On Fri, Aug 22, 2014 at 12:51:47AM +0300, Kirill A. Shutemov wrote: > > > One thing: there could be (I haven't checked) complications on > > > vma_merge(): since vm_flags are identical it assumes that it can reuse > > > vma->vm_page_prot of expanded vma. But VM_SOFTDIRTY is excluded from > > > vm_flags compatibility check. What should we do with vm_page_prot there? > > > > Since the merged VMA will have VM_SOFTDIRTY set, it's OK that it's > > vm_page_prot > > won't be setup for write notifications. For the purpose of process > > migration, > > you'll just get some false positives, which is tolerable. > > Right. But should we disable writenotify back to avoid exessive wp-faults > if it was enabled due to soft-dirty (the case when expanded vma is > soft-dirty)?
Ah, I understand now. I've got a patch in the works that disables the write faults when a VMA is merged. I'll send a series with all of the changes tomorrow. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
