Hello, Here is the fourth 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 v3: * Now really send updated patches and not previous version :-| Changes since v2: * Rebased on top of 5.14-rc1 * Fixed compilation failure introduced by patch 5/5 Changes since v1: * Added comments to better explain the logic * Added Tested-by tag * Added WRITE_ONCE calls matching READ_ONCE in patch 5/5 Previous versions: Link: http://lore.kernel.org/r/20210705161610.19406-1-jack@xxxxxxx # v1 Link: http://lore.kernel.org/r/20210712165811.13163-1-jack@xxxxxxx # v2 Link: http://lore.kernel.org/r/20210713103347.8364-1-jack@xxxxxxx # v3