X is consuming ~100 GiB of RAM(!)
Vladimir Dergachev
volodya at mindspring.com
Wed Dec 6 12:23:21 UTC 2017
On Tue, 5 Dec 2017, Ewen Chan wrote:
> I'm a little bit confused by your reply here.
X is a network protocol, so it can be used to render to a remote display.
ssh -Y performs the forwarding over the tunnel.
However, in practice the forwarding only works for applications with
modest interface, like a gnome control panel or, better, xterm. firefox
pushes it already and any computer-aided design GL program is unlikely to
work well over it.
The main reason is not so much network bandwidth, but rather latency -
there are lots of calls that need a reply back and this slows down
rendering. Routing calls over ssh makes the issues worse.
On top of that network forwarding of GL calls does not use hardware
renderer - last time I checked, which was a while ago. So you should just
not ever do it. Use Xvnc if you must, but only for relatively simple GL
apps because Xvnc does software rendering.
For a non-GL app, you also have an option to Xvnc and this is better
because the app would still be there if the network connection is broken -
which could happen in out-of-memory condition.
The nice thing about trying Xvnc is that it is a separate Xserver and it
does not need Xorg running.
best
Vladimir Dergachev
> If it doesn't rely on GL, can you please help clarify why would I want to use Xvnc instead?
>
> (Was that suppose to be "If it DOES (rely on GL), to use Xvnc instead"?)
>
> Thanks.
>
> On Tue, Dec 5, 2017 at 7:17 PM, Vladimir Dergachev <volodya at mindspring.com> wrote:
>
>
> On Tue, 5 Dec 2017, Ewen Chan wrote:
>
> Not really sure.
> Someone suggested that I tried Xvfb but I didn't really know how I can use that without using an X server already, and again, in trying to conduct my own due
> diligence research into the
> issue, I stumbled upon using ssh -Y and enabling X11 forwarding via ssh so I will have to see how that works next (unless there are other suggestions that come
> before that that I can also
> quickly test out as well).
>
>
> If your app relies on GL you don't want to use ssh -Y.
>
> If it does not, then I recommend running it in Xvnc instead.
>
> best
>
> Vladimir Dergachev
>
>
> Thanks.
>
> On Tue, Dec 5, 2017 at 6:36 PM, Vladimir Dergachev <volodya at mindspring.com> wrote:
>
> Also, given the the high usage does not happen outside of gnome session, perhaps this is connected to compositing..
>
> best
>
> Vladimir Dergachev
>
> On Wed, 6 Dec 2017, Hi-Angel 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
>
> _______________________________________________
> xorg at lists.x.org: X.Org support
> Archives: http://lists.freedesktop.org/archives/xorg
> Info: https://lists.x.org/mailman/listinfo/xorg
> Your subscription address: %(user_address)s
>
> _______________________________________________
> xorg at lists.x.org: X.Org support
> Archives: http://lists.freedesktop.org/archives/xorg
> Info: https://lists.x.org/mailman/listinfo/xorg
> Your subscription address: %(user_address)s
>
>
>
>
>
>
More information about the xorg
mailing list