![]() | |||||||||||||
Messages in this thread |
> Because much of the memory cannot be used for kernel objects there is an > imbalance in available resources and its very hard to balance them sanely. As I understand it, in a Linux / i686 system, there are three zones: DMA (0 - 2^24-1), low (2^24 - 2^30-1) and high (2^30 and up). And the hardware (PAE) apparently distinguishes memory addresses above 2^32-1 as well. Questions: 1. Shouldn't there be *four* zones: (DMA, low, high and PAE)? 2. Isn't the boundary at 2^30 really irrelevant and the three "correct" zones are (0 - 2^24-1), (2^24 - 2^32-1) and (2^32 - 2^36-1)? 3. On a system without ISA DMA devices, can DMA and low be merged into a single zone? 4. It's pretty obvious exactly which functions require memory under 2^24 -- ISA DMA. But exactly which functions require memory under 2^30 and which functions require memory under 2^32? It seems relatively easy to write a Perl script to truck through the kernel source and figure this out; has anyone done it? It would seem to me a valuable piece of information -- what the demands are for the relatively precious areas of memory under 1 GB and under 4 GB. -- M. Edward Borasky znmeb@borasky-research.net http://www.borasky-research.net - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/ | ||||||||||||
| Last update: 2005-03-22 12:15 [from the cache] ©2003-2008 | |||||||||||||