Date: Sun, 5 Jun 2022 15:04:22 -0700 From: Mark Millard <marklmi@yahoo.com> To: FreeBSD Hackers <freebsd-hackers@freebsd.org> Subject: Re: What can I learn about data that is staying paged out? (There is a more specific poudriere bulk related context given.) Message-ID: <A9C9AC24-62EC-43C1-B713-F2012CD1FD5B@yahoo.com> In-Reply-To: <C337A09C-D546-46FC-A166-DBB3237D1AFC@yahoo.com> References: <C337A09C-D546-46FC-A166-DBB3237D1AFC@yahoo.com>
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On 2022-Jun-5, at 12:42, Mark Millard <marklmi@yahoo.com> wrote:
> I have a poudriere bulk -a -c going on a 8 Gibyte
> aarch64 system. top has been showing an occasionally
> increasing swap usage but never any sizable decreases.
> Over 5800 ports have built so far. The context is UFS
> only. The system is running a non-debug build of main.
>=20
> Part of the context is ( in /etc/sysctl.conf ):
>=20
> vm.swap_enabled=3D0
> vm.swap_idle_enabled=3D0
>=20
> Also ( in /usr/local/etc/poudriere.conf ):
>=20
> USE_TMPFS=3D"data"
>=20
> poudriere's TMPFS reports normally total under 128
> KiBytes across the 4 builders.
>=20
> For reference, example figures . . .
>=20
> A top variant shows:
>=20
> Swap: 30720Mi Total, 306816Ki Used
>=20
> vmstat -s shows:
>=20
> 78152 swap pager pages paged out
>=20
> Note: (78152*4096)/1024 =3D=3D 312608Ki
>=20
> So nearly all of the "swap pager pages paged out"
> pages are still sitting out in the used swap/paging
> space. Thus, the usage is not held by user processes
> or is held via very long running processes or is
> not directly tied to user processes --or some mix.
>=20
> The variant of top reports never having observed
> more than: 6658Mi MaxObs(Act+Wir+Lndry).
> ("MaxObs" is short for "Maximum Observed".)
> Such high usage is for a bounded time, long past
> at this point. (Until some combination of port
> builds ends up active that uses such.)
>=20
> So I'm curious:
>=20
> What can I learn about the data that is staying
> paged out (and is gradually growing)? How can I
> learn it?
>=20
>=20
> Other notes:
>=20
> The poudriere jail being built is:
>=20
> # poudriere jail -jmain-CA7-bulk_a -i
> Jail name: main-CA7-bulk_a
> Jail version: 14.0-CURRENT
> Jail arch: arm.armv7
> Jail method: null
> Jail mount: /usr/obj/DESTDIRs/main-CA7-poud-bulk_a
> Jail fs: =20
> Jail updated: 2022-05-23 02:21:24
> Jail pkgbase: disabled
>=20
> (Just in case the armv7 jail usage or the null method
> or such is important to the issue.)
Hmm. systat -swap reports a toal for the Devices/Paths Used
that is somewhat less than the total for what reports for the
Pid . . . Total figures (not the Pid Swap figures!):
# systat -swap
/0 /1 /2 /3 /4 /5 /6 /7 /8 /9 =
/10
Load Average |||||||| =20
Device/Path Size Used |0% /10 /20 /30 /40 / 60\ 70\ 80\ =
90\ 100|
gpt/CA72USBswp14 14G 150M
gpt/CA72USBswp16 16G 150M
Total 30G 300M
Pid Username Command Swap/Total Per-Process Per-System
1453 root nfsd 1M / 15M 9% 0%
1451 root mountd 1M / 15M 7% 0%
1481 root sshd 912K / 20M 4% 0%
1406 root ntpd 740K / 27M 2% 0%
1513 root login 724K / 14M 5% 0%
1514 root sh 656K / 13M 4% 0%
342 _dhcp dhclient 516K / 13M 3% 0%
1363 root rpcbind 448K / 13M 3% 0%
1454 root nfsd 400K / 12M 3% 0%
341 root dhclient 380K / 13M 2% 0%
1341 root syslogd 324K / 12M 2% 0%
1505 root getty 292K / 12M 2% 0%
1510 root getty 292K / 12M 2% 0%
1511 root getty 292K / 12M 2% 0%
1512 root getty 292K / 12M 2% 0%
1509 root getty 292K / 12M 2% 0%
1508 root getty 292K / 12M 2% 0%
1507 root getty 292K / 12M 2% 0%
1506 root getty 288K / 12M 2% 0%
1135 root devd 272K / 11M 2% 0%
338 root dhclient 264K / 13M 2% 0%
1 root init 244K / 11M 2% 0%
1486 root cron 188K / 13M 1% 0%
I'm, Still looking for a clear indication of what
most of the 300 MiBytes or so of swap/paging space
is in use for.
=3D=3D=3D
Mark Millard
marklmi at yahoo.com
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