This is based on top of the deferred unwind core patch series:

  https://lore.kernel.org/linux-trace-kernel/20250611005421.144238328@goodmis.org/

Which is based on top of v6.16-rc1.

This series implements the perf interface to use deferred user space stack
tracing. This version fixes a few issues from v9 and addresses the comments
from v8 where as v9 was just a rebase.

Changes since v9: https://lore.kernel.org/linux-trace-kernel/20250611013421.040264741@goodmis.org/

- Remove CONFIG_HAVE_PERF_CALLCHAIN_DEFERRED as it is never used.

- Fixed up the synchronization of rcuwait for cpu deferred events.

- Added more comments to describe how the unwind deferred works.

- Tagged the cpu_events with __rcu and added rcu annotation.
 

Josh Poimboeuf (5):
      perf: Remove get_perf_callchain() init_nr argument
      perf: Have get_perf_callchain() return NULL if crosstask and user are set
      perf: Simplify get_perf_callchain() user logic
      perf: Skip user unwind if the task is a kernel thread
      perf: Support deferred user callchains

Namhyung Kim (4):
      perf tools: Minimal CALLCHAIN_DEFERRED support
      perf record: Enable defer_callchain for user callchains
      perf script: Display PERF_RECORD_CALLCHAIN_DEFERRED
      perf tools: Merge deferred user callchains

Steven Rostedt (2):
      perf: Use current->flags & PF_KTHREAD instead of current->mm == NULL
      perf: Support deferred user callchains for per CPU events

----
 include/linux/perf_event.h                |  14 +-
 include/uapi/linux/perf_event.h           |  19 +-
 kernel/bpf/stackmap.c                     |   8 +-
 kernel/events/callchain.c                 |  49 ++--
 kernel/events/core.c                      | 420 +++++++++++++++++++++++++++++-
 tools/include/uapi/linux/perf_event.h     |  19 +-
 tools/lib/perf/include/perf/event.h       |   7 +
 tools/perf/Documentation/perf-script.txt  |   5 +
 tools/perf/builtin-script.c               |  92 +++++++
 tools/perf/util/callchain.c               |  24 ++
 tools/perf/util/callchain.h               |   3 +
 tools/perf/util/event.c                   |   1 +
 tools/perf/util/evlist.c                  |   1 +
 tools/perf/util/evlist.h                  |   1 +
 tools/perf/util/evsel.c                   |  39 +++
 tools/perf/util/evsel.h                   |   1 +
 tools/perf/util/machine.c                 |   1 +
 tools/perf/util/perf_event_attr_fprintf.c |   1 +
 tools/perf/util/sample.h                  |   3 +-
 tools/perf/util/session.c                 |  78 ++++++
 tools/perf/util/tool.c                    |   2 +
 tools/perf/util/tool.h                    |   4 +-
 22 files changed, 757 insertions(+), 35 deletions(-)