On Mon, Sep 07, 2015 at 07:20:40AM +0200, Christoph Hellwig 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. Hi Christoph, Thanks for these work. Yes, I/O error handling is in the plan. We could simplify panic (people here like this option) or report error and bypass log. Any way an option is good. For the patches, FUA write does simplify things a lot. However, I tried it before, the performance is quite bad in SSD. FUA is off in SATA by default, the emulation is farily slow because FLUSH request isn't NCQ command. I tried to enable FUA in SATA too, FUA write is still slow in the SSD I tested. Other than this one, other patches look good: Reviewed-by: Shaohua Li <shli@xxxxxx> -- 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
