Re: Crash with old Windows on new CPU

* Christian Ullrich wrote:

> Backends (and possibly other processes) crash at the slightest
> provocation, such as "SELECT * FROM pg_stat_activity;" or VACUUM. The
> log says either "exception 0xC0000005" (segfault) or "exception
> 0xC000001D" (illegal instruction).
>
> The interesting reason: The old host had a Core-generation CPU, which
> does not support the AVX2 instruction set. The new one has a
> Haswell-generation one, and this one does. The EDB distribution of 9.4
> was built with the Visual Studio 2013 compiler, whose CRT (aka libc) has
> a bug where it uses AVX2 instructions if the *CPU* supports them, but
> does not care whether the *OS* does, and 2008 doesn't. That support was
> added in SP1 for 7/2008R2.

> I just tried it, and it appears to work. If there is any interest in
> fixing this, I'll be happy to prepare a patch. (Where would be the best
> place to put a function call from <math.h> that has to be done during
> startup of each server process, on Windows only?)

startup_hacks(), I think. Proposed patch attached.

--
Christian