• Tag Archives memory
  • Fulong issues

    So, while I have been doing a compile of compiz on the Fulong, it wanted to compile kdebase as well. Fine, no big deal, except that it fails the compile of that package about halfway through. Upon restart of the compile it completes without any issues. This is a problem that I have seen (and reported) before with the Fulong, and now I think I have the answer as was so graciously bestowed upon me by Thiemo Seufer:

    The problem is a compound of
    1) Not enough RAM (only 512 MB) in some machines, which causes an
       increasing number of package builds to use swap, and some of them
       to evenutually fail to build because of a timeout.
    2) Slow on-board PIO IDE, from which the firmware can boot from
    3) A kernel-imposed limit of 1 GB when PCI DMA devices (like a SATA
       disk controller) is used.
    4) A kernel bug in the cache coherency management which hits PIO IDE,
       and causes instability since kernel 2.6.18. Up to then, the problem
       was mostly papered over by an excessive amount of cache flushing in
       the kernel code. This problem went unnoticed upstream since PIO IDE
       is these days only used on very small/cheap systems, where a
       different code path is used.

    So, the first one is the most telling, at least for my situation. I suppose the other problems (at least 2 and 4… 3 doesn’t apply since I don’t (and cannot)  have SATA controllers on the Fulong at this time) are also applicable, but I haven’t really noticed them one way or another.

    Thiemo notes that problem 3 has supposedly been fixed in kernel 2.6.22+, and since I am running 2.6.23.14 at the moment, this should be fixed for me as well, not that it matters. He also has a fix in for 4, and it is waiting for upstream review. 2? Well, his solution is to add SATA disks, so apparently it is not really a problem for me.

    His answer to 1 is to add memory to the system, and recommends 1-2gb. Well, seeing as I already have 1gb in the system, obviously this is still an issue regardless of what he recommends, and hopefully a real solution will come about.