On 09/23, Oleg Nesterov wrote: > > On 09/11, Kirill A. Shutemov wrote: > > > > This one is tricky. I *assume* the mm cannot be generally accessible after > > mm_users drops to zero, but I'm not entirely sure about it. > > procfs? ptrace? > > Well, all I can say is that proc/ptrace look fine afaics... > > This is off-topic, but how about the patch below? Different threads can > expand different vma's at the same time under read_lock(mmap_sem), so > vma_lock_anon_vma() can't help to serialize "locked_vm += grow". perhaps vm_stat_account() should be moved too, but total_vm/etc is less important. Or I missed something? Oleg. > --- x/mm/mmap.c > +++ x/mm/mmap.c > @@ -2146,9 +2146,6 @@ static int acct_stack_growth(struct vm_a > if (security_vm_enough_memory_mm(mm, grow)) > return -ENOMEM; > > - /* Ok, everything looks good - let it rip */ > - if (vma->vm_flags & VM_LOCKED) > - mm->locked_vm += grow; > vm_stat_account(mm, vma->vm_flags, vma->vm_file, grow); > return 0; > } > @@ -2210,6 +2207,8 @@ int expand_upwards(struct vm_area_struct > * against concurrent vma expansions. > */ > spin_lock(&vma->vm_mm->page_table_lock); > + if (vma->vm_flags & VM_LOCKED) > + mm->locked_vm += grow; > anon_vma_interval_tree_pre_update_vma(vma); > vma->vm_end = address; > anon_vma_interval_tree_post_update_vma(vma); > @@ -2281,6 +2280,8 @@ int expand_downwards(struct vm_area_stru > * against concurrent vma expansions. > */ > spin_lock(&vma->vm_mm->page_table_lock); > + if (vma->vm_flags & VM_LOCKED) > + mm->locked_vm += grow; > anon_vma_interval_tree_pre_update_vma(vma); > vma->vm_start = address; > vma->vm_pgoff -= grow; -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>