linux-kernel - [PATCH V3 00/10] perf: Expand perf_branch

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Message-Id: <20220314055857.125421-1-anshuman.khandual@arm.com>
Date:   Mon, 14 Mar 2022 11:28:47 +0530
From:   Anshuman Khandual <anshuman.khandual@....com>
To:     linux-kernel@...r.kernel.org, linux-perf-users@...r.kernel.org,
        peterz@...radead.org, acme@...nel.org
Cc:     Anshuman Khandual <anshuman.khandual@....com>,
        Suzuki Poulose <suzuki.poulose@....com>,
        James Clark <james.clark@....com>,
        Ingo Molnar <mingo@...hat.com>,
        Mark Rutland <mark.rutland@....com>,
        Alexander Shishkin <alexander.shishkin@...ux.intel.com>,
        Jiri Olsa <jolsa@...hat.com>,
        Namhyung Kim <namhyung@...nel.org>,
        Thomas Gleixner <tglx@...utronix.de>,
        Will Deacon <will@...nel.org>,
        linux-arm-kernel@...ts.infradead.org
Subject: [PATCH V3 00/10] perf: Expand perf_branch_entry

Branch Record Buffer Extension (BRBE) implementation on arm64 captures more
branch type classification which cannot be accommodated in the current perf
branch record format via perf_branch_entry.type element (4 bit field). Also
it captures privilege information which does not have a corresponding slot
in perf_branch_entry. This series expands struct perf_branch_entry, to meet
both these requirements without breaking the existing user space ABI for
perf tools.

All architecture specific branch types added via perf_branch_entry.new_type
field in [PATCH 3/4] will be used in BRBE implementation on arm64 platform
later on with the following map.

#ifdef CONFIG_ARM64
#define PERF_BR_FIQ		PERF_BR_NEW_ARCH_1
#define PERF_BR_DEBUG_HALT	PERF_BR_NEW_ARCH_2
#define PERF_BR_DEBUG_EXIT	PERF_BR_NEW_ARCH_3
#define PERF_BR_DEBUG_INST	PERF_BR_NEW_ARCH_4
#define PERF_BR_DEBUG_DATA	PERF_BR_NEW_ARCH_5
#endif

This actually combines following patches and series into a single series.

- https://lore.kernel.org/all/1642998653-21377-12-git-send-email-anshuman.khandual@arm.com/
- https://lore.kernel.org/all/1643348653-24367-1-git-send-email-anshuman.khandual@arm.com/
- https://lore.kernel.org/all/1645681014-3346-1-git-send-email-anshuman.khandual@arm.com/

This series applies on v5.17-rc8

perf API

The series being applied

- Clean : tools/perf/check-headers.sh
- Clean : diff -u tools/include/uapi/linux/perf_event.h include/uapi/linux/perf_event.h

Todo

- Update perf report tool to process PERF_BR_EXTEND_ABI (when available),
  then fetch and report branch types from perf_branch_entry.new_type field.

References

- BRBE captured branch record information

https://developer.arm.com/documentation/ddi0601/2021-12/AArch64-Registers/BRBINF-n--EL1--Branch-Record-Buffer-Information-Register--n-?lang=en

- BRBE based perf branch stack implementation on arm64 platform

https://lore.kernel.org/all/1642998653-21377-1-git-send-email-anshuman.khandual@arm.com/

Changes in V3:

- Fixed small typo s/privillege/privilege in include/uapi/linux/perf_event.h
- Added PRIV_SHIFT in __p_branch_sample_type()
- Added arm64 platform override of the new arch specific branch types
- Renamed s/PERF_BR_XXX/PERF_BR_PRIV_XXX/ for privilege level branch types
- Added PERF_BR_PRIV_UNKNOWN as the starting value
- Expanded perf_branch_entry.priv into a 3 bits field 

Changes in V2:

https://lore.kernel.org/all/20220309033642.144769-1-anshuman.khandual@arm.com/

Cc: Suzuki Poulose <suzuki.poulose@....com>
Cc: James Clark <james.clark@....com>
Cc: Peter Zijlstra <peterz@...radead.org>
Cc: Ingo Molnar <mingo@...hat.com>
Cc: Arnaldo Carvalho de Melo <acme@...nel.org>
Cc: Mark Rutland <mark.rutland@....com>
Cc: Alexander Shishkin <alexander.shishkin@...ux.intel.com>
Cc: Jiri Olsa <jolsa@...hat.com>
Cc: Namhyung Kim <namhyung@...nel.org>
Cc: Thomas Gleixner <tglx@...utronix.de>
Cc: Will Deacon <will@...nel.org>
Cc: linux-arm-kernel@...ts.infradead.org
Cc: linux-perf-users@...r.kernel.org
Cc: linux-kernel@...r.kernel.org

Anshuman Khandual (10):
  perf: Add irq and exception return branch types
  perf: Add system error and not in transaction branch types
  perf: Extend branch type classification
  perf: Capture branch privilege information
  perf: Add PERF_BR_NEW_ARCH_[N] map for BRBE on arm64 platform
  perf/tools: Add irq and exception return branch types
  perf/tools: Add system error and not in transaction branch types
  perf/tools: Extend branch type classification
  perf/tools: Add branch privilege information request flag
  perf/tools: Add PERF_BR_NEW_ARCH_[N] map for BRBE on arm64 platform

 arch/x86/events/intel/lbr.c               |  6 ++--
 include/uapi/linux/perf_event.h           | 40 ++++++++++++++++++++++-
 tools/include/uapi/linux/perf_event.h     | 40 ++++++++++++++++++++++-
 tools/perf/Documentation/perf-record.txt  |  1 +
 tools/perf/util/branch.c                  |  7 +++-
 tools/perf/util/parse-branch-options.c    |  1 +
 tools/perf/util/perf_event_attr_fprintf.c |  2 +-
 7 files changed, 90 insertions(+), 7 deletions(-)

-- 
2.25.1