Use ATTR_DBM for ATTR_SW_DBM instead of a software bit.
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Authored by markj on Jul 30 2019, 8:20 PM.

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manu
andrew
alc

Commits

rS350525: Use ATTR_DBM even when hardware dirty bit management is not enabled.

Summary

On ARMv8.0 ATTR_DBM is reserved. But Linux uses it anyway, so I presume
it is safe to do so in FreeBSD as well.

I am torn on whether to keep using "ATTR_SW_DBM" or whether I should
just replace all references with ATTR_SW_DBM. Any preferences?

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Buildable 25609
Build 24207: arc lint + arc unit

Event Timeline

markj created this revision.Jul 30 2019, 8:20 PM

Herald added a reviewer: manu. · View Herald TranscriptJul 30 2019, 8:20 PM

Herald added subscribers: emaste, andrew. · View Herald Transcript

Harbormaster completed remote builds in B25609: Diff 60309.Jul 30 2019, 8:20 PM

markj added reviewers: andrew, alc.Jul 30 2019, 8:20 PM

Do we have access to a machine with hardware DBM support?

In D21121#458634, @alc wrote:

Do we have access to a machine with hardware DBM support?

Not yet. It looks like the thunderx2 does not support hardware DBM or AF management: http://dmesgd.nycbug.org/index.cgi?do=view&id=4798

I am torn on whether to keep using "ATTR_SW_DBM" or whether I should
just replace all references with ATTR_SW_DBM. Any preferences?

No, not really.

In D21121#458634, @alc wrote:

Do we have access to a machine with hardware DBM support?

As far as I know only in the form of a simulator, e.g. the Architecture Envelope Model from https://developer.arm.com/tools-and-software/simulation-models/fixed-virtual-platforms

andrew accepted this revision.Jul 31 2019, 11:59 AM

This revision is now accepted and ready to land.Jul 31 2019, 11:59 AM

alc accepted this revision.Jul 31 2019, 7:12 PM

Closed by commit rS350525: Use ATTR_DBM even when hardware dirty bit management is not enabled. (authored by markj). · Explain WhyAug 1 2019, 10:48 PM

This revision was automatically updated to reflect the committed changes.

markj added a commit: rS350525: Use ATTR_DBM even when hardware dirty bit management is not enabled..

Herald added a subscriber: imp. · View Herald TranscriptAug 1 2019, 10:48 PM

Revision Contents
Changeset List

Path

Size

sys/

arm64/

pmap.c

14 lines

include/

pte.h

4 lines

Diff 60309

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sys/arm64/arm64/pmap.c