Re: [Patch v10 00/10] Perf tools: Support eGPRs/SSP/SIMD registers sampling

[Arnaldo Carvalho de Melo]

On Thu, Sep 10, 2026 at 10:59:51AM +0800, Mi, Dapeng wrote:
> Peter queued the dependent perf patches into the tip perf/core tree.
 
> https://lore.kernel.org/all/20260824082731.1013973-1-dapeng1.mi@xxxxxxxxxxxxxxx/
 
> But since there are UAPI changes, these perf-tools patches would lead to
> errors without the corresponding perf patches. 
 
> @Arnaldo, @Namhyung, @Ian how would we handle such kind of dependency
> issues generally? Wait for the dependent perf patches merged into mainline
> and then merge the perf-tools patches?

That would slow down development, if it made perf kernel upstream, even
if not yet to Linus, we can update the header in perf-tools-next, the
check_headers script will warn about it, but now it is not running by
default so no distracting warning and if when we decide to run it we got
advanced warning that it will take some time to sort out, i.e. when the
perf kernel UAPI header hits upstream and perf-tools-next merges with
it.

So send perf kernel patches to Peter and the tooling ones to me and
Namhyung.

- Arnaldo
 
> Thanks.
> 
> 
> On 7/21/2026 3:26 PM, Dapeng Mi wrote:
> > Patch layout:
> > - Patches 1-2: Fix two bugs in DWARF register bounds checking and event
> >   attribute printing/swapping.
> > - Patches 3-4: Sync tools and perf headers with the kernel sources.
> > - Patches 5-8: Add SIMD/eGPR/SSP sampling and dump support.
> > - Patches 9-10: Add unit tests for SIMD/eGPR/SSP sampling.
> >
> > Changes since v9:
> > - Patch 05/10: Fix the issue that cpu-clock/task-clock fails to sample
> >   GPRs.
> > - Patch 06/10: Ensure sample_intr_{pred|vec}_regs and
> >   sample_user_{pred|vec}_regs to keep identical if both are set since
> >   they share sample_{pred|vec}_reg_qwords.
> >
> > Changes since v8:
> > - Patch 01/10: Fix incorrect DWARF register bounds checking.
> > - Patch 02/10: Add missing event attribute printing and swapping support
> >   (Sashiko).
> > - Patch 07/10: Remove dead code ([idx++]) in SIMD register dumping
> >   (Sashiko).
> > - Patch 08/10: Restore the original x86 libdw_frame_nregs value (17), as
> >   libdw still lacks x86 SIMD/eGPR support (Ian).
> > - Patch 09/10: Add x86 eGPR/SSP sampling unit tests (Ian).
> > - Patch 10/10: Add x86 SIMD register sampling unit tests (Ian).
> >
> > Changes since v7:
> > - Address Sashiko's comments including,
> >   * documents are not update availably; SIMD registers bitmask may be
> >     overwritten by shorter mask; u16 type in sample meta-data break the
> >     cross-endian conversion, etc.
> > - Add SIMD/eGPRs/SSP support in dwarf-regs (Ian).
> > - Misc enhancements.
> >
> > Changes since v6:
> > - Address Ian's comments including,
> >   * Add more comments for newly added register indexes (patch 1/4).
> >   * Several minor enhancements in patch 4/4.
> > - Limit dwarf minimal regs to legacy GPRs (excluding APX eGPRs)
> >   (patch 2/4).
> >
> > Changes since v5:
> > - Split the sampling support for eGPRs/SSP registers and SIMD registers
> >   into 2 patches.
> > - Address Ian's comments including,
> >   * Convert the architecture dependent functions into regular
> >     architectural independent functions, like whatperf_reg_name() does.
> >   * Refine the functions name to represent what the functions really do.
> >   * Add comments for some key functions arguments.
> >   * Misc enhancements.
> >
> > This patch-set adds sampling support for x86 eGPRs/SSP/SIMD registers in
> > perf tools base on the corresponding sampling support for eGPRs/SSP/SIMD
