This patch set is an effort to make bcache writes back dirty data when it is idle. Junhui Tang posted a fix days before, which IMHO has unstable interfere to writeback rate PD controller. This is another approach for same problem. The first patch with subject "bcache: do not perform writeback if dirty data is no more than writeback_percent" makes writeback_percent works as designed. This patch is depended by the seconded patch. The second patch with subject "bcache: implement max_writeback_rate_when_idle option for writeback mode" implements an option to set a maximum writeback rate when bcache device is idle. Then dirty data can be wrote back to cached device and cleaned on cache device. After cache set is cleaned, the following write requests on bcache device won't trigger writeback unless dirty data exceeds writeback_percent. Please review the patch set, any comment is welcome :-) Thanks in advance. Coly Li -- To unsubscribe from this list: send the line "unsubscribe linux-bcache" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html