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items: mem limit does not work... ?
items: Re: mem limit does not work... ?

mem limit does not work... ?
type: item
description: Hello! I've set a RAM Limit to 128MB - but the VPS can consume 2GB without any problems... that can't be right or? I also have the following messages in syslog: Uncharging too much 1 h 0, res unused_privvmpages ub 4 Uncharging too much 262218 h 218587, res unused_privvmpages ub 4 Uncharging too much 2 h 0, res unused_privvmpages ub 4 Anybody here who has an idea? Stefan cat /proc/user_beancounters Version: 2.5 uid resource held maxheld barrier limit failcnt 4: kmemsize 434569 1484885 2752512 2936012 0 lockedpages 0 0 32 32 0 privvmpages 3910 263944 49152 53575 16 shmpages 640 656 8192 8192 0 dummy 0 0 0 0 0 numproc 7 10 65 65 0 physpages 944 263305 134217728 134217728 0 vmguarpages 0 0 134217728 134217728 0 oomguarpages 944 263305 134217728 134217728 0 numtcpsock 2 2 80 80 0 numflock 1 2 100 110 0 numpty 1 1 16 16 0 numsiginfo 0 6 256 256 0 tcpsndbuf 2224 8896 319488 524288 0 tcprcvbuf 0 8544 319488 524288 0 othersockbuf 2224 7200 132096 336896 0 dgramrcvbuf 0 4272 132096 132096 0 numothersock 1 6 80 80 0 dcachesize 91840 95858 1048576 1097728 0 numfile 86 111 2048 2048 0 dummy 0 0 0 0 0 dummy 0 0 0 0 0 dummy 0 0 0 0 0 numiptent 4 4 128 128 0
creator: disaster
date: 2006-02-18T10:51:29-00:00

Re: mem limit does not work... ?
type: item
description: All the parameters which have "pages" in their names are configured in pages... So you set 4096*128Mb limits... it is much more than 2GB We will add simple ability to specify UBC parameters in any units in vzctl soon, so e.g. you will be able to do --vmguarpages 128m.
creator: dev
date: 2006-02-19T07:27:28-00:00

Re: mem limit does not work... ?
type: item
description: Thanks for your reply - so if i want to set a limit to 128M i have now tried - the following: 128M*1024*1024 => 134217728 bytes / 4096 => 32768 and then i used: vzctl set 4 --privvmpages 32768:32768 --oomguarpages 32768:32768 --physpages 32768:32768 --vmguarpages 32768:32768 --save but it dos not work... i can still allocate 2GB... Another question: Is there a listing for the meaning of privvmpages, vmguarpages, numpty, numproc etc. ? Stefan
creator: disaster
date: 2006-02-19T09:11:53-00:00

Re: mem limit does not work... ?
type: item
description: OK - i found some strange things... 1. i can still allocate 1GB and more 2. a cat cat /proc/user_beancounters shows me failures at privvmpages failcnt=4 - but the script can work and is not killed 3. on the host machine i see in syslog: Uncharging too much 1 h 0, res unused_privvmpages ub 4 Uncharging too much 1 h 0, res unused_privvmpages ub 4 Uncharging too much 1 h 0, res unused_privvmpages ub 4 Uncharging too much 1 h 0, res unused_privvmpages ub 4 Uncharging too much 1 h 0, res unused_privvmpages ub 4 Uncharging too much 1 h 0, res unused_privvmpages ub 4 Uncharging too much 1 h 0, res unused_privvmpages ub 4 Uncharging too much 1 h 0, res unused_privvmpages ub 4 Uncharging too much 1 h 0, res unused_privvmpages ub 4 Fatal resource shortage: kmemsize, UB 4. Uncharging too much 65610 h 54827, res unused_privvmpages ub 4 Uncharging too much 3 h 0, res unused_privvmpages ub 4 What does that mean? 4. if i set kmemsize to 655360 the script can only allocate 128MB Any idea?
creator: disaster
date: 2006-02-19T09:46:27-00:00

