I noticed improvements involving this bug starting with 4.17. In 4.17, freezes over 2 min are uncommon. Even with over 2 gigs of swap used.
-- 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: When DMA is disabled 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
