Re: bin/55721: usr.sbin/cpuctl/t_cpuctl:nointr, offline tests fail

[Rin Okuyama <rokuyama.rk%gmail.com@localhost>]

The following reply was made to PR bin/55721; it has been noted by GNATS.

From: Rin Okuyama <rokuyama.rk%gmail.com@localhost>
To: Andreas Gustafsson <gson%gson.org@localhost>
Cc: gnats-bugs%netbsd.org@localhost
Subject: Re: bin/55721: usr.sbin/cpuctl/t_cpuctl:nointr, offline tests fail
Date: Mon, 12 Oct 2020 17:24:37 +0900

 This is due to mine:
 
 http://www.nerv.org/netbsd/?q=id:20201008T091613Z.7bca1a7879657c09b2d6976a827a557446ab4627
 
 I doubt whether these tests are correct.
 
 As wrote in the commit log, we had ignored any errors when enabling or
 disabling interrupts for a CPU core by IOC_CPU_SETSTATE ioctl, until
 kern_cpu.c rev 1.91. This behavior was changed in rev 1.92; if
 enabling/disabling interrupts fails, the ioctl breaks there, and does
 not try to make that core online/offline. The newly failing tests
 depend on this behavior. However, this change resulted in regression
 described in the commit log.
 
 Yes, the current behavior of the ioctl is unclear. However, IMO, this
 is limitation of design of IOC_CPU_SETSTATE ioctl itself; both of
 whether intr/nointr and online/offline should be specified to a CPU
 core, and you cannot set one of them.
 
 Also, comment in the test says:
 
 https://nxr.netbsd.org/xref/src/tests/usr.sbin/cpuctl/t_cpuctl.sh#184
      184 	# Additional check that the boot processor cannot be
      185 	# set offline, as noted in the cpuctl(8) manual page.
 
 But there's no such explanation in cpuctl(8).
 
 Thanks,
 rin