Use Persistent Memory as storage for disk cache

[cukiernik]

Allows use the Intel Optane Persistent Memory as a storage for cache. It map storage directly into user space memory, so reads and writes are doing by a memcpy (without calls an io).

For configure use script tools/ipm-configure. It be need restart system probably, and run again. It configure PMem into AppDirect mode, and configure nemespaces to devdax mode. Data stored in them, be able after restart.

[cukiernik]

https://github.com/apache/trafficserver/issues/8693

[bryancall]

@SolidWallOfCode is going to review this

[bryancall]

@moonchen will review this

[cukiernik]

Can You help mi about RAT fail? It be ok, if I put Intel Open Source License into headers?

[bneradt]

Can You help mi about RAT fail? It be ok, if I put Intel Open Source License into headers?

It's just alerting that some of the new files do not have valid license headers:

• ./tools/ipm-configure
• ./tools/ipm-performance

You can just copy and paste the license from one of the other tools files into those files. For example:

https://github.com/apache/trafficserver/blob/1c038e512103c4c1b32e335c980f9fae51f45f9d/tools/build_h3_tools.sh#L6-L20

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Update

Oh, I see. This patch copies content from Intel. Hmmm...it looks like their copyright is a pretty open, BSD style license? I believe what we may want to do is copy both the Intel copyright and our Apache copyright into this file. @bryancall / @zwoop : do you know what the precedent is for such copies from other source code?

[moonchen]

This has been in draft for a while. Is it ready for review?

[bryancall]

[approve ci autest]

[ezelkow1]

[approve ci centos cmake]

[bryancall]

[approve ci]

[bryancall]

@cukiernik is this change relevant since Intel stopped supporting Optane?

[github-actions[bot]]

This pull request has been automatically marked as stale because it has not had recent activity. Marking it stale to flag it for further consideration by the community.