Re: [Ksummit-discuss] [MAINTAINER TOPIC] ABI feature gates?

[Stephen Rothwell <sfr@canb.auug.org.au>]

Hi Ted,

On Thu, 3 Aug 2017 22:26:39 -0400 Theodore Ts'o <tytso@mit.edu> wrote:
>
> One way that we could try to make things better is by having some kind
> of semi-automated system which monitors changes in include/uapi/*.h in
> linux-next.  Unfortunately there will be a lot of false negatives, so
> it's going to require a human to figure out which of the changes
> represent new/changed API's, and which are just cleanups /
> rearragements.  (We could try to see if we could train a Machine
> Learning model --- but even if we can make a some nueral nets play Go,
> I'm personally dubious this is something that ML would be successful
> at.  I might be pleasantly surprised, though, if someone wanted to
> give it a try.  :-)

OK, so this is what we have so far in linux-next:

$ git log --no-merges --pretty="%h %s" stable..next-20170803 include/uapi
9aa302aaede8 membarrier: Expedited private command
b3a88f222ae1 drm/msm: Add a parameter query for the number of ringbuffers
7f1779fd071b drm/msm: Implement per-submitqueue fences
20ab08455d3c drm/msm: Add per-instance submit queues
80fe969b5d50 uapi: fix linux/sysctl.h userspace compilation errors
4edc19eeeee3 mm: userfaultfd: add feature to request for a signal delivery
0d33bdf5ea6c mm: shm: use new hugetlb size encoding definitions
b217edddf5c2 mm: arch: consolidate mmap hugetlb size encodings
21d75dd8e83d mm: hugetlb: define system call hugetlb size encodings in single file
cdbc78ba7026 drm/msm: Remove __user from __u64 data types
db1689aa61bd drm: Create a format/modifier blob
e6fc3b68558e drm: Plumb modifiers through plane init
bb7c19f96012 tcp: add related fields into SCM_TIMESTAMPING_OPT_STATS
3282e65558b3 tcp: remove unused mib counters
615095752100 netfilter: nf_tables: Allow object names of up to 255 chars
387454901bd6 netfilter: nf_tables: Allow set names of up to 255 chars
b7263e071aba netfilter: nf_tables: Allow chain name of up to 255 chars
e46abbcc05aa netfilter: nf_tables: Allow table names of up to 255 chars
e62e484df049 net sched actions: add time filter for action dumping
90825b23a887 net sched actions: dump more than TCA_ACT_MAX_PRIO actions per batch
64c83d837329 net netlink: Add new type NLA_BITFIELD32
1a5f3da20bd9 net: ethtool: add support for forward error correction modes
ca1136c99b66 blktrace: export cgroup info in trace
f30994622b2b drm/vc4: Add an ioctl for labeling GEM BOs for summary stats
67cbe3532c2c RDMA/qedr: notify user application of supported WIDs
ad84dad2160d RDMA/qedr: notify user application if DPM is supported
cc731525f26a signal: Remove kernel interal si_code magic
d08477aa975e fcntl: Don't use ambiguous SIG_POLL si_codes
3078f5f1bd8b IB/mlx4: Add support for RSS QP
b8d46ca03506 IB/mlx4: Add support for WQ indirection table related verbs
400b1ebcfe31 IB/mlx4: Add support for WQ related verbs
ea30b966f7dd IB/mlx4: Add inline-receive support
2dee0e545894 IB/uverbs: Enable QP creation with a given source QP number
784b4e612d42 netfilter: nf_tables: Attach process info to NFT_MSG_NEWGEN notifications
ddc6c70f07bb rxrpc: Move the packet.h include file into net/rxrpc/
727f8914477e rxrpc: Expose UAPI definitions to userspace
eb0baf8a0d92 perf/core: Define the common branch type classification
6b2bbb08747a media: cec: rework the cec event handling
6303d97873d3 media: linux/cec.h: add pin monitoring API support
fc60a8b675bd tty: serial: owl: Implement console driver
97f91a7cf04f bpf: add bpf_redirect_map helper routine
546ac1ffb70d bpf: add devmap, a map for storing net device references
814abfabef3c xdp: add bpf_redirect helper function
66bf97967726 annotate RWF_... flags
6545135a5ed2 drm/qxl: fix __user annotations

Some of these are just fixing bugs or moving things around.  I wonder
where we can go from here?  Does every change to a uapi file need a
corresponding documentation and man pages update?  Do we dare try doing
(shock! horror!) design before implementation?  ;-)

The, of course, there is the whole sysfs and tracing mess :-(
-- 
Cheers,
Stephen Rothwell