Re: Can not build kernel on 1GB VM

From: Michael Wayne <freebsd07_at_wayne47.com>
Date: Sat, 14 May 2022 13:20:39 UTC
On Fri, May 13, 2022 at 01:25:11PM +0200, Wojciech Puchar wrote:
> >>>   sudo make buildkernel KERNCONF=ROUTING
> >>> the machine ran out of swap. with a bunch of messages like:
> >>>   Apr 15 12:11:26 g1 kernel: swap_pager: indefinite wait buffer: bufobj: 0, blkno: 240593, size: 4096
> >>>   Apr 15 12:11:35 g1 kernel: swap_pager: indefinite wait buffer: bufobj: 0, blkno: 236224, size: 16384
> >>>   Apr 15 12:11:37 g1 kernel: swap_pager: indefinite wait buffer: bufobj: 0, blkno: 245, size: 12288
> >>>   Apr 15 12:11:46 g1 kernel: swap_pager: indefinite wait buffer: bufobj: 0, blkno: 240593, size: 4096
> >>>   Apr 15 12:11:55 g1 kernel: swap_pager: indefinite wait buffer: bufobj: 0, blkno: 236224, size: 16384
> >>>   Apr 15 12:11:57 g1 kernel: swap_pager: indefinite wait buffer: bufobj: 0, blkno: 245, size: 12288
> 
> i was getting such message when i used crappy SSD that stalled for very 
> long after receiving bunch of TRIM command from UFS filesystem and in the 
> same time OS did some swapping.

I had the provider check the SSD and got this back:

   We see no issues present on the host at this time. I suspect you
   may be experiencing the effects of a noisy neighbor or swap is
   coming into play.

> If you get out of swap, some processes (usually the largest) are killed. 
> And different messages are in log.

Those messsages are on the screen.

The machine >thinks< it's running out of swap:

May  9 13:05:57 g1 kernel: pid 9507 (ctfmerge), jid 0, uid 0, was killed: out of swap space
May  9 13:05:58 g1 kernel: pid 4969 (make), jid 0, uid 0, was killed: out of swap space
May  9 13:06:00 g1 kernel: pid 828 (openvpn), jid 0, uid 301, was killed: out of swap space
May  9 13:06:00 g1 kernel: tun0: link state changed to DOWN
May  9 13:06:01 g1 kernel: pid 889 (sendmail), jid 0, uid 0, was killed: out of swap space
May  9 13:06:03 g1 kernel: pid 909 (tcsh), jid 0, uid 5147, was killed: out of swap space
May  9 13:06:05 g1 kernel: pid 1091 (tcsh), jid 0, uid 5147, was killed: out of swap space
May  9 13:06:06 g1 kernel: pid 892 (sendmail), jid 0, uid 25, was killed: out of swap space
May  9 13:06:08 g1 kernel: pid 814 (ntpd), jid 0, uid 0, was killed: out of swap space
May  9 13:06:09 g1 kernel: pid 881 (bird), jid 0, uid 0, was killed: out of swap space
May  9 13:06:10 g1 kernel: pid 532 (devd), jid 0, uid 0, was killed: out of swap space
May  9 13:06:11 g1 kernel: pid 526 (dhclient), jid 0, uid 65, was killed: out of swap space
May  9 13:06:12 g1 kernel: pid 474 (dhclient), jid 0, uid 0, was killed: out of swap space
May  9 13:06:14 g1 kernel: pid 903 (getty), jid 0, uid 0, was killed: out of swap space