GNOME memory
Tuesday Feb 22, 2005
A question on the Java Desktop System Developer forum got me to thinking about memory usage of the GNOME desktop and various basic applications. Whenever I give a talk on JDS or GNOME, one of the most common complaints/questions is why does X use so much memory? (Where X is nautilus, metacity, mozilla, clock-applet...)
While answering the forum posting, I learned something. Here is the output of prstat -s size (sorted by resident memory size) on an ordinary Java Desktop System GNOME desktop:
-bash-3.00$ prstat -s size
PID USERNAME SIZE RSS STATE PRI NICE TIME CPU PROCESS/NLWP
434 root 58M 23M sleep 59 0 0:00:08 0.1% Xorg/1
637 root 50M 25M sleep 59 0 0:00:01 0.0% nautilus/4
658 root 45M 17M sleep 59 0 0:00:07 0.1% gnome-terminal/2
578 root 41M 16M sleep 59 0 0:00:00 0.0% gnome-session/1
635 root 39M 14M sleep 59 0 0:00:01 0.0% gnome-panel/1
593 root 36M 9512K sleep 59 0 0:00:00 0.0% gnome-settings-/1
650 root 36M 12M sleep 59 0 0:00:00 0.0% wnck-applet/1
652 root 36M 10M sleep 59 0 0:00:02 0.1% gnome-netstatus/1
648 root 35M 11M sleep 59 0 0:00:00 0.0% clock-applet/1
654 root 35M 9784K sleep 59 0 0:00:01 0.0% mixer_applet2/1
656 root 34M 9120K sleep 59 0 0:00:00 0.0% notification-ar/1
639 root 34M 8240K sleep 59 0 0:00:00 0.0% gnome-volcheck/1
640 root 34M 2164K sleep 59 0 0:00:00 0.0% gnome-volcheck/1
631 root 32M 9892K sleep 59 0 0:00:00 0.0% metacity/1
583 root 12M 10M sleep 59 0 0:00:01 0.0% gconfd-2/1
7 root 9944K 7628K sleep 59 0 0:00:02 0.0% svc.startd/12
9 root 8760K 7780K sleep 59 0 0:00:06 0.0% svc.configd/19
629 root 7868K 3616K sleep 59 0 0:00:00 0.0% gnome-smproxy/1
478 root 7692K 2984K sleep 59 0 0:00:00 0.0% dtlogin/1
1156 root 7468K 3708K sleep 59 0 0:00:00 0.0% sshd/1
1159 bnitz 7428K 2248K sleep 59 0 0:00:00 0.0% sshd/1
Total: 72 processes, 184 lwps, load averages: 0.01, 0.01, 0.02
35 Meg for a clock applet! Sigh. But wait a minute what is "SIZE" measuring?
man prstat shows:
SIZE
The total virtual memory size of the process, including all mapped files and devices, in kilobytes (K), mega- bytes (M), or gigabytes (G).
Here is an explanation from GNOME's Miguel de Icaza on how to interpret memory statistics In this case size isn't very useful. It just tells us how much address space the process maps, not how much memory the process consumes!
What about resident set size (RSS)? Well it's a somewhat more meaningful statistic, but it also includes memory used by shared libraries. But the whole idea of shared libraries is that they are shared, that is, several processes can use a library without having multiple copies of the library in memory. For a typical GNOME application/applet, everything from libc to libX11, libgtk... is counted multiple times! And as Miguel's article explains, RSS doesn't count memory which is swapped out. So on the one hand we are massively overestimating the memory usage for applications which use many shared libraries (e.g. GNOME applications) and on the other hand we are underestimating the memory usage for applications which may be swapped out.
