On Tue, Nov 07, 2006 at 08:28:00PM +0100, Daniel Hartmeier wrote: > On Tue, Nov 07, 2006 at 06:08:52PM +0000, Paul Pruett wrote: > > > A nominal i386 computer with only a meg of ram > > without limit changes would not load it. > > Neither would a stock GENERIC kernel on any architecture. The reason is > that those 600+MB of table entries are allocated from kernel memory. And > the kernel only gets a fraction of the physical RAM installed. You'll > have to try, but I doubt you'll end up with more than half a gig of > kernel memory even if you put in 4+GB of RAM. > > And, no, I don't know if it's possible to tune that or how ;) > > The opposite is obviously true, i.e. if you have less than 600MB of > physical RAM, there is no way you can load 600+MB of table entries. >
Actually adding more RAM to a box may reduce the ammount of memory usable to pf. This comes from the fact that the kernel has a fixed virtual memory size but adding more RAM increases the "static" allocations (page table, buffer cache, etc.). So in the end you have suddenly less memory left. .. and no I don't know where the break even is. -- :wq Claudio
