On 9/11/15, 11:17 PM, "Christoph Hellwig" <hch@xxxxxx> wrote: >Hi Shaohua, hi Neil, > >this series contains a few updates to the raid5-cache feature. > >The first patch just ports it to the post-4.2 block layer. As part of >that >I noticed that it currently doesn't handle I/O errors - fixes for that >will >follow. > >The second and third patch simplify the I/O unit state machine and reduce >latency and memory usage for the I/O units. The remainder are just a >couple >of cleanups in this area that I stumbled upon. > >Changes since V1: > - only use REQ_FUA if supported natively by the log device Hi Christoph, I finally got some data with a Samsung SSD, which supports fua. Controller is ahci. Test is a simple fio with all full stripe write. libata.fua=0, throughput 247m/s libata.fua=1, throughput 74m/s fua is significantly slower. I think we need a sysfs config to enable fua. Thanks, Shaohua -- 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
