Horton

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  1. Re: [PATCH] Fix ARM64/MSVC atomic memory ordering issues on Win11 by adding explicit DMB ​barriers

    Greg Burd <greg@burd.me> — 2025-11-22T21:43:30Z

    Okay,

With the new MSVC compiler flag Andres mentioned (/arch:armv9.4) I only
had to update the S_UNLOCK() macro, the compiler did the rest correctly
AFAICT.  So, a much smaller patch (v2) attached. FWIW I'm using Visual
Studio 2026 (18) to build, other platform information below [1].

The white space/formatting issues seem to have been due to my ineptitude
on Windows running pgindent, or maybe I can blame Perl.  I'll try to dig
if I get a minute to figure out what was the cause and if I need to
patch something.

Also attached is a file with some notes on how I build. The build farm
section isn't finished yet, but there is value in the rest for anyone
doing similar work.  If you're wondering how I learned PowerShell, I
didn't.  I used AI, forgive me.  Eventually I'll have a build animal to
add to the "farm" and update a wiki page somewhere when this solidifies
a bit more. :)

best.

-greg

[1] OS Name	Microsoft Windows 11 Pro
Version	10.0.26100 Build 26100
Other OS Description 	Not Available
OS Manufacturer	Microsoft Corporation
System Name	SANTORINI
System Manufacturer	Microsoft Corporation
System Model	Windows Dev Kit 2023
System Type	ARM64-based PC
System SKU	2043
Processor	Snapdragon Compute Platform, 2995 Mhz, 8 Core(s), 8 Logical Processor(s)
BIOS Version/Date	Microsoft Corporation 13.42.235, 11/13/2024