RSEQ node id and virtual cpu id extensions [LWN.net]

From:		Mathieu Desnoyers <mathieu.desnoyers-AT-efficios.com>
To:		Peter Zijlstra <peterz-AT-infradead.org>
Subject:		[RFC PATCH v2 00/11] RSEQ node id and virtual cpu id extensions
Date:		Fri, 18 Feb 2022 16:06:22 -0500
Message-ID:		<20220218210633.23345-1-mathieu.desnoyers@efficios.com>
Cc:		linux-kernel-AT-vger.kernel.org, Thomas Gleixner <tglx-AT-linutronix.de>, "Paul E . McKenney" <paulmck-AT-kernel.org>, Boqun Feng <boqun.feng-AT-gmail.com>, "H . Peter Anvin" <hpa-AT-zytor.com>, Paul Turner <pjt-AT-google.com>, linux-api-AT-vger.kernel.org, Christian Brauner <christian.brauner-AT-ubuntu.com>, Florian Weimer <fw-AT-deneb.enyo.de>, David.Laight-AT-ACULAB.COM, carlos-AT-redhat.com, Peter Oskolkov <posk-AT-posk.io>, Mathieu Desnoyers <mathieu.desnoyers-AT-efficios.com>
Archive-link:		Article

Hi,

I'm sending this series for feedback. There appears to be a lot of
interest in the virtual cpu id feature for use in user-space memory
allocators (e.g. glibc malloc), so I am sending this out as RFC.

The most interesting patch in here is "sched: Introduce per memory space
current virtual cpu id". So if you want to jump to the meat, go
immediately to that patch.

This series is based on the tip tree core/sched branch [1] at commit
ed3b362d54f0 ("sched/isolation: Split housekeeping cpumask per isolation
features").

Feedback is welcome!

Thanks,

Mathieu

[1] https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git/

Mathieu Desnoyers (11):
  rseq: Introduce feature size and alignment ELF auxiliary vector
    entries
  rseq: Introduce extensible rseq ABI
  rseq: extend struct rseq with numa node id
  selftests/rseq: Use ELF auxiliary vector for extensible rseq
  selftests/rseq: Implement rseq numa node id field selftest
  lib: invert _find_next_bit source arguments
  lib: implement find_{first,next}_{zero,one}_and_zero_bit
  cpumask: implement cpumask_{first,next}_{zero,one}_and_zero
  sched: Introduce per memory space current virtual cpu id
  rseq: extend struct rseq with per memory space vcpu id
  selftests/rseq: Implement rseq vm_vcpu_id field support

 fs/binfmt_elf.c                           |   5 +
 fs/exec.c                                 |   4 +
 include/linux/cpumask.h                   |  94 ++++++
 include/linux/find.h                      | 123 +++++++-
 include/linux/mm.h                        |  25 ++
 include/linux/mm_types.h                  | 111 +++++++
 include/linux/sched.h                     |   9 +
 include/trace/events/rseq.h               |   4 +-
 include/uapi/linux/auxvec.h               |   2 +
 include/uapi/linux/rseq.h                 |  22 ++
 init/Kconfig                              |   4 +
 kernel/fork.c                             |  15 +-
 kernel/ptrace.c                           |   2 +-
 kernel/rseq.c                             |  60 +++-
 kernel/sched/core.c                       |  82 +++++
 kernel/sched/deadline.c                   |   3 +
 kernel/sched/debug.c                      |  13 +
 kernel/sched/fair.c                       |   1 +
 kernel/sched/rt.c                         |   2 +
 kernel/sched/sched.h                      | 364 ++++++++++++++++++++++
 kernel/sched/stats.c                      |  16 +-
 lib/find_bit.c                            |  17 +-
 tools/include/linux/find.h                |   9 +-
 tools/lib/find_bit.c                      |  17 +-
 tools/testing/selftests/rseq/basic_test.c |   5 +
 tools/testing/selftests/rseq/rseq-abi.h   |  22 ++
 tools/testing/selftests/rseq/rseq.c       |  86 ++++-
 tools/testing/selftests/rseq/rseq.h       |  46 ++-
 28 files changed, 1106 insertions(+), 57 deletions(-)

-- 
2.17.1