Steven Rostedt <[EMAIL PROTECTED]> wrote: > > I will also admit that my ring buffers lost one byte per page. Because > I wanted to save on space with the accounting, and only had a start and > end pointer per page. So when start and end were equal, the buffer was > considered empty and when end was one less than start, it was considered > full. But since end always pointed to an empty spot, it would still be > empty when the buffer was full, thus wasting one byte per page. But to > solve this, I would either have to add another variable in the buffer > page descriptor (adding at least one byte, but probably 4 bytes) which > would just be more waste, or I would have to make a complex system even > more complex (ie. adding a flag on the end pointer at the MSB to > differentiate between end being empty or filled).
Nope. Just make the indices 32-bit numbers and let them wrap. Full: (tail - head) == size Empty: (tail - head) == 0 Add item: buf[head++ & (size-1)] = item; Remove item: buf[tail++ & (size-1)] - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
