Messages in this thread | | | Date | Wed, 22 Jul 2015 13:42:26 +0300 | From | "Kirill A. Shutemov" <> | Subject | Re: [PATCH V4 1/6] mm: mlock: Refactor mlock, munlock, and munlockall code |
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On Tue, Jul 21, 2015 at 03:59:36PM -0400, Eric B Munson wrote: > @@ -648,20 +656,23 @@ SYSCALL_DEFINE2(munlock, unsigned long, start, size_t, len) > start &= PAGE_MASK; > > down_write(¤t->mm->mmap_sem); > - ret = do_mlock(start, len, 0); > + ret = apply_vma_flags(start, len, flags, false); > up_write(¤t->mm->mmap_sem); > > return ret; > } > > +SYSCALL_DEFINE2(munlock, unsigned long, start, size_t, len) > +{ > + return do_munlock(start, len, VM_LOCKED); > +} > + > static int do_mlockall(int flags) > { > struct vm_area_struct * vma, * prev = NULL; > > if (flags & MCL_FUTURE) > current->mm->def_flags |= VM_LOCKED; > - else > - current->mm->def_flags &= ~VM_LOCKED;
I think this is wrong.
With current code mlockall(MCL_CURRENT) after mlockall(MCL_FUTURE | MCL_CURRENT) would undo future mlocking, without unlocking currently mlocked memory.
The change will break the use-case.
> if (flags == MCL_FUTURE) > goto out; >
-- Kirill A. Shutemov
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