> > registers in kernel[1]. In versions before v6, these perf-tools patches
> > are integrated as a whole patch-set with the kernel patches, but it's
> > split and posted to an independent perf-tools patch-set for convenient
> > review.
> >
> > History:
> > v9: https://lore.kernel.org/all/20260706023444.3067660-1-dapeng1.mi@xxxxxxxxxxxxxxx/
> > v8: https://lore.kernel.org/all/20260529082451.591783-1-dapeng1.mi@xxxxxxxxxxxxxxx/
> > v7: https://lore.kernel.org/all/20260324005706.3778057-1-dapeng1.mi@xxxxxxxxxxxxxxx/
> > v6: https://lore.kernel.org/all/20260209083514.2225115-1-dapeng1.mi@xxxxxxxxxxxxxxx/
> > v5: https://lore.kernel.org/all/20251203065500.2597594-1-dapeng1.mi@xxxxxxxxxxxxxxx/
> > v4: https://lore.kernel.org/all/20250925061213.178796-1-dapeng1.mi@xxxxxxxxxxxxxxx/
> > v3: https://lore.kernel.org/lkml/20250815213435.1702022-1-kan.liang@xxxxxxxxxxxxxxx/
> > v2: https://lore.kernel.org/lkml/20250626195610.405379-1-kan.liang@xxxxxxxxxxxxxxx/
> > v1: https://lore.kernel.org/lkml/20250613134943.3186517-1-kan.liang@xxxxxxxxxxxxxxx/
> >
> > Ref:
> > [1] Kernel patches of supporting eGPRs/SSP/SIMD registers sampling:
> > https://lore.kernel.org/all/20260721062506.3745816-1-dapeng1.mi@xxxxxxxxxxxxxxx/
> >
> > Dapeng Mi (10):
> >   perf dwarf-regs: Fix DWARF register index bounds check
> >   perf util: Add missed fields in _attr__fprintf() and __attr_swap()
> >   tools headers: Sync x86 headers with kernel sources
> >   perf headers: Sync perf_event.h/perf_regs.h with the kernel headers
> >   perf regs: Support x86 eGPRs/SSP sampling
> >   perf regs: Support x86 SIMD registers sampling
> >   perf regs: Enable dumping of SIMD registers
> >   perf dwarf-regs: Add SIMD/eGPRs support for x86 DWARF registers
> >   perf tests: Add x86 eGPRs/SSP registers sampling test
> >   perf tests: Add SIMD registers sampling test
> >
> >  tools/arch/x86/include/asm/msr-index.h        |   7 +
> >  tools/arch/x86/include/uapi/asm/perf_regs.h   |  53 +++
> >  tools/include/uapi/linux/perf_event.h         |  49 +-
> >  tools/perf/Documentation/perf-record.txt      |  10 +-
> >  tools/perf/builtin-script.c                   |  93 +++-
> >  tools/perf/tests/shell/record.sh              | 257 +++++++++++
> >  .../util/dwarf-regs-arch/dwarf-regs-csky.c    |   2 +-
> >  .../util/dwarf-regs-arch/dwarf-regs-powerpc.c |   2 +-
> >  .../util/dwarf-regs-arch/dwarf-regs-s390.c    |   2 +-
> >  .../util/dwarf-regs-arch/dwarf-regs-x86.c     | 140 +++++-
> >  tools/perf/util/dwarf-regs.c                  |   9 +-
> >  tools/perf/util/evsel.c                       | 106 ++++-
> >  tools/perf/util/evsel.h                       |   7 +
> >  tools/perf/util/header.c                      |   3 +-
> >  tools/perf/util/include/dwarf-regs.h          |   7 +-
> >  tools/perf/util/parse-regs-options.c          | 210 ++++++++-
> >  .../perf/util/perf-regs-arch/perf_regs_x86.c  | 436 +++++++++++++++++-
> >  tools/perf/util/perf_event_attr_fprintf.c     |  13 +
> >  tools/perf/util/perf_regs.c                   |  84 +++-
> >  tools/perf/util/perf_regs.h                   |  21 +-
> >  tools/perf/util/record.h                      |   7 +
> >  tools/perf/util/sample.h                      |   5 +
> >  .../scripting-engines/trace-event-python.c    | 127 ++++-
> >  tools/perf/util/session.c                     | 112 ++++-
> >  tools/perf/util/synthetic-events.c            |  38 ++
> >  tools/perf/util/unwind-libdw.c                |   6 +-
> >  26 files changed, 1696 insertions(+), 110 deletions(-)
> >
> >
> > base-commit: e01c7bd5b1eece254bcbf282db066b12c4815d21