powerpc64/pmap: micro-optimize some PVO-PTE logic
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Authored by jhibbits on Nov 13 2019, 2:02 AM.

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nwhitehorn
luporl
bdragon

Commits

rS355519: powerpc64/pmap: micro-optimize some PVO-PTE logic

Summary

moea64_pte_sync_native() and moea64_pte_unset_native() don't need the
full PTE created, they only need to check that the PVO has a matching
PTE to the PTE in the page table. Don't waste time creating the full
PTE in this case.

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rS FreeBSD src repository - subversion

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Event Timeline

jhibbits created this revision.Nov 13 2019, 2:02 AM

Harbormaster completed remote builds in B27485: Diff 64263.Nov 13 2019, 2:02 AM

The changes look ok to me. They seem to preserve the original logic, while avoiding the full PTE from PVO conversion.

Looking further ahead, pseries MMU code could also be improved in a similar way.
mphyp_pte_unset() could take advantage of this optimization too, while the 'if' at mmu_phyp.c:288, at mphyp_pte_synch(), could now be refactored to use moea64_pte_vpn_from_pvo_vpn() instead.

This revision is now accepted and ready to land.Nov 29 2019, 1:16 PM

Closed by commit rS355519: powerpc64/pmap: micro-optimize some PVO-PTE logic (authored by jhibbits). · Explain WhyDec 8 2019, 4:17 AM

This revision was automatically updated to reflect the committed changes.

jhibbits added a commit: rS355519: powerpc64/pmap: micro-optimize some PVO-PTE logic.

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