When bfq was merged into mainline, there were two I/O schedulers that implemented the proportional-share policy: bfq for blk-mq and cfq for legacy blk. bfq's interface files in the blkio/io controller have the same names as cfq. But the cgroups interface doesn't allow two entities to use the same name for their files, so for bfq we had to prepend the "bfq" prefix to each of its files. However no legacy code uses these modified file names. This naming also causes confusion, as, e.g., in [1]. So we tried to propose a solution to enable entities to share interface files for identical parameters [2]. But our solution didn't convince Tejun, and we got stuck. Fortunately, now cfq has gone with legacy blk, so there is no need any longer for prefixes in (the never used) bfq names. In view of this fact, here's an alternative patch, which simply removes these prefixes, thereby enabling legacy code to truly use the proportional share policy in blk-mq. This postpones the problem of sharing common interface files, to when, e.g., some new proportional-share policy gets proposed. Paolo [1] https://github.com/systemd/systemd/issues/7057 [2] https://lwn.net/ml/linux-block/20181119103424.3853-1-paolo.valente@xxxxxxxxxx/ Angelo Ruocco (1): block, bfq: delete "bfq" prefix from cgroup filenames block/bfq-cgroup.c | 46 +++++++++++++++++++++++----------------------- 1 file changed, 23 insertions(+), 23 deletions(-) -- 2.20.1
