On 2021-Mar-22, at 22:51, Kevin Oberman <rkoberman at gmail.com> wrote:
> On Mon, Mar 22, 2021 at 8:19 AM Adrian Chadd <adrian.ch...@gmail.com> wrote: >> On Mon, 15 Mar 2021 at 14:58, Kevin Oberman <rkober...@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. I've not found documentation indicating the "which drive controller" answer. That may have to be answered from boot messages or boot -v messages or other such on FreeBSD. (I've no access to such a machine.) You might want to put a copy of such a log someplace that folks could look at it. There may be commands that some folks would like to see the output of. (I'm not all that likely to be one that could put such to use but other folks might be able to.) Intel® Celeron®? 10th Generation Intel CoreTM i3? i5? i7? > 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 I thought that you had reported that use of kern.hz=100 had lead to "the system freezes have vanished" and "pauses are short... 1 to 15 seconds". Did more testing show that to not be always the case? > as well as log reports that of "swap_pager: indefinite wait buffer:" Unfortunately, I do not know how to investigate what is leading to those message being generated. Figuring that out would seem to be important but I do not know what to monitor to at least potentially eliminate some possibilities. One possible thing to look at is something like "gstat -spod" output spanning the time of the untar. It would at least indicate if a large queue backlog was accumulating on the device. And the ms/r and ms/w columns would give a clue if commands are sitting in the queues for long periods. (The "d" may be a waste: no BIO_DELETEs possible? Also, the r/s vs. ms/r are not rescaled reciprocals but distinct measurements. Similarly for: the w/s vs. ms/w.) Given the "indefinite wait buffer" messages, I expect the ms/r and/or ms/w figures to be large at least some of the time. Knowing how large may be of use to someone. But I can not eliminate anything with such information. > 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. With 20 GiBytes of RAM, what is going on at the time that leads to paging activity? I'm thinking of just untarring the firefox file, not building firefox or such. Can you test such an untar in a context that is not otherwise paging (nor swapping)? If yes, is the behavior different in any readily noticeable way? > 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. === Mark Millard marklmi at yahoo.com ( dsl-only.net went away in early 2018-Mar) _______________________________________________ freebsd-stable@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/freebsd-stable To unsubscribe, send any mail to "freebsd-stable-unsubscr...@freebsd.org"