The manpage for prstat (Solaris) mentions another memory utility called pmap, which can give more detailed memory statistics for a process. For our clock-applet process:
# pmap -x 648 648: /usr/lib/clock-applet --oaf-activate-iid=OAFIID:GNOME_ClockApplet_Fact Address Kbytes RSS Anon Locked Mode Mapped File 0803E000 40 40 40 - rwx-- [ stack ] 08048000 132 132 - - r-x-- clock-applet 08078000 16 16 12 - rwx-- clock-applet 0807C000 4 - - - rwx-- clock-applet 0807D000 1260 1248 1248 - rwx-- [ heap ] D0400000 11476 504 - - r-x-- libmlib_sse2.so.2 D0F44000 304 128 104 - rwx-- libmlib_sse2.so.2 D0F90000 4 - - - rwx-- libmlib_sse2.so.2 D112E000 384 128 - - rwxs- [ shmid=null ] D1190000 4 4 4 - rwx-- [ anon ] D11A0000 4 4 - - r-x-- pango-basic-fc.so D11B0000 8 8 8 - rwx-- pango-basic-fc.so D11C0000 4 4 - - r-x-- 646%UTF-8.so D11D0000 8 8 4 - rwx-- 646%UTF-8.so D11E0000 4 4 4 - rwx-- [ anon ] D11F0000 192 148 - - r-x-- libpng12.so.0.1.2.5 D122F000 8 8 8 - rwx-- libpng12.so.0.1.2.5 D1240000 12 12 - - r-x-- libpixbufloader-png.so D1252000 4 4 4 - rwx-- libpixbufloader-png.so D1260000 12 12 - - r-x-- libmp.so.2 D1273000 4 4 4 - rw--- libmp.so.2 D1280000 24 20 - - r-x-- libuutil.so.1 D1296000 4 4 4 - rw--- libuutil.so.1 D12A0000 4 4 - - r-x-- libdoor.so.1 D12B1000 4 4 4 - rw--- libdoor.so.1 D12C0000 88 88 - - r-x-- libscf.so.1 D12E6000 4 4 4 - rw--- libscf.so.1 D12F0000 44 44 - - r-x-- libblueprint.so D130A000 4 4 4 - rwx-- libblueprint.so D1310000 4 4 - - r-x-- UTF-8%646.so D1320000 4 4 4 - rwx-- UTF-8%646.so D132D000 68 60 - - r---- dev:102,0 ino:5950 D1340000 4 4 - - r-x-- UTF-8%8859-1.so D1350000 4 4 4 - rwx-- UTF-8%8859-1.so D1361000 4 4 - - rwxs- [ anon ] D1370000 12 12 12 - rwx-- [ anon ] D1380000 4 4 4 - rwx-- [ anon ] D1390000 4 4 - - r-x-- libmd5.so.1 D13A1000 4 4 4 - rw--- libmd5.so.1 D13B0000 28 12 - - r-x-- libaio.so.1 D13C7000 4 4 4 - rw--- libaio.so.1 D13C8000 4 - - - rw--- libaio.so.1 D13D0000 4 4 4 - rwx-- [ anon ] D13E0000 228 156 - - r-x-- libexpat.so.0.5.0 D1428000 8 8 8 - rwx-- libexpat.so.0.5.0 D1430000 4 4 4 - rwx-- [ anon ] D1440000 4 4 4 - rwx-- [ anon ] D1450000 72 52 - - r-x-- libXext.so.0 D1472000 4 4 4 - rw--- libXext.so.0 D1480000 28 24 - - r-x-- libXi.so.5 D1497000 4 4 4 - rw--- libXi.so.5 D14A0000 12 12 - - r-x-- libXrandr.so.2 D14B3000 4 4 4 - rw--- libXrandr.so.2 D14C0000 4 4 4 - rwx-- [ anon ] D14D0000 4 4 4 - rwx-- [ anon ] D14E0000 24 20 - - r-x-- librt.so.1 D14F6000 4 4 4 - rw--- librt.so.1 D1500000 24 20 20 - rwx-- [ anon ] D1510000 916 428 - - r-x-- libcrypto.so.0.9.7 D1605000 84 72 72 - rw--- libcrypto.so.0.9.7 D161A000 8 4 4 - rw--- libcrypto.so.0.9.7 D1620000 4 4 4 - rwx-- [ anon ] D1630000 200 64 - - r-x-- libssl.so.0.9.7 D1672000 12 12 12 - rw--- libssl.so.0.9.7 D1680000 40 40 - - r-x-- libORBitCosNaming-2.so.0.0.0 D1699000 8 8 8 - rwx-- libORBitCosNaming-2.so.0.0.0 D16A0000 4 4 4 - rwx-- [ anon ] D16B0000 108 20 - - r-x-- libaudiofile.so.0.0.2 D16DA000 12 12 12 - rwx-- libaudiofile.so.0.0.2 D16E0000 28 8 - - r-x-- libesd.so.0.2.32 D16F6000 8 8 8 - rwx-- libesd.so.0.2.32 D1700000 4 4 4 - rwx-- [ anon ] D1710000 420 248 - - r-x-- libfreetype.so.6 D1788000 36 36 36 - rwx-- libfreetype.so.6 D17A0000 200 180 - - r-x-- libfontconfig.so.1 D17E1000 20 20 20 - rwx-- libfontconfig.so.1 D17E6000 4 4 4 - rwx-- libfontconfig.so.1 D17F0000 24 24 - - r-x-- libXrender.so.1 D1806000 4 4 4 - rw--- libXrender.so.1 D1810000 60 56 - - r-x-- libXft.so.2 D182F000 4 4 4 - rw--- libXft.so.2 D1840000 4 4 4 - rwx-- [ anon ] D1850000 488 392 - - r-x-- libX11.so.4 D18DA000 16 16 16 - rw--- libX11.so.4 D18E0000 4 4 4 - rwx-- [ anon ] D18F0000 104 72 - - r-x-- libjpeg.so.62.0.0 D1919000 4 4 4 - rwx-- libjpeg.so.62.0.0 D1920000 24 8 - - r-x-- libgailutil.so.17.0.1 D1935000 4 4 4 - rwx-- libgailutil.so.17.0.1 D1940000 4 4 4 - rwx-- [ anon ] D1950000 28 12 - - r-x-- libgnome-keyring.so.0.0.0 D1966000 4 4 4 - rwx-- libgnome-keyring.so.0.0.0 D1970000 4 4 4 - rwx-- [ anon ] D1980000 728 640 - - r-x-- libc.so.1 D1A46000 24 24 24 - rw--- libc.so.1 D1A4C000 8 8 8 - rw--- libc.so.1 D1A50000 16 16 - - r-x-- libthread.so.1 D1A60000 4 4 4 - rwx-- [ anon ] D1A70000 512 400 - - r-x-- libglib-2.0.so.0.400.1 D1AFF000 4 4 4 - rwx-- libglib-2.0.so.0.400.1 D1B10000 8 8 - - r-x-- libgmodule-2.0.so.0.400.1 D1B21000 4 4 4 - rwx-- libgmodule-2.0.so.0.400.1 D1B30000 220 220 - - r-x-- libgobject-2.0.so.0.400.1 D1B76000 4 4 4 - rwx-- libgobject-2.0.so.0.400.1 D1B80000 172 156 - - r-x-- libpango-1.0.so.0.400.1 D1BBA000 20 20 20 - rwx-- libpango-1.0.so.0.400.1 D1BD0000 4 4 4 - rwx-- [ anon ] D1BE0000 36 12 - - r-x-- libpangox-1.0.so.0.400.1 D1BF8000 8 8 8 - rwx-- libpangox-1.0.so.0.400.1 D1C00000 8720 236 - - r-x-- libmlib.so.2 D2493000 68 32 24 - rwx-- libmlib.so.2 D24B0000 12 12 - - r-x-- libpangoxft-1.0.so.0.400.1 D24C2000 8 8 8 - rwx-- libpangoxft-1.0.so.0.400.1 D24D0000 268 60 - - r-x-- libm.so.2 D2522000 16 8 8 - rwx-- libm.so.2 D2530000 4 4 4 - rwx-- [ anon ] D2540000 80 72 - - r-x-- libgdk_pixbuf-2.0.so.0.400.9 D2563000 8 8 8 - rwx-- libgdk_pixbuf-2.0.so.0.400.9 D2570000 80 72 - - r-x-- libatk-1.0.so.0.700.3 D2593000 8 8 8 - rwx-- libatk-1.0.so.0.700.3 D25A0000 372 356 - - r-x-- libgdk-x11-2.0.so.0.400.9 D260C000 20 20 16 - rwx-- libgdk-x11-2.0.so.0.400.9 D2620000 512 396 - - r-x-- libnsl.so.1 D26A0000 20 20 20 - rw--- libnsl.so.1 D26A5000 32 24 24 - rw--- libnsl.so.1 D26B0000 4 4 4 - rwx-- [ anon ] D26C0000 44 36 - - r-x-- libsocket.so.1 D26DB000 4 4 4 - rw--- libsocket.so.1 D26E0000 40 32 - - r-x-- libz.so.1 D26F9000 8 8 8 - rwx-- libz.so.1 D2700000 12 12 - - r-x-- libpthread.so.1 D2710000 864 372 - - r-x-- libxml2.so.2 D27F7000 40 40 40 - rwx-- libxml2.so.2 D2801000 32 4 4 - rwx-- libxml2.so.2 D2810000 4 4 4 - rwx-- [ anon ] D2820000 2416 1444 - - r-x-- libgtk-x11-2.0.so.0.400.9 D2A8B000 40 40 40 - rwx-- libgtk-x11-2.0.so.0.400.9 D2A95000 4 4 4 - rwx-- libgtk-x11-2.0.so.0.400.9 D2AA0000 76 24 - - r-x-- libglade-2.0.so.0.0.3 D2AC2000 8 8 8 - rwx-- libglade-2.0.so.0.0.3 D2AD0000 12 8 - - r-x-- libgthread-2.0.so.0.400.1 D2AE2000 4 4 4 - rwx-- libgthread-2.0.so.0.400.1 D2AF0000 216 168 - - r-x-- libresolv.so.2 D2B36000 8 8 8 - rw--- libresolv.so.2 D2B40000 4 4 4 - rwx-- [ anon ] D2B50000 