Am Sat, 08 Apr 2017 21:33:20 +0200 schrieb Helmut Jarausch <jarau...@skynet.be>:
> Hi, > > since a few days my system eats up memory, uses SWAP space and gets > slow. > It might depend on xorg-server, but I don't know why. > > On a nearly idle system (except xorg-server and some XTerms) I have > MEM | tot 7.5G | free 2.9G | cache 1.2G | buff 114.6M > | slab 498.0M | shmem 848.3M | vmbal 0.0M | hptot 0.0M > > (My system has 8G memory installed) > > Adding up all terms except 'tot' I get 5.6G where are the remaining > 2G? And why is shmem 0.85G - I have even seen a value of 4G for > shmem although all tempfs filesystems > were nearly empty. > > When I stop the X-server I get > > MEM | tot 7.5G | free 6.9G | cache 387.4M | buff 118.4M > | slab 72.0M | shmem 1.4M | vmbal 0.0M | hptot 0.0M | > > > I haven't seen this in the last 10 years! > > I'm running kernel 4.11.0-rc5 but I doubt it has to do with the > kernel since the values without a running xorg-server are for the > same kernel. > > Has anybody seen something similar? It would be interesting to see the memory usage of the running processes. Start top and press Shift+M (and maybe press "c" also to see the complete command line) and watch the memory usage. When you start experiencing slowdowns, have a look at top again. For me, it was a runaway upower process some months ago. I'm using systemd, so I fixed it easily with the following drop-in: $ cat /etc/systemd/system/upower.service.d/99memory.conf [Service] MemoryLimit=512M Upower now is limited to 512M of RAM (tho, it can still occupy swap instead). That means, due to the resource limit RAM no longer filled up but swap did. But that was meaningless performance-wise (I have 16G RAM and 64G swap). Maybe you can also "fix" it in a similar way by jailing misbehaving processes into a limited amount of RAM with cgroups. Swap will still be used but not for running/interactive processes so it won't become slow. Strange enough: The moment I did this, the process stopped misbehaving. Cgroups also support controlling swap usage but it comes at the cost of additional memory usage (and probably also performance overhead), so I only activated the RAM controller. And I started to add some safety limits to other services, too. They now also dump their never-needed-again junk straight into swap if any memory allocation bugs would hit me. -- Regards, Kai Replies to list-only preferred.
