Hi, here is the V2 of this patch series. Let me rephrase the description of the series, in view of the fact that CFQ will be gone with legacy block. The current implementation of cgroups doesn't allow two or more entities, e.g., I/O schedulers, to share the same files. Thus, to enable people to set group weights with BFQ, I resorted to making BFQ create its own version of the same interface files used by CFQ (before going away with legacy block), by prepending a bfq prefix. Actually, no legacy code uses these different names, or is likely to do so. Having these two sets of names is simply a source of confusion, as pointed out also, e.g., by Lennart Poettering (CCed here), and acknowledged by Tejun [2]. In [1] we agreed on a solution that solves this problem, by actually making it possible to share cgroups files. Both writing to and reading from a shared file trigger the appropriate operation for each of the entities that share the file. In particular, in case of reading, - if all entities produce the same output, the this common output is shown only once; - if the outputs differ, then every per-entity output is shown, followed by the name of the entity that produced that output. With this solution, legacy code that, e.g., sets group weights, just works, regardless of the I/O scheduler actually implementing proportional share. But note that this extension is not restricted to only blkio/io. The general group interface now enables files to be shared among multiple entities of any kind. (I have also added a patch to fix some clerical errors in bfq doc, which I found while making the latter consistent with the new interface.) CHANGES FROM V1: - Removed patch that introduced a function to only find kernfs nodes, without increasing ref counters - Changed commit messages and BFQ documentation, to comply with the fact that there won't be CFQ any longer Thanks, Paolo Angelo Ruocco (5): cgroup: link cftypes of the same subsystem with the same name cgroup: add owner name to cftypes block, bfq: align min and default weights with the old cfq default cgroup: make all functions of all cftypes be invoked block, throttle: allow sharing cgroup statistic files Paolo Valente (5): cgroup: add hook seq_show_cft with also the owning cftype as parameter block, cgroup: pass cftype to functions that need to use it block, bfq: use standard file names for the proportional-share policy doc, bfq-iosched: fix a few clerical errors doc, bfq-iosched: make it consistent with the new cgroup interface Documentation/block/bfq-iosched.txt | 34 ++--- block/bfq-cgroup.c | 148 +++++++++++++------- block/bfq-iosched.h | 4 +- block/blk-cgroup.c | 22 +-- block/blk-throttle.c | 24 ++-- include/linux/blk-cgroup.h | 10 +- include/linux/cgroup-defs.h | 14 +- include/linux/cgroup.h | 13 ++ kernel/cgroup/cgroup.c | 262 +++++++++++++++++++++++++++++------- 9 files changed, 390 insertions(+), 141 deletions(-) -- 2.16.1
