On Saturday 17 March 2007 19:17, Dan Williams wrote:
Yes, defaulting to 'y' is not necessary, but ASYNC_TX_DMA=y &&
DMA_ENGINE=n is an explicit feature of the interface. When DMA_ENGINE
is not selected all the asynchronous paths in the API are compiled
out. This allows subsytems, like md-raid5, to be written in an
asynchronous fashion without regard for the architecture[1] or
availability of offload engines.
The current implementation builds on my embedded PPC4xx system without any
disks the objects async_tx.o and xor.o into the kernel which I definitely
don't need and want. And I get something like:
async_tx: api initialized (sync-only)
xor: measuring software checksumming speed
8regs : 145.000 MB/sec
8regs_prefetch: 115.000 MB/sec
32regs : 176.000 MB/sec
32regs_prefetch: 135.000 MB/sec
xor: using function: 32regs (176.000 MB/sec)
upon bootup.
Best regards,
Stefan