Re: mem limit does not work... ?
type: item
description: 1. can you please provide /proc/user_beancounters and a script?... 2. failct=4 and messages like: Fatal resource shortage: kmemsize, UB 4. mean that you hit kmemsize limit 4 times. Applications are not killed in these cases. Usually syscalls simply return ENOMEM and most applications handle errors gracefully. 3. messages like: Uncharging too much 1 h 0, res unused_privvmpages ub 4 mean that there is some discrepancy in privvmpages accounting. This is why I would be happy to your script which reproduces this problem. 4. kmemsize has nothing to do with app memory. So to answer your questions quickly it would be helpfull to get your script and exact examples/steps you used and wonder about their results.
creator: dev
date: 2006-02-19T09:57:39-00:00

Re: mem limit does not work... ?
type: item
description: Quote: 1. can you please provide /proc/user_beancounters and a script?... No Problem - here are the details: user_beancounters before script: cat /proc/user_beancounters Version: 2.5 uid resource held maxheld barrier limit failcnt 4: kmemsize 434432 477994 13107200 13107200 0 lockedpages 0 0 32 32 0 privvmpages 3915 5868 32768 32768 0 shmpages 640 656 8192 8192 0 dummy 0 0 0 0 0 numproc 7 8 65 65 0 physpages 945 945 32768 32768 0 vmguarpages 0 0 32768 32768 0 oomguarpages 945 945 32768 32768 0 numtcpsock 2 2 80 80 0 numflock 1 2 100 110 0 numpty 1 1 16 16 0 numsiginfo 0 1 256 256 0 tcpsndbuf 2224 8896 319488 524288 0 tcprcvbuf 0 4272 319488 524288 0 othersockbuf 2224 7200 132096 336896 0 dgramrcvbuf 0 4272 132096 132096 0 numothersock 1 5 80 80 0 dcachesize 91840 94136 1048576 1097728 0 numfile 86 90 2048 2048 0 dummy 0 0 0 0 0 dummy 0 0 0 0 0 dummy 0 0 0 0 0 numiptent 4 4 128 128 0 My Script - you don't like... and this time with top output perl -e '$a="a";for(;;) {$a.=$a; print "allocated ".int(length($a)/1024/1024)."MB\n";}' allocated 0MB allocated 0MB allocated 0MB allocated 0MB allocated 0MB allocated 0MB allocated 0MB allocated 0MB allocated 0MB allocated 0MB allocated 0MB allocated 0MB allocated 0MB allocated 0MB allocated 0MB allocated 0MB allocated 0MB allocated 0MB allocated 0MB allocated 1MB allocated 2MB allocated 4MB allocated 8MB allocated 16MB allocated 32MB allocated 64MB allocated 128MB allocated 256MB allocated 512MB allocated 1024MB Out of memory! Top Output Mem: 2071904k total, 1067136k used, 1004768k free, 10272k buffers Swap: 1437776k total, 0k used, 1437776k free, 46148k cached PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ Command 4544 root 25 0 1027m 878m 2576 R 94.0 43.4 0:09.74 perl As you can see, there is a total of 1GB RAM and perl eats 43% which is about 800MB the res 200MB are used from normal system. user_beancounters after script start cat /proc/user_beancounters Version: 2.5 uid resource held maxheld barrier limit failcnt 4: kmemsiz…
creator: disaster
date: 2006-02-19T10:26:10-00:00

Re: mem limit does not work... ?
type: item
description: I've now tested Kernel 2.6.15 with the beta Patch - there it WORKS!!! I'm not able to allocate more that 115MB with perl - but the fairscheduler does not work So i think we must wait for fairscheduler 2.6.15 or for a patch for 2.6.8 ... Stefan
creator: disaster
date: 2006-02-19T13:07:28-00:00

Re: mem limit does not work... ?
type: item
description: Don't worry, I will check it soon and will return back to you.
creator: dev
date: 2006-02-19T17:56:25-00:00

Re: mem limit does not work... ?
type: item
description: I filled in bug #104 (http://bugzilla.openvz.org/show_bug.cgi?id=104) The patch is attached inside. New kernel will be released soon. Thanks a lot for reporting this!
creator: dev
date: 2006-02-20T10:23:38-00:00

Re: mem limit does not work... ?
type: item
description: Thanks a lot! I will patch the kernel and will try it again. Also i will test some other things the next days. If i find some other things - i'll report this.
creator: disaster
date: 2006-02-20T10:29:42-00:00

Re: mem limit does not work... ?
type: item
description: Thanks for solving this bug! The patch works fine on my system.
creator: atomic
date: 2006-02-20T10:45:54-00:00