X is consuming ~100 GiB of RAM(!)

Wed Dec 6 12:25:16 UTC 2017

Keep in mind that Xorg will show memory usage from mapping graphics 
memory.. which could be large on your card.

Also, are you using CUDA ?

best

Vladimir Dergachev

On Wed, 6 Dec 2017, Hi-Angel wrote:

> Oh, wow, this looks like a Xorg bug then. I'd recommend trying latest Xorg then — yours one is 3 years old, hopefully it's something fixed. If it won't help, I'd recommend report a bug.
> Although ulimit workaround worth a try, but If this is really a memory leak, I doubt it'd help much. What I think would happen is that Xorg won't be able to allocate resources on apps'
> behalf, making apps to crash.
> 
> On 6 December 2017 at 00:49, Ewen Chan <chan.ewen at gmail.com> wrote:
>       Thank you, Hi-Angel.
> I thought so too originally, but when I am launching the analysis via a terminal on the console (or even via ssh from cygwin into the system) and it is still exhibiting the same
> behaviour despite the fact that there isn't any graphical component running beyond just runlevel 5 (and having GNOME running on X), issuing the ps aux command shows Xorg being the
> culprit for the high memory consumption.
> 
> In trying to perform the forensic analysis, I would think that it would be true if there is a graphic component that's actually running, but there isn't (beyond runlevel
> 5/GNOME-on-X).
> 
> X is supposed to release the memory back into the available pool, but it doesn't -- it just keeps increasing.
> 
> So even after the application has terminated, if X doesn't release the memory back, then ps aux will show X as being the process that's holding the memory.
> 
> Again, the idea of providing the first link was to limit how much RAM can X use for the caching/retention (using ulimit -m somehow and editing /etc/security/limits.conf) and I raised
> the question (on the SLES forum) how would I know what I should set the limit at? Too low and it will crash often. Too high, and I am back to this current problem that I am
> experiencing now.
> 
> 
> [IMAGE]
> 
> 
> (sorry that the output of xrestop above is a screenshot because I am twice remotely logged in (first to home system and then again via the IPMI to the console).)
> 
> xrestop only shows about 22 MiB.
> 
> ps aux | grep Xorg is still showing about 100 GiB tied to the Xorg process.
> 
> Thanks.
> 
> Sincerely,
> Ewen
> 
> 
> On Tue, Dec 5, 2017 at 4:28 PM, Hi-Angel <hiangel999 at gmail.com> wrote:
>       The troubleshooting link you provided states that the high memory
>       usage typically belongs to some other application. Sorry, I am just an
>       occasional bystander here, and can't tell much of technical details,
>       but I imagine it works like this(I hope someone will correct me on
>       details): an app requests, for example, a glx object, and XServer
>       allocates one. When the app is done with the object, it requests
>       XServer to deallocate it. The point is: although this memory accounted
>       on part of XServer process — it is actually owned by the app. The link
>       also states that you can use `xrestop` application to see the owners
>       and amounts of the memory.
>
>       On 5 December 2017 at 21:14, Ewen Chan <chan.ewen at gmail.com> wrote:
>       > To Whom It May Concern:
>       >
>       > Hello everybody. My name is Ewen and I am new to this distribution list.
>       >
>       > So let me start with a little bit of background and the problem statement of
>       > what I am seeing/encountering.
>       >
>       > I am running a SuperMicro Server 6027TR-HTRF
>       > (https://www.supermicro.com/products/system/2u/6027/sys-6027tr-htrf.cfm)
>       > (which uses a Matrox G200eW graphics chip and it has four half-width nodes,
>       > each node has two processor, each processor is an Intel Xeon E5-2690 (v1)
>       > (8-core, 2.9 GHz stock, HTT disabled) running SuSE Linux Enterprise Server
>       > 12 SP1 (SLES 12 SP1).
>       >
>       > Here are some of the outputs from the system:
>       >
>       > ewen at aes4:~> X -version
>       >
>       > X.Org X Server 1.15.2
>       > Release Date: 2014-06-27
>       > X Protocol Version 11, Revision 0
>       > Build Operating System: openSUSE SUSE LINUX
>       > Current Operating System: Linux aes4 3.12.49-11-default #1 SMP Wed Nov 11
>       > 20:52:43 UTC 2015 (8d714a0) x86_64
>       > Kernel command line: BOOT_IMAGE=/boot/vmlinuz-3.12.49-11-default
>       > root=UUID=fc4dcdb9-2468-422c-b29f-8da42fd7dec0
>       > resume=/dev/disk/by-uuid/1d5d8a9c-218e-4b66-b094-f5154ab08434 splash=silent
>       > quit showopts crashkernel=123M,high crashkernel=72M,low
>       > Build Date: 12 November 2015  01:23:55AM
>       >
>       > Current version of pixman: 0.32.6
>       >          Before reporting problems, check http://wiki.x.org
>       >          to make sure that you have the latest version.
>       > ewen at aes4:~> uname -a
>       > Linux aes4 3.12.49-11-default #1 SMP Wed Nov 11 20:52:43 UTC 2015 (8d714a0)
>       > x86_64 x86_64 x86_64 GNU/Linux
>       >
>       > The problem that I am having is that I am running a CAE analysis application
>       > and during the course of the run, X will eventually consume close to 100 GiB
>       > of RAM (out of 125 GiB installed)
>       >
>       > ewen at aes4:~> date
>       > Tue Dec 5 05:08:28 EST 2017
>       > ewen at aes4:~> ps aux | grep Xorg
>       > root 2245 7.7 79.0 271100160 104332316 tty7 Ssl+ Nov25 1078:19 /usr/bin/Xorg
>       > :0 -background none -verbose -auth /run/gdm/aut
>       > h-for-gdm-9L7Ckz/database -seat seat0 -nolisten tcp vt7
>       > ewen 11769 0.0 0.0 10500 944 pts/1 R+ 05:08 0:00 grep --color=auto Xorg
>       >
>       > This does not occur when I perform the same analysis in runlevel 3 and when
>       > I switch back to runlevel 5 and I am using GNOME for the desktop
>       > environment, regardless of whether I initiate the analysis via a Terminal
>       > inside GNOME or I ssh into the system (via cygwin from a Windows box), the
>       > host server's X memory usage will continually increase as the analysis
>       > progresses.
>       >
>       > In trying to research this issue, I have found that I can either restrict
>       > the amount of cache that X does via ulimit -m (Source:
>       > https://wiki.ubuntu.com/X/Troubleshooting/HighMemory) or I can edit
>       > xorg.conf by adding this option:
>       >
>       > Option "XaaNoPixmapCache"
>       >
>       > (Source: https://www.x.org/releases/current/doc/man/man5/xorg.conf.5.xhtml)
>       >
>       > Would that be the recommended solution to the problem that I am experiencing
>       > with X?
>       >
>       > A couple of other notes:
>       >
>       > ewen at aes4:~> free -g
>       >              total       used       free     shared    buffers     cached
>       > Mem:           125        125          0          0          0          3
>       > -/+ buffers/cache:        122          3
>       > Swap:          256        170         85
>       > ewen at aes4:~> cat /proc/sys/vm/vfs_cache_pressure
>       > 200
>       >
>       > Your help and commentary would be greatly appreciated. Thank you.
>       >
>       > Sincerely,
>       >
>       > Ewen Chan
>       >
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