Am Sat, 2 Apr 2016 11:39:10 +0200 "O. Hartmann" <ohart...@zedat.fu-berlin.de> schrieb:
> Am Sat, 2 Apr 2016 10:55:03 +0200 > "O. Hartmann" <ohart...@zedat.fu-berlin.de> schrieb: > > > Am Sat, 02 Apr 2016 01:07:55 -0700 > > Cy Schubert <cy.schub...@komquats.com> schrieb: > > > > > In message <56f6c6b0.6010...@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).
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