On Fri, Jan 16, 2009 at 4:51 AM, Yuri Tikhonov <yur@xxxxxxxxxxx> wrote: > The reason why I preferred to use async_pq() instead of async_xor() > here is to maximize the chance that the whole D+D recovery operation > will be handled in one ADMA device, i.e. without channels switch and > the latency introduced because of that. > This should be a function of the async_tx_find_channel implementation. The default version tries to keep a chain of operations on one channel. struct dma_chan * __async_tx_find_channel(struct dma_async_tx_descriptor *depend_tx, enum dma_transaction_type tx_type) { /* see if we can keep the chain on one channel */ if (depend_tx && dma_has_cap(tx_type, depend_tx->chan->device->cap_mask)) return depend_tx->chan; return dma_find_channel(tx_type); } -- Dan -- To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html