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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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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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Event Timeline

markj created this revision.Jul 30 2019, 8:20 PM
alc added a comment.Jul 30 2019, 10:17 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

alc added a comment.Jul 31 2019, 6:28 AM

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