Whenever it's possible to avoid a copy, b_xfer() will simply swap the buffer's heads without touching the data. This has brought the performance back from 140 kH/s to 202 kH/s on the test case.
Whenever it's possible to avoid a copy, b_xfer() will simply swap the buffer's heads without touching the data. This has brought the performance back from 140 kH/s to 202 kH/s on the test case.