On Mon, 2011-02-28 at 12:44 +0100, Peter Zijlstra wrote: > unmap_region() > tlb_gather_mmu() > unmap_vmas() > for (; vma; vma = vma->vm_next) > unmao_page_range() > tlb_start_vma() -> flush cache range So why is this correct? Can't we race with a concurrent access to the memory region (munmap() vs other thread access race)? While unmap_region() callers will have removed the vma from the tree so faults will not be satisfied, TLBs might still be present and allow us to access the memory and thereby reloading it in the cache. > zap_*_range() > ptep_get_and_clear_full() -> batch/track external tlbs > tlb_remove_tlb_entry() -> batch/track external tlbs > tlb_remove_page() -> track range/batch page > tlb_end_vma() -> flush tlb range > > [ for architectures that have hardware page table walkers > concurrent faults can still load the page tables ] > > free_pgtables() > while (vma) > unlink_*_vma() > free_*_range() > *_free_tlb() > tlb_finish_mmu() > > free vmas -- To unsubscribe from this list: send the line "unsubscribe linux-arch" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
