Messages in this thread | | | Date | Mon, 13 Jul 2015 19:17:55 +0100 | From | Will Deacon <> | Subject | Re: [PATCH 3/3] arm64, mm: Use IPIs for TLB invalidation. |
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On Sat, Jul 11, 2015 at 09:25:23PM +0100, David Daney wrote: > From: David Daney <david.daney@cavium.com> > > Most broadcast TLB invalidations are unnecessary. So when > invalidating for a given mm/vma target the only the needed CPUs via > and IPI. > > For global TLB invalidations, also use IPI. > > Tested on Cavium ThunderX. > > This change reduces 'time make -j48' on kernel from 139s to 116s (83% > as long).
Any idea *why* you're seeing such an improvement? Some older kernels had a bug where we'd try to flush a negative (i.e. huge) range by page, so it would be nice to rule that out. I assume these measurements are using mainline?
Having TLBI responsible for that amount of a kernel build doesn't feel right to me and doesn't line-up with the profiles I'm used to seeing.
You have 16-bit ASIDs, right?
Will
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