From: Alexandre Ghiti <alexghiti@rivosinc.com>
To: "Jonathan Corbet" <corbet@lwn.net>,
"Peter Zijlstra" <peterz@infradead.org>,
"Ingo Molnar" <mingo@redhat.com>,
"Arnaldo Carvalho de Melo" <acme@kernel.org>,
"Mark Rutland" <mark.rutland@arm.com>,
"Alexander Shishkin" <alexander.shishkin@linux.intel.com>,
"Jiri Olsa" <jolsa@kernel.org>,
"Namhyung Kim" <namhyung@kernel.org>,
"Ian Rogers" <irogers@google.com>,
"Paul Walmsley" <paul.walmsley@sifive.com>,
"Palmer Dabbelt" <palmer@dabbelt.com>,
"Albert Ou" <aou@eecs.berkeley.edu>,
"Atish Patra" <atishp@atishpatra.org>,
"Anup Patel" <anup@brainfault.org>,
"Will Deacon" <will@kernel.org>, "Rob Herring" <robh@kernel.org>,
"Andrew Jones" <ajones@ventanamicro.com>,
"Rémi Denis-Courmont" <remi@remlab.net>,
linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-perf-users@vger.kernel.org,
linux-riscv@lists.infradead.org,
linux-arm-kernel@lists.infradead.org
Cc: Alexandre Ghiti <alexghiti@rivosinc.com>
Subject: [PATCH v4 00/10] riscv: Allow userspace to directly access perf counters
Date: Thu, 27 Jul 2023 16:14:18 +0200 [thread overview]
Message-ID: <20230727141428.962286-1-alexghiti@rivosinc.com> (raw)
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.
**Important**: The default mode is now user access through perf only, not
the legacy so some applications will break. However, we introduce a sysctl
perf_user_access like arm64 does, which will allow to switch to the legacy
mode described above.
This version needs openSBI v1.3 *and* a kernel fix that went upstream lately
(https://lore.kernel.org/lkml/20230616114831.3186980-1-maz@kernel.org/T/).
base-commit-tag: v6.5-rc1
Changes in v5:
- Fix typo from Atish
- Add RB from Atish and Andrew
- Improve cover letter and patch 7 commit log to explain why we made the
choice to break userspace for security reasons, thanks Atish and Rémi
- Rebase on top of v6.5-rc1
Changes in v4:
- Fixed some nits in riscv_pmu_sbi.c thanks to Andrew
- Fixed the documentation thanks to Andrew
- Added RB from Andrew \o/
Changes in v3:
- patch 1 now contains the ref to the faulty commit (no Fixes tag as it is only a comment), as Andrew suggested
- Removed RISCV_PMU_LEGACY_TIME from patch 3, as Andrew suggested
- Rename RISCV_PMU_PDEV_NAME to "riscv-pmu-sbi", patch4 is just cosmetic now, as Andrew suggested
- Removed a few useless (and wrong) comments, as Andrew suggested
- Simplify arch_perf_update_userpage code, as Andrew suggested
- Documentation now mentions that time CSR is *always* accessible, whatever the mode, as suggested by Andrew
- Removed CYCLEH reference and add TODO for rv32 support, as suggested by Atish
- Do not rename the pmu instance as Atish suggested
- Set pmc_width only if rdpmc is enabled and CONFIG_RISCV_PMU is set and the event is a hw event
- Move arch_perf_update_userpage https://lore.kernel.org/lkml/20230616114831.3186980-1-maz@kernel.org/T/
- **Switch to user mode access by default**
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 sbi 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 | 27 ++-
drivers/perf/riscv_pmu.c | 113 +++++++++++
drivers/perf/riscv_pmu_legacy.c | 28 ++-
drivers/perf/riscv_pmu_sbi.c | 196 +++++++++++++++++++-
include/linux/perf/riscv_pmu.h | 12 +-
include/linux/perf_event.h | 3 +-
tools/lib/perf/mmap.c | 65 +++++++
tools/perf/tests/mmap-basic.c | 4 +-
8 files changed, 428 insertions(+), 20 deletions(-)
--
2.39.2
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next reply other threads:[~2023-07-27 14:14 UTC|newest]
Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-07-27 14:14 Alexandre Ghiti [this message]
2023-07-27 14:14 ` [PATCH v4 01/10] perf: Fix wrong comment about default event_idx Alexandre Ghiti
2023-07-27 14:14 ` [PATCH v4 02/10] include: riscv: Fix wrong include guard in riscv_pmu.h Alexandre Ghiti
2023-07-27 14:14 ` [PATCH v4 03/10] riscv: Make legacy counter enum match the HW numbering Alexandre Ghiti
2023-07-27 14:14 ` [PATCH v4 04/10] drivers: perf: Rename riscv pmu sbi driver Alexandre Ghiti
2023-07-27 14:14 ` [PATCH v4 05/10] riscv: Prepare for user-space perf event mmap support Alexandre Ghiti
2023-07-27 14:14 ` [PATCH v4 06/10] drivers: perf: Implement perf event mmap support in the legacy backend Alexandre Ghiti
2023-07-27 14:14 ` [PATCH v4 07/10] drivers: perf: Implement perf event mmap support in the SBI backend Alexandre Ghiti
2023-07-27 14:14 ` [PATCH v4 08/10] Documentation: admin-guide: Add riscv sysctl_perf_user_access Alexandre Ghiti
2023-07-27 14:14 ` [PATCH v4 09/10] tools: lib: perf: Implement riscv mmap support Alexandre Ghiti
2023-07-28 17:52 ` Ian Rogers
2023-07-31 10:15 ` Alexandre Ghiti
2023-07-31 10:27 ` Alexandre Ghiti
2023-07-31 15:10 ` Ian Rogers
2023-07-31 16:06 ` Alexandre Ghiti
2023-07-31 16:46 ` Ian Rogers
2023-07-31 19:47 ` Matthew Wilcox
2023-07-31 21:07 ` Jessica Clarke
2023-08-01 7:09 ` Alexandre Ghiti
2023-07-31 19:37 ` Jessica Clarke
2023-07-27 14:14 ` [PATCH v4 10/10] perf: tests: Adapt mmap-basic.c for riscv Alexandre Ghiti
2023-07-28 17:54 ` Ian Rogers
2023-07-29 7:38 ` Andrew Jones
-- strict thread matches above, loose matches on Subject: below --
2023-07-03 12:46 [PATCH v4 00/10] riscv: Allow userspace to directly access perf counters Alexandre Ghiti
2023-07-14 9:07 ` Atish Patra
2023-07-17 13:35 ` Rémi Denis-Courmont
2023-07-17 23:22 ` Atish Patra
2023-07-18 17:06 ` Rémi Denis-Courmont
2023-07-18 18:45 ` Atish Patra
2023-07-18 19:04 ` Rémi Denis-Courmont
2023-07-18 22:48 ` Atish Patra
2023-07-19 14:45 ` Rémi Denis-Courmont
2023-07-19 17:14 ` Atish Patra
2023-07-20 9:13 ` Alexandre Ghiti
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