Hello, Here is a second revision of the patch series to fix estimate of writeback throughput when device is not fully busy doing writeback. Michael Stapelberg has reported that such workload (e.g. generated by linking) tends to push estimated throughput down to 0 and as a result writeback on the device is practically stalled. The first three patches fix the reported issue, the remaining two patches are unrelated cleanups of problems I've noticed when reading the code. Andrew, can you please pick up the series? Thanks! Honza Changes since v1: * Added comments to better explain the logic * Added Tested-by tag Previous versions: Link: http://lore.kernel.org/r/20210705161610.19406-1-jack@xxxxxxx # v1