Messages in this thread | | | Date | Tue, 10 Oct 2006 20:18:24 +0100 (BST) | From | Hugh Dickins <> | Subject | RE: Hugepage regression |
| |
On Tue, 10 Oct 2006, Chen, Kenneth W wrote: > > With the pending shared page table for hugetlb currently sitting in -mm, > we serialize the all hugetlb unmap with a per file i_mmap_lock. This > race could well be solved by that pending patch? > > http://kernel.org/pub/linux/kernel/people/akpm/patches/2.6/2.6.19-rc1/2.6.19-rc1-mm1/broken-out/shared-page-table-for-hugetlb-page-v4.patch
Hey, nice try, Ken! But I don't think we can let you sneak shared pagetables into 2.6.19 that way ;)
Sorry for not noticing this bug in your original TLB flush fix, which had looked good to me.
Yes, I'd expect your i_mmap_lock to solve the problem: and since you're headed in that direction anyway, it makes most sense to use that solution rather than get into defining arrays, or sacrificing the lazy flush, or risking page_count races.
So please extract the __unmap_hugepage_range mods from your shared pagetable patch, and use that to fix the bug. But again, I protest the "if (vma->vm_file)" in your unmap_hugepage_range - how would a hugepage area ever have NULL vma->vm_file?
Hugh - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
| |