* - * Need to reacquire mmap sem in write mode, as our callers - * expect this. We have no support for atomically upgrading - * a sem to write, so we need to check for ranges while sem - * is unlocked. - */ - up_read(&mm->mmap_sem); - /* vma can change or disappear */ - down_write(&mm->mmap_sem); - *prev = find_vma(mm, start); - /* non-NULL *prev must contain @start, but need to check @end */ - if (!(*prev) || end > (*prev)->vm_end) - ret = -ENOMEM; - else if (ret > 0) { + if (ret > 0) { mm->locked_vm -= ret; ret = 0; } else ret = __mlock_posix_error_return(ret); /* translate if needed */ } else { - /* - * TODO: for unlocking, pages will already be resident, so - * we don't need to wait for allocations/reclaim/pagein, ... - * However, unlocking a very large region can still take a - * while. Should we downgrade the semaphore for both lock - * AND unlock ? - */ __mlock_vma_pages_range(vma, start, end, 0); } @@ -1090,6 +1090,15 @@ int vma_wants_writenotify(struct vm_area_struct *vma) mapping_cap_account_dirty(vma->vm_file->f_mapping); } +/* + * We account for memory if it's a private writeable mapping, + * and VM_NORESERVE wasn't set. + */ +static inline int accountable_mapping(unsigned int vm_flags) +{ + return (vm_flags & (VM_NORESERVE | VM_SHARED | VM_WRITE)) == VM_WRITE; +} + unsigned long mmap_region(struct file *file, unsigned long addr, unsigned long len, unsigned long flags, unsigned int vm_flags, unsigned long pgoff, @@ -1117,23 +1126,24 @@ munmap_back: if (!may_expand_vm(mm, len >> PAGE_SHIFT)) return -ENOMEM; - if (flags & MAP_NORESERVE) + /* + * Set 'VM_NORESERVE' if we should not account for the + * memory use of this mapping. We only honor MAP_NORESERVE + * if we're allowed to overcommit memory. + */ + if ((flags & MAP_NORESERVE) && sysctl_overcommit_memory != OVERCOMMIT_NEVER) + vm_flags |= VM_NORESERVE; + if (!accountable) vm_flags |= VM_NORESERVE; - if (accountable && (!(flags & MAP_NORESERVE) || - sysctl_overcommit_memory == OVERCOMMIT_NEVER)) { - if (vm_flags & VM_SHARED) { - /* Check memory availability in shmem_file_setup? */ - vm_flags |= VM_ACCOUNT; - } else if (vm_flags & VM_WRITE) { - /* - * Private writable mapping: check memory availability - */ - charged = len >> PAGE_SHIFT; - if (security_vm_enough_memory(charged)) - return -ENOMEM; - vm_flags |= VM_ACCOUNT; - } + /* + * Private writable mapping: check memory availability + */ + if (accountable_mapping(vm_flags)) { + charged = len >> PAGE_SHIFT; + if (security_vm_enough_memory(charged)) + return -ENOMEM; + vm_flags |= VM_ACCOUNT; } /* @@ -1184,14 +1194,6 @@ munmap_back: goto free_vma; } - /* We set VM_ACCOUNT in a shared mapping's vm_flags, to inform - * shmem_zero_setup (perhaps called through /dev/zero's ->mmap) - * that memory reservation must be checked; but that reservation - * belongs to shared memory object, not to vma: so now clear it. - */ - if ((vm_flags & (VM_SHARED|VM_ACCOUNT)) == (VM_SHARED|VM_ACCOUNT)) - vma->vm_flags &= ~VM_ACCOUNT; - /* Can addr have changed?? * * Answer: Yes, several device drivers can do it in their diff --git a/mm/page-writeback.c b/mm/page-writeback.c index b493db7..dc32dae 100644 --- a/mm/page-writeback.c +++ b/mm/page-writeback.c @@ -1051,13 +1051,22 @@ continue_unlock: } } - if (wbc->sync_mode == WB_SYNC_NONE) { - wbc->nr_to_write--; - if (wbc->nr_to_write <= 0) { - done = 1; - break; - } + if (nr_to_write > 0) + nr_to_write--; + else if (wbc->sync_mode == WB_SYNC_NONE) { + /* + * We stop writing back only if we are not + * doing integrity sync. In case of integrity + * sync we have to keep going because someone + * may be concurrently dirtying pages, and we + * might have synced a lot of newly appeared + * dirty pages, but have not synced all of the + * old dirty pages. + */ + done = 1; + break; } + if (wbc->nonblocking && bdi_write_congested(bdi)) { wbc->encountered_congestion = 1; done = 1; @@ -2628,7 +2628,7 @@ struct file *shmem_file_setup(char *name, loff_t size, unsigned long flags) goto close_file; #ifdef CONFIG_SHMEM - SHMEM_I(inode)->flags = flags & VM_ACCOUNT; + SHMEM_I(inode)->flags = (flags & VM_NORESERVE) ? 0 : VM_ACCOUNT; #endif d_instantiate(dentry, inode); inode->i_size = size; @@ -1996,7 +1996,7 @@ static struct kmem_cache_cpu *alloc_kmem_cache_cpu(struct kmem_cache *s, static void free_kmem_cache_cpu(struct kmem_cache_cpu *c, int cpu) { if (c < per_cpu(kmem_cache_cpu, cpu) || - c > per_cpu(kmem_cache_cpu, cpu) + NR_KMEM_CACHE_CPU) { + c >= per_cpu(kmem_cache_cpu, cpu) + NR_KMEM_CACHE_CPU) { kfree(c); return; } |
