Hi Here I'm sending patches that add funcionality provided by dm-latency into dm-statistics framework. Dm-latency was introduced in this post https://www.redhat.com/archives/dm-devel/2015-February/msg00158.html , however, there is already similar framework dm-statistics in the kernel. In order to have cleaner and easier to maintain code, it is better to integrate dm-latency functionality into dm-statistics, rather than having two frameworks that do similar things. This patch series makes these changes: * it is possible to use precise time measurement with nanosecond granularity (previously, time was measured in jiffies) * it is possible to collect histogram of latencies. The histogram boundaries may be selected by the user and there is unlimited number of possible boundaries (in dm-latency, the histogram boundaries were fixed) * it is possible to use dm-statistics on multipath The documentation of these extensions is in Documentation/device-mapper/statistics.txt I'd like to ask people who designed dm-latency to check this patchset, try to use it and tell us if it provides sufficient functionality to them (the indended functinality of dm-latency was to predict hard disk failures from i/o request latency histogram). Mikulas -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
