Detect number of cores better on multi-socket systems#6108
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rimrul wants to merge 2 commits intogit-for-windows:mainfrom
Open
Detect number of cores better on multi-socket systems#6108rimrul wants to merge 2 commits intogit-for-windows:mainfrom
rimrul wants to merge 2 commits intogit-for-windows:mainfrom
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Git for Windows doesn't support anything prior to Windows 8.1 since 2.47.0 and Git followed along with commits like ce6ccba (mingw: drop Windows 7-specific work-around, 2025-08-04). There is no need to pretend to the compiler that we still support Windows Vista, just to lock us out of easy access to newer APIs. There is also no need to have conflicting and unused definitions claiming we support some versions of Windows XP or even Windows NT 4.0. Bump all definitions of _WIN32_WINNT to a realistic value of Windows 8.1. This will also simplify code for a followup commit that will improve cpu core detection on multi-socket systems. Signed-off-by: Matthias Aßhauer <mha1993@live.de>
While the currently used way to detect the number of CPU cores on Windows is nice and straight-forward, GetSystemInfo() only gives us access to the number of processors within the current group. [1] While that is usually fine for systems with a single physical CPU, separate physical sockets are typically separate groups. Switch to using GetLogicalProcessorInformationEx() to handle multi-socket systems better. [1] https://learn.microsoft.com/en-us/windows/win32/api/sysinfoapi/ns-sysinfoapi-system_info#members This fixes git-for-windows#4766 Co-Authored-by: Herman Semenov <GermanAizek@yandex.ru> Signed-off-by: Matthias Aßhauer <mha1993@live.de>
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Nice! I have no way of testing this, that's why it's extra nice that you can confirm that this works as advertised.
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While the currently used way to detect the number of CPU cores ond
Windows is nice and straight-forward, GetSystemInfo() only gives us
access to the number of processors within the current group.
While that is usually fine for systems with a single physical CPU,
separate physical sockets are typically separate groups.
Switch to using GetLogicalProcessorInformationEx() to handle multi-socket
systems better.
I've tested this on a physical single-socket x86-64 and a physical dual-socket x86-64 system, and on a virtual single-socket ARM64 system. Physical multi-socket ARM64 systems seem to exist, but I don't have access to such hardware and the hypervisor I use apparently can't emulate that either.