Re: OpenBSD 7.2 on Alpha

Here is the output of the commands:

ddb> x/lx cpu_amask
cpu_amask:                 0
ddb> x/i __bwx_switch0,3
__bwx_switch0:  lda     t0,7(zero)
__bwx_switch0+0x4:      stb     t0,95(s2)
__bwx_switch0+0x8:      ldq     v0,-7b88(gp)


----- Original Message -----
From: "Miod Vallat" <[email protected]>
To: "Mark Butt" <[email protected]>
Cc: "alpha" <[email protected]>
Sent: Monday, January 2, 2023 2:59:46 PM
Subject: Re: OpenBSD 7.2 on Alpha

Thank you for this boot log.

At the "ddb>" prompt, can you tell me the output of the following two
commands:

  x/lx cpu_amask
  x/i __bwx_switch0,3

I believe that the kernel has incorrectly decided to enable a faster
code path in the process switching code, relying upon instruction
extensions which your processors do not support. Those two ddb commands
would confirm this (and also, this would explain why the installation
kernel is not affected, as it does not contain this optimization).