Re: poudriere: swap_pager: out of swap space

On Thu, 11 Jan 2024 02:21:19 +0000
Lexi Winter <lexi@le-fay.org> wrote:

> hi list,
> 
> i'm having a recurring problem with poudriere that i hope someone might
> have an idea about.
> 
> i'm building packages with poudriere on a system with 32GB memory, with
> tmpfs and md disabled in poudriere (so it's using ZFS only) and with the
> ZFS ARC limited to 8GB.
> 
> running poudriere produces many kernel log messages like this:
> 
> Jan 10 21:40:00 ilythia kernel: swap_pager: out of swap space
> Jan 10 21:40:00 ilythia kernel: swp_pager_getswapspace(2): failed
> Jan 10 22:41:55 ilythia kernel: swap_pager: out of swap space
> Jan 10 22:41:55 ilythia kernel: swp_pager_getswapspace(21): failed
> Jan 10 23:48:03 ilythia kernel: swap_pager: out of swap space
> Jan 10 23:48:03 ilythia kernel: swp_pager_getswapspace(8): failed
> Jan 11 00:05:00 ilythia kernel: swp_pager_getswapspace(1): failed
> Jan 11 00:21:45 ilythia kernel: swp_pager_getswapspace(10): failed
> 
> this is despite the system having a large amount of "Inact" memory
> according to top(1):
> 
> Mem: 3828M Active, 15G Inact, 2921M Laundry, 9263M Wired, 1559M Buf, 892M Free
> ARC: 3113M Total, 994M MFU, 884M MRU, 39M Anon, 49M Header, 1139M Other
>      1296M Compressed, 4130M Uncompressed, 3.19:1 Ratio
> Swap: 2048M Total, 2048M Used, 8192B Free, 99% Inuse
> 
> from what i can tell, these swap errors don't cause any issues with the
> poudriere build, but they do seem to hinder interactive usage by causing
> long hangs.
> 
> does anyone have some idea what's going on here?  i don't really
> understand why the system has used 100% of available swap space when it
> has plenty of Inact memory it could free to fulfill requirements.

I'm currently building www/chromium, consuming 23.1GiB of memory and
11.4GiB of swap in use. 32GiB of physical memory but not intentionally
limiting ZFS arc.

If you don't build such a large ports, you could lower the number of
poudriere jail with option -J, for example, from auto-tuned value to
reduce memory usage.

FYI:
When chromium built around 87%, with USE_TMPFS=yes.

172 processes: 16 running, 156 sleeping
CPU: 91.2% user,  1.5% nice,  6.7% system,  0.6% interrupt,  0.0% idle
Mem: 13G Active, 1670M Inact, 6499M Laundry, 6985M Wired, 347K Buf,
3490M Free ARC: 3183M Total, 393M MFU, 2102M MRU, 2980K Anon, 34M
Header, 643M Other 1826M Compressed, 3471M Uncompressed, 1.90:1 Ratio
Swap: 64G Total, 12G Used, 53G Free, 18% Inuse


-- 
Tomoaki AOKI    <junchoon@dec.sakura.ne.jp>