Simplify some grab VM_ALLOC_ZERO callers now that grab will set the pagesvalid.
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Authored by jeff on Mar 11 2020, 8:26 PM.

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Reviewers

alc
kib
dougm
markj

Summary

There are a couple of cases where we want wiring like semantics for the page but it is simply never added to the page queue that I marked with XXX. These callers don't require the xbusy except to satisfy an assert.

The other cases only need the xbusy internally until valid is set. This gives us fewer places touching the page valid bits and more options for changing the requirements to modify them later while not affecting consumers further.

Test Plan

stress2

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Build Status

Buildable 29883
Build 27703: arc lint + arc unit

Event Timeline

jeff created this revision.Mar 11 2020, 8:26 PM

Harbormaster completed remote builds in B29883: Diff 69400.Mar 11 2020, 8:26 PM

jeff retitled this revision from Simplify some grab VM_ALLOC_ZERO callers now that grab will set the pages valid. to Simplify some grab VM_ALLOC_ZERO callers now that grab will set the pagesvalid..Mar 11 2020, 8:33 PM

jeff edited the summary of this revision. (Show Details)

jeff edited the test plan for this revision. (Show Details)

jeff added reviewers: alc, kib, dougm, markj.

jeff set the repository for this revision to rS FreeBSD src repository - subversion.

Herald added a subscriber: imp. · View Herald TranscriptMar 11 2020, 8:33 PM

kib added inline comments.Mar 12 2020, 10:52 PM

sys/compat/cloudabi/cloudabi_vdso.c
66	There is no point to even comment about wiring there. Pages are from the phys object, they are unmanaged. So might be it would be better to change asserts and allow return of non-busy non-wired pages for OBJ_UNMANAGED objects.
sys/compat/linux/linux_vdso.c
88	There too.