Re: port-evbarm/56944: ZFS heavy usage on NetBSD running in Mac M1 VM results in kernel thread running away and filesystem hang

[Brad Spencer <brad%anduin.eldar.org@localhost>]

The following reply was made to PR port-evbarm/56944; it has been noted by GNATS.

From: Brad Spencer <brad%anduin.eldar.org@localhost>
To: chuq%chuq.com@localhost, gnats-bugs%netbsd.org@localhost
Cc: port-evbarm-maintainer%netbsd.org@localhost, gnats-admin%netbsd.org@localhost,
        netbsd-bugs%netbsd.org@localhost, pjledge%me.com@localhost
Subject: Re: port-evbarm/56944: ZFS heavy usage on NetBSD running in Mac M1
 VM results in kernel thread running away and filesystem hang
Date: Sat, 30 Jul 2022 09:45:03 -0400

 Chuck Silvers <chuq%chuq.com@localhost> writes:
 
 > The following reply was made to PR port-evbarm/56944; it has been noted by GNATS.
 >
 > From: Chuck Silvers <chuq%chuq.com@localhost>
 > To: gnats-bugs%netbsd.org@localhost
 
 [snip]
 
 >  oh, you've got a zvol as swap space.  that has never worked on netbsd
 >  and it's not going to work for the foreseeable future.  using a zfs file
 >  as a swap file will also hang eventually.  you'll need to change your setup
 >  to have the swap space be something that doesn't involve zfs.
 >  
 >  -Chuck
 >  
 
 
 Ya, that was another test.  In 9.x you could not even attempt to do that
 as the ioctls are missing, but in -current the attempt will succeed.  I
 reconfigured the guest to use another presented virtual disk and am
 running the "zfs receive" test.  So far it is working without a hang,
 with many times the amount of data sent then before, but it will take a
 while to complete.  I have captured some vmstat -m output and noted that
 the system does swap a little while the operation is running.  I will
 post the info when it completes.
 
 
 -- 
 Brad Spencer - brad%anduin.eldar.org@localhost - KC8VKS - http://anduin.eldar.org