252 240 - - r-x-- libORBit-2.so.0.0.0 D2B9E000 32 32 32 - rwx-- libORBit-2.so.0.0.0 D2BB0000 68 68 - - r-x-- libbonobo-activation.so.4.0.0 D2BD0000 8 8 8 - rwx-- libbonobo-activation.so.4.0.0 D2BE0000 304 284 - - r-x-- libgnomevfs-2.so.0.600.0 D2C3B000 20 20 20 - rwx-- libgnomevfs-2.so.0.600.0 D2C40000 4 4 4 - rwx-- libgnomevfs-2.so.0.600.0 D2C50000 4 4 4 - rwx-- [ anon ] D2C60000 184 184 - - r-x-- libgconf-2.so.4.1.0 D2C9D000 12 12 12 - rwx-- libgconf-2.so.4.1.0 D2CB0000 292 280 - - r-x-- libbonobo-2.so.0.0.0 D2D08000 40 40 40 - rwx-- libbonobo-2.so.0.0.0 D2D20000 132 36 - - r-x-- libpangoft2-1.0.so.0.400.1 D2D50000 4 4 4 - rwx-- libpangoft2-1.0.so.0.400.1 D2D60000 80 12 - - r-x-- libart_lgpl_2.so.2.3.16 D2D83000 4 4 4 - rwx-- libart_lgpl_2.so.2.3.16 D2D90000 4 4 4 - rwx-- [ anon ] D2DA0000 24 20 - - r-x-- libpopt.so.0.0.0 D2DB5000 4 4 4 - rwx-- libpopt.so.0.0.0 D2DC0000 72 72 - - r-x-- libgnome-2.so.0.600.0 D2DE1000 4 4 4 - rwx-- libgnome-2.so.0.600.0 D2DF0000 156 28 - - r-x-- libgnomecanvas-2.so.0.600.0 D2E26000 8 8 8 - rwx-- libgnomecanvas-2.so.0.600.0 D2E30000 328 300 - - r-x-- libbonoboui-2.so.0.0.0 D2E91000 12 12 12 - rwx-- libbonoboui-2.so.0.0.0 D2EA0000 4 4 4 - rwx-- [ anon ] D2EB0000 64 64 - - r-x-- libICE.so.6 D2EC0000 4 4 4 - rw--- libICE.so.6 D2EC1000 8 - - - rw--- libICE.so.6 D2ED0000 28 28 - - r-x-- libSM.so.6 D2EE7000 4 4 4 - rw--- libSM.so.6 D2EF0000 524 328 - - r-x-- libgnomeui-2.so.0.600.1 D2F82000 16 16 16 - rwx-- libgnomeui-2.so.0.600.1 D2F90000 4 4 4 - rwx-- [ anon ] D2FA0000 56 52 - - r-x-- libpanel-applet-2.so.0.0.19 D2FBD000 8 8 8 - rwx-- libpanel-applet-2.so.0.0.19 D2FD0000 4 4 - - r-x-- libdl.so.1 D2FDB000 128 128 - - r-x-- ld.so.1 D2FFB000 4 4 4 - rwx-- ld.so.1 D2FFC000 8 8 8 - rwx-- ld.so.1 -------- ------- ------- ------- ------- total Kb 36292 12264 2336 -
What does this mean?
Again from the pmap man page. Resident memory is 12264 Kilobytes but much of this physical memory can be shared with other instances of the clock applet. But the anon column, the memory used by each instance of a clock applet, that's kind of high too. Should a clock applet really take over 2 megabytes?Thanks Yusuf for pointing me to Ben Maurer's blog and a Wiki on GNOME memory usage. I think we're all pulling in the same direction here and as I learn more about which tools can be applied to this problem, I'll try to contribute what I learn.
There is certainly room for improvement on GNOME memory usage, but before we get started we need to make sure we are using meaningful measurements.
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This isn't the best time of year for sailing in Ireland but the weather cooperated on Saturday. We sailed my friend's boat to Dun Laoghaire to have it assessed for a possible trade up. This was the least amount of wind I'd sailed in in Dublin, about 15-20 knots out of the west veering west-southwest. Eyghtheen-24's aren't the fastest sailboat design on the planet, but we averaged a respectable 5.7 Miles/hour. It took us about 2 hours and 13 minutes to travel the 12.7 miles across Dublin bay.
