Ok, so I have investigated some more and found several interesting links. A very similar Debian bugreport, which seemed to right itself misteriously:
http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=326956 In Ubuntu forums: http://ubuntuforums.org/showthread.php?t=440038&page=6 Interestingly, the last post (as of now, by Tsu Dho Nimh 1 week ago) mentions that using very large images seems to trigger the error, which is consistent with what I am seeing. I would guess that something is preventing old images from being freed, and/or having their space effectively used/returned to the stack. Interestingly, as per one of the Gentoo user's post, I used pmap on the Xorg process. Here are the first lines of a typical pmap: 8<---8<---8<---8<---8<---8<--- 6148: /usr/bin/X :0 -br -audit 0 -auth /var/lib/gdm/:0.Xauth -nolisten tcp vt7 Address Kbytes RSS Anon Locked Mode Mapping 0000000000400000 1764 - - - r-x-- Xorg 00000000007b9000 68 - - - rw--- Xorg 00000000007ca000 310936 - - - rw--- [ anon ] 0000000041543000 8 - - - rwx-- zero 00007f2360c2e000 96 - - - rw-s- [ shmid=0x13a807f ] 00007f2360c46000 7592 - - - r---- kochi-gothic-subst.ttf 00007f23613b0000 284 - - - rw-s- [ shmid=0x13a007e ] 8<---8<---8<---8<---8<---8<--- By looking at base addresses, there is a different between the first four values and the rest of the file, so they probably are some kind of special buffer. Specifically, the [ anon ] block at 0x7ca000 is highly suspicious, since it does not have execute permissions, and (more importantly) is huge, at over 300 Mb. If I change the background now, hey presto, the [ anon ] block grows by about 20 Mb, which is roughly the same amount that the Xorg memory usage does (according to htop and to pmap). This is repeatable, so that seems to be the problem. Now, if somebody knows what that [ anon ] block is used for... I think the rest of the pmap is fairly uninteresting; there are some changes, but the ballooning of the used memory is due to the first [ anon ] block (if there is any other contribution, it is negligible). I can attach them if you are interested, though. -- xorg memory leak when changing desktop wallpapers (Gnome) https://bugs.launchpad.net/bugs/254107 You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs