swap_pager: use pctrie_reclaim_callback in meta_free_all
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Authored by dougm on Jun 13 2024, 4:54 PM.

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rlibby
kib

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rGd2acf0a44709: swap_pager: pctrie_reclaim_cb in meta_free_all

Summary

Replace the lookup-remove loop in swp_pager_meta_free_all with a call to SWAP_PCTRIE_RECLAIM_CALLBACK, to eliminate repeated trie searches.

Test Plan

A kernel modified with this patch was flogged enough for it to do some actual swapping, with no obvious ill effects.

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rG FreeBSD src repository

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Event Timeline

dougm requested review of this revision.Jun 13 2024, 4:54 PM

dougm created this revision.

So, the previous pindex tracking was totally unnecessary, we always tear down the whole tree, correct? From what I can tell, it looks like swp_pager_meta_build maintains a SWAP_META_PAGES alignment invariant for the keys, so we should never have been hopping over another entry anyway.

This revision is now accepted and ready to land.Jun 13 2024, 6:00 PM

In D45583#1039993, @rlibby wrote:

So, the previous pindex tracking was totally unnecessary, we always tear down the whole tree, correct? From what I can tell, it looks like swp_pager_meta_build maintains a SWAP_META_PAGES alignment invariant for the keys, so we should never have been hopping over another entry anyway.

Yes, I think that's right.

Closed by commit rGd2acf0a44709: swap_pager: pctrie_reclaim_cb in meta_free_all (authored by dougm). · Explain WhyJun 13 2024, 6:53 PM

This revision was automatically updated to reflect the committed changes.

dougm added a commit: rGd2acf0a44709: swap_pager: pctrie_reclaim_cb in meta_free_all.

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