> Doesn't linux do shared-read-only mapping of pages on read(2) and only copy if you modify? Though it can only do so on page-aligned buffers. Maybe results wou

> Doesn't linux do shared-read-only mapping of pages on read(2) and only copy if you modify? Though it can only do so on page-aligned buffers. Maybe results would be different if the buffers were aligned? Page table modifications slow down your program and many read(2) calls are short and frequent. I doubt that would be a helpful optimization unless the buffer sizes are big.