This series extends the recently introduced trace remotes
infrastructure, bringing useful features for developers:

  * dump_on_panic: Dump the trace remote buffer on system panic.
  * dmesg: Redirect remote events to dmesg.
  * trace_remote=: Configure a trace_remote from the commandline.
  * poll_ms: Modify the polling period.

It also brings a couple of optimisations:

  * In-header compressed length support for small events.
  * Single work thread for remote polling.

And some misc improvements:

  * Use kstrtobool where possible
  * Free resources on remote registration failure

v2:

Sashiko had a few spot-on comments on the v1 which forced me to heavily
re-arrange the series, so I thought it'd be alright to send a v2
already including those changes.

  * dump_on_oops -> dump_on_panic
  * printk -> dmesg
  * Allow to configure poll_ms
  * Make the ring_buffer_iter functions panic-friendly
  * Gate tracefs .open on remote registration (Sashiko)
  * Use irqsave for reader lock (Sashiko)
  * Fix iter locking for TRI_DMESG (Sashiko)
  * Yield in the dmesg work (Sashiko)

v1 (https://lore.kernel.org/all/20260602171146.2238998-1-vdonnefort@google.com/)

Vincent Donnefort (18):
  tracing/remotes: Gate tracefs files opening on trace remote
    registration
  tracing/remotes: Release tracefs,eventfs on registration failure
  tracing/remotes: Use kstrtobool for boolean tracefs files
  tracing/remotes: Use a single per-remote polling work
  tracing/simple_ring_buffer: Add support for compressed length
  tracing/remotes: Add dmesg tracefs file
  tracing/remotes: selftests: Add a test for the dmesg tracefs file
  tracing/remotes: selftests: Prefix hypervisor folder
  ring-buffer: Use irqsave for the reader lock in
    ring_buffer_poll_remote
  ring-buffer: Use panic-friendly locking in ring_buffer_iter interface
  ring-buffer: Add ring_buffer_read_remote_meta_page()
  ring-buffer: Add kerneldoc for ring_buffer_poll_remote
  tracing/remotes: Add dump_on_panic tracefs file
  tracing/remotes: selftests: Add a test for the dump_on_panic tracefs
    file
  tracing/remotes: Add poll_ms tracefs file
  tracing/remotes: Add trace_remote cmdline options
  Documentation: tracing/remotes: Add detailed tracefs layout
  Documentation/kernel-parameters: Add trace_remote

 .../admin-guide/kernel-parameters.txt         |  19 +
 Documentation/trace/remotes.rst               |  66 +-
 include/linux/ring_buffer.h                   |   1 +
 kernel/trace/ring_buffer.c                    |  86 +-
 kernel/trace/simple_ring_buffer.c             |  25 +-
 kernel/trace/trace_remote.c                   | 823 +++++++++++++++---
 .../buffer_size.tc                            |   0
 .../test.d/remotes/00hypervisor/dmesg.tc      |  11 +
 .../remotes/00hypervisor/dump_on_panic.tc     |  11 +
 .../{hypervisor => 00hypervisor}/hotplug.tc   |   0
 .../{hypervisor => 00hypervisor}/reset.tc     |   0
 .../{hypervisor => 00hypervisor}/trace.tc     |   0
 .../trace_pipe.tc                             |   0
 .../{hypervisor => 00hypervisor}/unloading.tc |   0
 .../selftests/ftrace/test.d/remotes/dmesg.tc  |  72 ++
 .../ftrace/test.d/remotes/dump_on_panic.tc    |  51 ++
 .../selftests/ftrace/test.d/remotes/functions |   2 +
 17 files changed, 1028 insertions(+), 139 deletions(-)
 rename tools/testing/selftests/ftrace/test.d/remotes/{hypervisor => 00hypervisor}/buffer_size.tc (100%)
 create mode 100644 tools/testing/selftests/ftrace/test.d/remotes/00hypervisor/dmesg.tc
 create mode 100644 tools/testing/selftests/ftrace/test.d/remotes/00hypervisor/dump_on_panic.tc
 rename tools/testing/selftests/ftrace/test.d/remotes/{hypervisor => 00hypervisor}/hotplug.tc (100%)
 rename tools/testing/selftests/ftrace/test.d/remotes/{hypervisor => 00hypervisor}/reset.tc (100%)
 rename tools/testing/selftests/ftrace/test.d/remotes/{hypervisor => 00hypervisor}/trace.tc (100%)
 rename tools/testing/selftests/ftrace/test.d/remotes/{hypervisor => 00hypervisor}/trace_pipe.tc (100%)
 rename tools/testing/selftests/ftrace/test.d/remotes/{hypervisor => 00hypervisor}/unloading.tc (100%)
 create mode 100644 tools/testing/selftests/ftrace/test.d/remotes/dmesg.tc
 create mode 100644 tools/testing/selftests/ftrace/test.d/remotes/dump_on_panic.tc


