On Tue, Feb 19, 2008 at 08:09:45PM -0800, David VomLehn wrote: > As we continue to investigate using high memory on MIPS, we keep coming up > with odd results. The basic mapping of high memory seems to be working > correctly, and if we use an INITRAMFS root filesystem, things seem to work. > Things also seem to work with an NFS root filesystem if we disable > preemption, though we get someone squirrelly behavior in some minor ways. > Has anyone else successfully been able to use high memory on a 32-bit MIPS > Linux port? I've written MIPS highmem support in late 2002 for a customer who back then wasn't interested in being the first through the 64-bit minefield. Which back then certainly was justified - but there are now fairly stable 64-bit Linux kernels available so if you happen to be running on 64-bit hardware don't even spend a nanosecond on thinking about 32-bit highmem kernels. Highmem fundamentally sucks rocks through a straw. Coming back to your question. Highmem was only ever tested to work on SB1 and somewhat later PMC-Sierra RM9000 cores, both being 64-bit. With the increasing maturity of 64-bit Linux interest in these went away and as the result the highmem code started a slow bitrot - unnoticed for many moons. Ralf
