[PATCH v0.9 0/6] sched,mm,x86/uaccess: implement User Managed Concurrency Groups

[Peter Oskolkov]

User Managed Concurrency Groups (UMCG) is an M:N threading
subsystem/toolkit that lets user space application developers implement
in-process user space schedulers.

This patchset is v0.8 rebased on top of the current tip/sched/core,
with a fix in umcg_update_state of an issue reported by Tao Zhou.

Key changes from patchset v0.7:
https://lore.kernel.org/all/20211012232522.714898-1-posk@xxxxxxxxxx/:

- added libumcg tools/lib/umcg;
- worker "wakeup" is reworked so that it is now purely a userspace op,
  instead of waking the thread in order for it to block on return
  to the userspace immediately;
- a couple of minor fixes and refactorings.

These big things remain to be addressed (in no particular order):
- support tracing/debugging
- make context switches faster (see umcg_do_context_switch in umcg.c)
- support other architectures
- cleanup and post selftests in tools/testing/selftests/umcg/
- allow cross-mm wakeups (securely)


Peter Oskolkov (6):
  sched/umcg: add WF_CURRENT_CPU and externise ttwu
  mm, x86/uaccess: add userspace atomic helpers
  sched/umcg: implement UMCG syscalls
  sched/umcg, lib/umcg: implement libumcg
  sched/umcg: add Documentation/userspace-api/umcg.txt
  sched/umcg, lib/umcg: add tools/lib/umcg/libumcg.txt

 Documentation/userspace-api/umcg.txt   |  598 ++++++++++++
 arch/x86/entry/syscalls/syscall_64.tbl |    2 +
 arch/x86/include/asm/uaccess_64.h      |   93 ++
 fs/exec.c                              |    1 +
 include/linux/sched.h                  |   71 ++
 include/linux/syscalls.h               |    3 +
 include/linux/uaccess.h                |   46 +
 include/uapi/asm-generic/unistd.h      |    7 +-
 include/uapi/linux/umcg.h              |  137 +++
 init/Kconfig                           |   10 +
 kernel/entry/common.c                  |    4 +-
 kernel/exit.c                          |    5 +
 kernel/sched/Makefile                  |    1 +
 kernel/sched/core.c                    |   12 +-
 kernel/sched/fair.c                    |    4 +
 kernel/sched/sched.h                   |   15 +-
 kernel/sched/umcg.c                    |  949 +++++++++++++++++++
 kernel/sys_ni.c                        |    4 +
 mm/maccess.c                           |  264 ++++++
 tools/lib/umcg/.gitignore              |    4 +
 tools/lib/umcg/Makefile                |   11 +
 tools/lib/umcg/libumcg.c               | 1201 ++++++++++++++++++++++++
 tools/lib/umcg/libumcg.h               |  299 ++++++
 tools/lib/umcg/libumcg.txt             |  438 +++++++++
 24 files changed, 4167 insertions(+), 12 deletions(-)
 create mode 100644 Documentation/userspace-api/umcg.txt
 create mode 100644 include/uapi/linux/umcg.h
 create mode 100644 kernel/sched/umcg.c
 create mode 100644 tools/lib/umcg/.gitignore
 create mode 100644 tools/lib/umcg/Makefile
 create mode 100644 tools/lib/umcg/libumcg.c
 create mode 100644 tools/lib/umcg/libumcg.h
 create mode 100644 tools/lib/umcg/libumcg.txt


base-commit: cb0e52b7748737b2cf6481fdd9b920ce7e1ebbdf
--
2.25.1