base-commit: e43ffb69e0438cddd72aaa30898b4dc446f664f8
-- 
2.54.0.1032.g2f8565e1d1-goog

Avoid interleaving run tests by prefixing the hypervisor folder.

Signed-off-by: Vincent Donnefort <vdonnefort@google.com>

diff --git a/tools/testing/selftests/ftrace/test.d/remotes/hypervisor/buffer_size.tc b/tools/testing/selftests/ftrace/test.d/remotes/00hypervisor/buffer_size.tc
similarity index 100%
rename from tools/testing/selftests/ftrace/test.d/remotes/hypervisor/buffer_size.tc
rename to tools/testing/selftests/ftrace/test.d/remotes/00hypervisor/buffer_size.tc
diff --git a/tools/testing/selftests/ftrace/test.d/remotes/hypervisor/dmesg.tc b/tools/testing/selftests/ftrace/test.d/remotes/00hypervisor/dmesg.tc
similarity index 100%
rename from tools/testing/selftests/ftrace/test.d/remotes/hypervisor/dmesg.tc
rename to tools/testing/selftests/ftrace/test.d/remotes/00hypervisor/dmesg.tc
diff --git a/tools/testing/selftests/ftrace/test.d/remotes/hypervisor/hotplug.tc b/tools/testing/selftests/ftrace/test.d/remotes/00hypervisor/hotplug.tc
similarity index 100%
rename from tools/testing/selftests/ftrace/test.d/remotes/hypervisor/hotplug.tc
rename to tools/testing/selftests/ftrace/test.d/remotes/00hypervisor/hotplug.tc
diff --git a/tools/testing/selftests/ftrace/test.d/remotes/hypervisor/reset.tc b/tools/testing/selftests/ftrace/test.d/remotes/00hypervisor/reset.tc
similarity index 100%
rename from tools/testing/selftests/ftrace/test.d/remotes/hypervisor/reset.tc
rename to tools/testing/selftests/ftrace/test.d/remotes/00hypervisor/reset.tc
diff --git a/tools/testing/selftests/ftrace/test.d/remotes/hypervisor/trace.tc b/tools/testing/selftests/ftrace/test.d/remotes/00hypervisor/trace.tc
similarity index 100%
rename from tools/testing/selftests/ftrace/test.d/remotes/hypervisor/trace.tc
rename to tools/testing/selftests/ftrace/test.d/remotes/00hypervisor/trace.tc
diff --git a/tools/testing/selftests/ftrace/test.d/remotes/hypervisor/trace_pipe.tc b/tools/testing/selftests/ftrace/test.d/remotes/00hypervisor/trace_pipe.tc
similarity index 100%
rename from tools/testing/selftests/ftrace/test.d/remotes/hypervisor/trace_pipe.tc
rename to tools/testing/selftests/ftrace/test.d/remotes/00hypervisor/trace_pipe.tc
diff --git a/tools/testing/selftests/ftrace/test.d/remotes/hypervisor/unloading.tc b/tools/testing/selftests/ftrace/test.d/remotes/00hypervisor/unloading.tc
similarity index 100%
rename from tools/testing/selftests/ftrace/test.d/remotes/hypervisor/unloading.tc
rename to tools/testing/selftests/ftrace/test.d/remotes/00hypervisor/unloading.tc
-- 
2.54.0.1032.g2f8565e1d1-goog