Why not copy around data in physical RAM?
Posted Sep 9, 2004 14:56 UTC (Thu) by joern
In reply to: Why not copy around data in physical RAM?
Parent article: Kswapd and high-order allocations
The big problem with this approach are pointers. Most pointers contain the virtual address of some memory area, those don't matter. But some actually contain the physical or bus address. For example, ethernet hardware usually has DMA engines and writes to certain pages in main memory. If you tried to move those pages around, you'd have a lot of fun handling the random application coredumps and occasional kernel panic.
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