Ubuntu LTS 16.04.2 uname -a Linux DESKTOP 4.4.0-63-generic #84-Ubuntu SMP Wed Feb 1 17:20:32 UTC 2017 x86_64 x86_64 x86_64 GNU/Linux Memory from top: KiB Mem : 16107416 total, 10167280 free, 3403820 used, 2536316 buff/cache KiB Swap: 0 total, 0 free, 0 used. 11914184 avail Mem
grep -v "^#" /etc/sysctl.conf net.core.rmem_max=16777216 net.core.wmem_max=16777216 net.ipv4.tcp_rmem="4096 87380 16777216" net.ipv4.tcp_wmem="4096 65536 16777216" net.ipv4.tcp_no_metrics_save=1 vm.swappiness = 5 vm.min_free_kbytes=65536 /etc$ cat lsb-release DISTRIB_ID=Ubuntu DISTRIB_RELEASE=16.04 DISTRIB_CODENAME=xenial DISTRIB_DESCRIPTION="Ubuntu 16.04.2 LTS" 100% repeatable freezing on high memory usage. Today test: 1. 3 vbox copies with 2Gb RAM. 2. tomcat, hornetq - with default settings. 3. firefox+thunderbird. 4. and final before freezing: started VLC with mkv movie 8.6Gb. VLC works around 2-3 minutes and eat all free memory and after system slow down. In 5-6 seconds system goes down more - mouse cursor not moving, switch to console extremely slow. Video on system hangs: https://youtu.be/73b8SxllTLs While system hangs it extremely much accessing to HDD. Please ask any logs/settings I'm ready to help. -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu. https://bugs.launchpad.net/bugs/159356 Title: System freeze on high memory usage Status in linux package in Ubuntu: Incomplete Bug description: I run a batch matlab job server here at my lab, running Dapper 6.06 (for the LTS). One of the users has submitted a very memory-consuming job, which successfully crashes the server. Upon closer inspection, the crash happens like this: 1. I run matlab with the given file (as an ordinary, unpriveleged user) 2. RAM usage quickly fills up 3. Once the RAM meter hits 100%, the system freezes: All SSH connections freeze up, and while switching VTs directly on the machine works, no new processes run - so one can't log in, or do anything if he is logged in. (Sometimes typing doesn't work at all) Note that the swap - while 7 gigs of it are available - is never used. (The machine has 7 gigs of RAM as well) I've tried the same on my Gutsy 32-bit box, and there was no system freezeup - matlab simply notified that the system was out of memory. However, it did this once memory was 100% in use - and still, swap didn't get used at all! (Though it is mounted correctly and shows up in "top" and "free"). So first thing's first - I'd like to eliminate the crash issue. I suppose I could switch the server to 32-bit, but I think that would be a performance loss, considering that it does a lot of heavy computation. There is no reason, however, that this should happen on a 64-bit machine anyway. Why does it? WORKAROUND: Enabling DMA in the BIOS To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/159356/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp
