On Mon, 15 Mar 2021 at 14:58, Kevin Oberman <[email protected]> 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 _______________________________________________ [email protected] mailing list https://lists.freebsd.org/mailman/listinfo/freebsd-stable To unsubscribe, send any mail to "[email protected]"
