Messages in this thread | | | Date | Tue, 30 Nov 2010 16:29:38 -0800 | From | Andrew Morton <> | Subject | Re: [PATCH RFC] vmalloc: eagerly clear ptes on vunmap |
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On Mon, 29 Nov 2010 12:32:11 -0800 Jeremy Fitzhardinge <jeremy@goop.org> wrote:
> When unmapping a region in the vmalloc space, clear the ptes immediately. > There's no point in deferring this because there's no amortization > benefit. > > The TLBs are left dirty, and they are flushed lazily to amortize the > cost of the IPIs. > > This specific motivation for this patch is a regression since 2.6.36 when > using NFS under Xen, triggered by the NFS client's use of vm_map_ram() > introduced in 56e4ebf877b6043c289bda32a5a7385b80c17dee. XFS also uses > vm_map_ram() and could cause similar problems. >
Do we have any quantitative info on that regression? The patch fixed it, I assume?
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