On 06/12/14 15:48, Christoph Hellwig wrote: > Bart and Robert have helped with some very detailed measurements that they > might be able to send in reply to this, although these usually involve > significantly reworked low level drivers to avoid other bottle necks.
In case someone would like to see the results of the measurements I ran, these results can be found here: https://docs.google.com/file/d/0B1YQOreL3_FxUXFMSjhmNDBNNTg. Two important conclusions from the data in that PDF document are as follows: - A small but significant performance improvement for the traditional SCSI mid-layer (use_blk_mq=N). - A very significant performance improvement for multithreaded workloads with use_blk_mq=Y. As an example, the number of I/O operations per second reported for the random write test increased with 170%. That means 2.7 times the performance of use_blk_mq=N. I think this means the scsi-mq patches are ready for wider use. Bart. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
