Hi, Following changes based on the last round of review, I'm respinning this series for another RFC round. It is based on the v4.15-rc3 tag. I am now targeting the 4.16 merge window. This series contains: - Restartable sequences system call (x86 32/64, powerpc 32/64, arm 32), - CPU operation vector system call (x86 32/64, powerpc 32/64, arm 32). I have moved the membarrier patches to a different series. The main changes introduced in this updated version are: - Introducing a user-space "percpu-op.h" API, which wraps fast and slow paths into a single inline function, - Changes to the cpu_opv page pinning, making it robust with respect to concurrent PTE changes, - Fixed a rseq bug where the rseq_cs pointer was cleared too soon, causing hard-to-reproduce races triggered by NUMA page protection. - Extended rseq selftests to add a "compare twice" approach validating invaritants, which catches races more quickly and closer to the race. This updated series documents a major upside of the cpu_opv system call: it allows performing operations on remote per-cpu data (e.g. migration of memory between per-cpu memory pools, task migration across per-cpu work queues, or summing up and clearning per-cpu statistics counters) by simply passing the CPU number on which the operation must be performed as argument to the system call. Doing this without cpu_opv would require use of sched_setaffinity alongside with restartable sequences, which is not safe against CPU hot-unplug. Feedback is welcome! Thanks, Mathieu Boqun Feng (2): powerpc: Add support for restartable sequences powerpc: Wire up restartable sequences system call Mathieu Desnoyers (19): uapi headers: Provide types_32_64.h rseq: Introduce restartable sequences system call (v12) arm: Add restartable sequences support arm: Wire up restartable sequences system call x86: Add support for restartable sequences x86: Wire up restartable sequence system call sched: Implement push_task_to_cpu cpu_opv: Provide cpu_opv system call (v5) x86: Wire up cpu_opv system call powerpc: Wire up cpu_opv system call arm: Wire up cpu_opv system call selftests: lib.mk: Introduce OVERRIDE_TARGETS cpu_opv: selftests: Implement selftests (v6) rseq: selftests: Provide rseq library (v5) rseq: selftests: Provide percpu_op API rseq: selftests: Provide basic test rseq: selftests: Provide basic percpu ops test rseq: selftests: Provide parametrized tests rseq: selftests: Provide Makefile, scripts, gitignore MAINTAINERS | 20 + arch/Kconfig | 7 + arch/arm/Kconfig | 1 + arch/arm/kernel/signal.c | 7 + arch/arm/tools/syscall.tbl | 2 + arch/powerpc/Kconfig | 1 + arch/powerpc/include/asm/systbl.h | 2 + arch/powerpc/include/asm/unistd.h | 2 +- arch/powerpc/include/uapi/asm/unistd.h | 2 + arch/powerpc/kernel/signal.c | 3 + arch/x86/Kconfig | 1 + arch/x86/entry/common.c | 1 + arch/x86/entry/syscalls/syscall_32.tbl | 2 + arch/x86/entry/syscalls/syscall_64.tbl | 2 + arch/x86/kernel/signal.c | 6 + fs/exec.c | 1 + include/linux/sched.h | 109 ++ include/linux/syscalls.h | 6 + include/trace/events/rseq.h | 56 + include/uapi/linux/cpu_opv.h | 114 ++ include/uapi/linux/rseq.h | 150 +++ include/uapi/linux/types_32_64.h | 67 ++ init/Kconfig | 30 + kernel/Makefile | 2 + kernel/cpu_opv.c | 1078 +++++++++++++++++ kernel/fork.c | 2 + kernel/rseq.c | 358 ++++++ kernel/sched/core.c | 38 + kernel/sched/sched.h | 10 + kernel/sys_ni.c | 4 + tools/testing/selftests/Makefile | 2 + tools/testing/selftests/cpu-opv/.gitignore | 1 + tools/testing/selftests/cpu-opv/Makefile | 17 + .../testing/selftests/cpu-opv/basic_cpu_opv_test.c | 1258 ++++++++++++++++++++ tools/testing/selftests/cpu-opv/cpu-op.c | 352 ++++++ tools/testing/selftests/cpu-opv/cpu-op.h | 59 + tools/testing/selftests/lib.mk | 4 + tools/testing/selftests/rseq/.gitignore | 7 + tools/testing/selftests/rseq/Makefile | 37 + .../testing/selftests/rseq/basic_percpu_ops_test.c | 296 +++++ tools/testing/selftests/rseq/basic_test.c | 55 + tools/testing/selftests/rseq/param_test.c | 1163 ++++++++++++++++++ tools/testing/selftests/rseq/percpu-op.h | 163 +++ tools/testing/selftests/rseq/rseq-arm.h | 732 ++++++++++++ tools/testing/selftests/rseq/rseq-ppc.h | 688 +++++++++++ tools/testing/selftests/rseq/rseq-skip.h | 82 ++ tools/testing/selftests/rseq/rseq-x86.h | 1149 ++++++++++++++++++ tools/testing/selftests/rseq/rseq.c | 116 ++ tools/testing/selftests/rseq/rseq.h | 164 +++ tools/testing/selftests/rseq/run_param_test.sh | 130 ++ 50 files changed, 8558 insertions(+), 1 deletion(-) create mode 100644 include/trace/events/rseq.h create mode 100644 include/uapi/linux/cpu_opv.h create mode 100644 include/uapi/linux/rseq.h create mode 100644 include/uapi/linux/types_32_64.h create mode 100644 kernel/cpu_opv.c create mode 100644 kernel/rseq.c create mode 100644 tools/testing/selftests/cpu-opv/.gitignore create mode 100644 tools/testing/selftests/cpu-opv/Makefile create mode 100644 tools/testing/selftests/cpu-opv/basic_cpu_opv_test.c create mode 100644 tools/testing/selftests/cpu-opv/cpu-op.c create mode 100644 tools/testing/selftests/cpu-opv/cpu-op.h create mode 100644 tools/testing/selftests/rseq/.gitignore create mode 100644 tools/testing/selftests/rseq/Makefile create mode 100644 tools/testing/selftests/rseq/basic_percpu_ops_test.c create mode 100644 tools/testing/selftests/rseq/basic_test.c create mode 100644 tools/testing/selftests/rseq/param_test.c create mode 100644 tools/testing/selftests/rseq/percpu-op.h create mode 100644 tools/testing/selftests/rseq/rseq-arm.h create mode 100644 tools/testing/selftests/rseq/rseq-ppc.h create mode 100644 tools/testing/selftests/rseq/rseq-skip.h create mode 100644 tools/testing/selftests/rseq/rseq-x86.h create mode 100644 tools/testing/selftests/rseq/rseq.c create mode 100644 tools/testing/selftests/rseq/rseq.h create mode 100755 tools/testing/selftests/rseq/run_param_test.sh -- 2.11.0 -- To unsubscribe from this list: send the line "unsubscribe linux-api" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
