In message <CAN6yY1tioVfhnEu0eEyE4wROJ5bJ3an2rOYM95cj1d44CTiJew_at_mail.gmail.c om> , Kevin Oberman writes: > --089e01176a5d71db0d052f8803c7 > Content-Type: text/plain; charset=UTF-8 > > On Sat, Apr 2, 2016 at 2:19 PM, O. Hartmann <ohartman_at_zedat.fu-berlin.de> > wrote: > > > Am Sat, 2 Apr 2016 11:39:10 +0200 > > "O. Hartmann" <ohartman_at_zedat.fu-berlin.de> schrieb: > > > > > Am Sat, 2 Apr 2016 10:55:03 +0200 > > > "O. Hartmann" <ohartman_at_zedat.fu-berlin.de> schrieb: > > > > > > > Am Sat, 02 Apr 2016 01:07:55 -0700 > > > > Cy Schubert <Cy.Schubert_at_komquats.com> schrieb: > > > > > > > > > In message <56F6C6B0.6010103_at_protected-networks.net>, Michael > > Butler writes: > > > > > > -current is not great for interactive use at all. The strategy of > > > > > > pre-emptively dropping idle processes to swap is hurting .. big > > time. > > > > > > > > > > FreeBSD doesn't "preemptively" or arbitrarily push pages out to > > disk. LRU > > > > > doesn't do this. > > > > > > > > > > > > > > > > > Compare inactive memory to swap in this example .. > > > > > > > > > > > > 110 processes: 1 running, 108 sleeping, 1 zombie > > > > > > CPU: 1.2% user, 0.0% nice, 4.3% system, 0.0% interrupt, 94.5% > > idle > > > > > > Mem: 474M Active, 1609M Inact, 764M Wired, 281M Buf, 119M Free > > > > > > Swap: 4096M Total, 917M Used, 3178M Free, 22% Inuse > > > > > > > > > > To analyze this you need to capture vmstat output. You'll see the > > free pool > > > > > dip below a threshold and pages go out to disk in response. If you > > have > > > > > daemons with small working sets, pages that are not part of the > > working > > > > > sets for daemons or applications will eventually be paged out. This > > is not > > > > > a bad thing. In your example above, the 281 MB of UFS buffers are > > more > > > > > active than the 917 MB paged out. If it's paged out and never used > > again, > > > > > then it doesn't hurt. However the 281 MB of buffers saves you I/O. > > The > > > > > inactive pages are part of your free pool that were active at one > > time but > > > > > now are not. They may be reclaimed and if they are, you've just > > saved more > > > > > I/O. > > > > > > > > > > Top is a poor tool to analyze memory use. Vmstat is the better tool > > to help > > > > > understand memory use. Inactive memory isn't a bad thing per se. > > Monitor > > > > > page outs, scan rate and page reclaims. > > > > > > > > > > > > > > > > > > I give up! Tried to check via ssh/vmstat what is going on. Last lines > > before broken > > > > pipe: > > > > > > > > [...] > > > > procs memory page disks faults > > cpu > > > > r b w avm fre flt re pi po fr sr ad0 ad1 in sy cs > > us sy id > > > > 22 0 22 5.8G 1.0G 46319 0 0 0 55721 1297 0 4 219 23907 > > 5400 95 5 0 > > > > 22 0 22 5.4G 1.3G 51733 0 0 0 72436 1162 0 0 108 40869 > > 3459 93 7 0 > > > > 15 0 22 12G 1.2G 54400 0 27 0 52188 1160 0 42 148 52192 > > 4366 91 9 0 > > > > 14 0 22 12G 1.0G 44954 0 37 0 37550 1179 0 39 141 86209 > > 4368 88 12 0 > > > > 26 0 22 12G 1.1G 60258 0 81 0 69459 1119 0 27 123 779569 > > 704359 87 13 0 > > > > 29 3 22 13G 774M 50576 0 68 0 32204 1304 0 2 102 507337 > > 484861 93 7 0 > > > > 27 0 22 13G 937M 47477 0 48 0 59458 1264 3 2 112 68131 > > 44407 95 5 0 > > > > 36 0 22 13G 829M 83164 0 2 0 82575 1225 1 0 126 99366 > > 38060 89 11 0 > > > > 35 0 22 6.2G 1.1G 98803 0 13 0 121375 1217 2 8 112 99371 > > 4999 85 15 0 > > > > 34 0 22 13G 723M 54436 0 20 0 36952 1276 0 17 153 29142 > > 4431 95 5 0 > > > > Fssh_packet_write_wait: Connection to 192.168.0.1 port 22: Broken pipe > > > > > > > > > > > > This makes this crap system completely unusable. The server (FreeBSD > > 11.0-CURRENT #20 > > > > r297503: Sat Apr 2 09:02:41 CEST 2016 amd64) in question did > > poudriere bulk job. I > > > > can not even determine what terminal goes down first - another one, > > much more time > > > > idle than the one shwoing the "vmstat 5" output, is still alive! > > > > > > > > i consider this a serious bug and it is no benefit what happened since > > this "fancy" > > > > update. :-( > > > > > > By the way - it might be of interest and some hint. > > > > > > One of my boxes is acting as server and gateway. It utilises NAT, IPFW, > > when it is under > > > high load, as it was today, sometimes passing the network flow from ISP > > into the network > > > for clients is extremely slow. I do not consider this the reason for > > collapsing ssh > > > sessions, since this incident happens also under no-load, but in the > > overall-view onto > > > the problem, this could be a hint - I hope. > > > > I just checked on one box, that "broke pipe" very quickly after I started > > poudriere, > > while it did well a couple of hours before until the pipe broke. It seems > > it's load > > dependend when the ssh session gets wrecked, but more important, after the > > long-haul > > poudriere run, I rebooted the box and tried again with the mentioned > > broken pipe after a > > couple of minutes after poudriere ran. Then I left the box for several > > hours and logged > > in again and checked the swap. Although there was for hours no load or > > other pressure, > > there were 31% of of swap used - still (box has 16 GB of RAM and is > > propelled by a XEON > > E3-1245 V2). > > > > Unless something has changed, just as things are not preemptively swapped > out, they are also not preemptively swapped back in. AFAIK, once a process > is swapped out, it will remain swapped out until/unless it becomes active. > At that time it is swapped in and this can entail a significant delay. If > my laptop is locked and something (usually Chromium) starts eating all of > the memory and processes start swapping out, it can take >5 seconds to get > the unlock window to display. Yes! -- Cheers, Cy Schubert <Cy.Schubert_at_komquats.com> or <Cy.Schubert_at_cschubert.com> FreeBSD UNIX: <cy_at_FreeBSD.org> Web: http://www.FreeBSD.org The need of the many outweighs the greed of the few.Received on Sat Apr 02 2016 - 20:57:58 UTC
This archive was generated by hypermail 2.4.0 : Wed May 19 2021 - 11:41:03 UTC