On Fri, 12 May 2023 01:53:11 PDT (-0700), alexghiti@xxxxxxxxxxxx wrote:
riscv used to allow direct access to cycle/time/instret counters, bypassing the perf framework, this patchset intends to allow the user to mmap any counter when accessed through perf. But we can't break the existing behaviour so we introduce a sysctl perf_user_access like arm64 does, which defaults to the legacy mode described above. *Note* that there are still ongoing discussions around which mode should be the default mode with distro people. base-commit-tag: v6.3 Changes in v2: - Split into smaller patches, way better! - Add RB from Conor - Simplify the way we checked riscv architecture - Fix race mmap and other thread running on other cpus - Use hwc when available - Set all userspace access flags in event_init, too cumbersome to handle sysctl changes - Fix arch_perf_update_userpage for pmu other than riscv-pmu by renaming pmu driver - Fixed kernel test robot build error - Fixed documentation (Andrew and Bagas) - perf testsuite passes mmap tests in all 3 modes Alexandre Ghiti (10): perf: Fix wrong comment about default event_idx include: riscv: Fix wrong include guard in riscv_pmu.h riscv: Make legacy counter enum match the HW numbering drivers: perf: Rename riscv pmu driver riscv: Prepare for user-space perf event mmap support drivers: perf: Implement perf event mmap support in the legacy backend drivers: perf: Implement perf event mmap support in the SBI backend Documentation: admin-guide: Add riscv sysctl_perf_user_access tools: lib: perf: Implement riscv mmap support perf: tests: Adapt mmap-basic.c for riscv Documentation/admin-guide/sysctl/kernel.rst | 24 ++- arch/riscv/kernel/Makefile | 2 +- arch/riscv/kernel/perf_event.c | 74 ++++++++ drivers/perf/riscv_pmu.c | 41 ++++ drivers/perf/riscv_pmu_legacy.c | 37 +++- drivers/perf/riscv_pmu_sbi.c | 196 +++++++++++++++++++- include/linux/perf/riscv_pmu.h | 10 +- include/linux/perf_event.h | 3 +- tools/lib/perf/mmap.c | 65 +++++++ tools/perf/tests/mmap-basic.c | 4 +- 10 files changed, 435 insertions(+), 21 deletions(-) create mode 100644 arch/riscv/kernel/perf_event.c
It looks like there's a handful of outstanding review comments, so I'm going to mark this as changes requested in patchwork -- sorry if I missed a v3.
