Filesystem operations slower in 13.0 than 12.2

[Kevin Oberman]

On Mon, Mar 22, 2021 at 8:19 AM Adrian Chadd <adrian.chadd at gmail.com> wrote:

> On Mon, 15 Mar 2021 at 14:58, Kevin Oberman <rkoberman at gmail.com> wrote:
>
> > >
> > > It appears that the messages are associated with reading
> > > the disk(s), not directly with writing them, where the
> > > reads take more than "hz * 20" time units to complete.
> > > (I'm looking at main (14) code.) What might contribute
> > > to the time taken for the pending read(s)?
> > >
> > The reference to hz * 20 woke up a few sleeping memory cells. I forgot
> that
> > I cleaned up my loader.conf. It was largely a copy of the one on my
> > decade-old T520. I commented out "kern.hz=100". I don't recall the
> details,
> > but I think it was actually from an even older system, my T42 from
> before I
> > retired.
> >
> > In any case, restoring this setting has greatly improved the situation. I
> > now have really bad disk I/O performance on large disk to disk activity
> > (untarring the firefox distro) instead of terrible performance and the
> > system freezes have vanished, though I do see pauses in response to
> clicks
> > or text entry, but the display remains active and the pauses are
> short... 1
> > to 15 seconds, I'd guess. No, I have no idea what this indicates.
>
> ... which drive controller is this? Is it just a laptop ATA disk?
>
> > I'm still not seeing the performance I was seeing back in February when
> 40
> > MB/s for extended intervals was common and I once untarred
> firefox.tar.gz2
> > in under a minute and performance seldom dropped below 1.4 MB/s.
>
> Did you find a resolution?  I wonder if setting kern.hz is kicking
> some process(es) to get some time more frequently due to bugs
> elsewhere in the system (interrupts, IPI handling, wake-ups, etc)
>
>
>
> -adrian
>
No resolution. This is a Lenovo L15 ThinkPad with a 2TB ATAPI drive. The
current drive is a Seagate.  All testing has been done since I got it back
from Lenovo in late January. I can read or write the drive at reasonable
rates that exceed 50 MB/s. Extracting a tar distribution file is painful. I
have had firefox extracts take over a half hour. Worse, if I do other
operations while the extract is taking place, I often see a 30 second (and,
occasionally 60 second) display freezes as well as log reports that of
"swap_pager: indefinite wait buffer:" This is a bit odd as I have 20G of
RAM and am pretty close to no swap space activity, but, of course, paging
does occur.

This system is CometLake and graphics are not supported on 12. I am not
absolutely sure that there is not a hardware issue even though the main
board, the disk, and the keyboard/mouse pad have all been replace since I
received the system back last June. I now wonder what else could go wrong.
--
Kevin Oberman, Part time kid herder and retired Network Engineer
E-mail: rkoberman at gmail.com
PGP Fingerprint: D03FB98AFA78E3B78C1694B318AB39EF1B055683