On Mon, Apr 28, 2014 at 02:58:41PM +0800, Shaohua Li wrote: > > The stripe cache has two goals: > 1. cache data, so next time if data can be found in stripe cache, disk access > can be avoided. I think this is mostly a side effect. We have a much larger and better tuned page cache to take care of this. > 2. stable data. data is copied from bio to stripe cache and calculated parity. > data written to disk is from stripe cache, so if upper layer changes bio data, > data written to disk isn't impacted. > > In my environment, I can guarantee 2 will not happen. Why just in your environment? Now that we got stable pages in the page cache this should always be the case. > Of course, this shouldn't be enabled by default, so I added an option to > control it. Unless careful benchmarking in various scenarious shows adverse effects this should be the default. And if we can find adverse effects we need to look into them. -- 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
