My wife and I share a home office with two Linux computers. One of them is fast, and one slow. I have recently reorganized that office so I am using the slow computer in X-terminal mode. Instead of running something complicated like ltsp to turn that computer into an X-terminal, I instead run "X -query fasthostname" to connect to the XDM (X display manager) on the fast computer which allows me to log into that fast computer and do all my work there transparently and with the same speed (except for -dev xcairo, see below) as if I were actually sitting at the keyboard attached to the fast host. The only software required to be installed on the slow computer is the Linux kernel, a minimal Debian core install + an X server and (SiS) X driver. One reason why I have used X terminals for years is it is a tremendous way to utilize old computers that would be slow if they ran desktop applications on their own. (For years I used a pentium-133 as my slow computer X-terminal with no feeling that I wasn't sitting at the keyboard of the faster computer). Also, there is a huge advantage that the slow computer does not have any KDE or any other development or desktop software packages installed so system maintenance is greatly simplified on that computer.
Since moving from the fast computer to this X-terminal system I have noticed no difference in speed except for the -dev xcairo case for example 17. For that case, xcairo generates a ton of LAN traffic (which I track with the KDE4 system monitor) which essentially freezes my whole X-terminal so it is difficult to even change from one window to another. I then tried the same example on the fast computer, and for that case -dev xcairo was abnormally slow (I have remarked on that before) compared to the rest of the interactive devices such as -dev xwin, -dev qtwidget, -dev wxwidgets, etc. All those other devices eventually transform plplot commands to reasonably efficient Xorg commands. However, for -dev xcairo, the transformation is to grossly inefficient Xorg commands so that Xorg grabs all the CPU time when X clients are run locally and grabs all the LAN bandwidth for the X-terminal case where X clients are run remotely. This is not an overall issue with every cairo device since pscairo has normal speed for example 17. So the issue must be something special about the way xcairo implements the special interactive needs of example 17 that is done extremely inefficiently compared to all other interactive devices and also inefficiently compared to -dev pscairo. This issue is especially annoying right now because it completely wipes out my ability to run the test_interactive target from my X-terminal (I think it would take something like a half hour of an almost completely frozen desktop to finish example 17 in this mode) and it certainly must be boring for users running local X clients to have interactive use of -dev xcairo substantially slower than all other interactive devices. To work around the issue, I have just (revision 10780) removed example 17 from the tests that are done for the test_interactive target. However, I would like to restore example 17 to that suite of tests so could someone with knowledge of the cairo device driver please fix this xcairo interactive extreme inefficiency issue? Alan __________________________ Alan W. Irwin Astronomical research affiliation with Department of Physics and Astronomy, University of Victoria (astrowww.phys.uvic.ca). Programming affiliations with the FreeEOS equation-of-state implementation for stellar interiors (freeeos.sf.net); PLplot scientific plotting software package (plplot.org); the libLASi project (unifont.org/lasi); the Loads of Linux Links project (loll.sf.net); and the Linux Brochure Project (lbproject.sf.net). __________________________ Linux-powered Science __________________________ ------------------------------------------------------------------------------ The Planet: dedicated and managed hosting, cloud storage, colocation Stay online with enterprise data centers and the best network in the business Choose flexible plans and management services without long-term contracts Personal 24x7 support from experience hosting pros just a phone call away. http://p.sf.net/sfu/theplanet-com _______________________________________________ Plplot-devel mailing list Plplot-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/plplot-devel
