Hi, Considering it's already late in the 4.19 rc cycle, I'm submitting this patchset as RFC for 4.21 to give everyone plenty of time to provide feedback. This series contain: - rseq selftests (this could be 4.20 material): - Added reference counter within user-space __rseq_abi structure, for integration of rseq application/libraries with future use by glibc, - Adapt number of threads to the number of online cpus. - cpu_opv (4.21 material): - Implement push_task_to_cpu() (scheduler), - Introduce vm_map_user_ram()/vm_unmap_user_ram() (mm), - Provide is_vma_noncached() (mm), - Introduce cpu_opv system call, with vmap space limiting, - Wire up cpu_opv on x86, powerpc, arm, - Provide cpu_opv selftests. The cpu_opv system call covers the use-cases that rseq does not handle, namely single-stepping with debuggers, moving data between per-cpu data structures without interfering with cpu affinity masks, and using rseq from signal handlers nested between thread creation and rseq registration by glibc, or between rseq unregistration by glibc and thread teardown. Thanks, Mathieu Mathieu Desnoyers (16): rseq/selftests: Add reference counter to coexist with glibc rseq/selftests: Adapt number of threads to the number of detected cpus sched: Implement push_task_to_cpu (v2) mm: Introduce vm_map_user_ram, vm_unmap_user_ram mm: Provide is_vma_noncached cpu_opv: Provide cpu_opv system call (v8) cpu_opv: limit amount of virtual address space used by cpu_opv x86: Wire up cpu_opv system call powerpc: Wire up cpu_opv system call arm: Wire up cpu_opv system call cpu-opv/selftests: Provide cpu-op library cpu-opv/selftests: Provide basic test cpu-opv/selftests: Provide percpu_op API cpu-opv/selftests: Provide basic percpu ops test cpu-opv/selftests: Provide parametrized tests cpu-opv/selftests: Provide Makefile, scripts, gitignore MAINTAINERS | 8 + arch/arm/tools/syscall.tbl | 1 + arch/powerpc/include/asm/systbl.h | 1 + arch/powerpc/include/uapi/asm/unistd.h | 1 + arch/x86/entry/syscalls/syscall_32.tbl | 1 + arch/x86/entry/syscalls/syscall_64.tbl | 1 + include/linux/mm.h | 24 + include/linux/syscalls.h | 3 + include/linux/vmalloc.h | 4 + include/uapi/linux/cpu_opv.h | 114 ++ init/Kconfig | 17 + kernel/Makefile | 1 + kernel/cpu_opv.c | 1190 +++++++++++++++++ kernel/sched/core.c | 42 + kernel/sched/sched.h | 9 + kernel/sys_ni.c | 1 + kernel/sysctl.c | 15 + mm/vmalloc.c | 64 + tools/testing/selftests/Makefile | 1 + tools/testing/selftests/cpu-opv/.gitignore | 6 + tools/testing/selftests/cpu-opv/Makefile | 39 + .../testing/selftests/cpu-opv/basic_cpu_opv_test.c | 1362 ++++++++++++++++++++ .../selftests/cpu-opv/basic_percpu_ops_test.c | 295 +++++ tools/testing/selftests/cpu-opv/cpu-op.c | 353 +++++ tools/testing/selftests/cpu-opv/cpu-op.h | 42 + tools/testing/selftests/cpu-opv/param_test.c | 1187 +++++++++++++++++ tools/testing/selftests/cpu-opv/percpu-op.h | 151 +++ tools/testing/selftests/cpu-opv/run_param_test.sh | 134 ++ tools/testing/selftests/rseq/rseq.c | 32 +- tools/testing/selftests/rseq/run_param_test.sh | 7 +- 30 files changed, 5096 insertions(+), 10 deletions(-) create mode 100644 include/uapi/linux/cpu_opv.h create mode 100644 kernel/cpu_opv.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/basic_percpu_ops_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/cpu-opv/param_test.c create mode 100644 tools/testing/selftests/cpu-opv/percpu-op.h create mode 100755 tools/testing/selftests/cpu-opv/run_param_test.sh -- 2.11.0