diff options
| author | Mark Brown <broonie@kernel.org> | 2026-05-29 18:09:26 +0100 |
|---|---|---|
| committer | Mark Brown <broonie@kernel.org> | 2026-05-29 18:09:26 +0100 |
| commit | 6a2f8c339e219a7e4d9939f54c9bba8625c5fa58 (patch) | |
| tree | d29b606f59ebc13fc04067affa99833d0c3cb0ab /Documentation | |
| parent | 25d928ed202826ffe8ee0f7944b80be922c5d081 (diff) | |
| parent | 6f2bf64ba8ad6f8ea4f2b2207952814d9f3edcc2 (diff) | |
| download | linux-next-history-6a2f8c339e219a7e4d9939f54c9bba8625c5fa58.tar.gz | |
Merge branch 'for-next' of https://git.kernel.org/pub/scm/linux/kernel/git/s390/linux.git
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/arch/s390/s390dbf.rst | 30 | ||||
| -rw-r--r-- | Documentation/trace/ftrace.rst | 4 |
2 files changed, 34 insertions, 0 deletions
diff --git a/Documentation/arch/s390/s390dbf.rst b/Documentation/arch/s390/s390dbf.rst index aad6d88974fe5..034374c88dbaf 100644 --- a/Documentation/arch/s390/s390dbf.rst +++ b/Documentation/arch/s390/s390dbf.rst @@ -106,6 +106,36 @@ the ``debug_stoppable`` sysctl. If you set ``debug_stoppable`` to 0 the debug feature cannot be stopped. If the debug feature is already stopped, it will stay deactivated. +Kernel parameters +----------------- +The size and log levels of debug logs can be configured early during boot using +the ``s390dbf`` kernel parameter. The parameter accepts a debug log name, a log +level, and a log size, separated by colon characters (``:``). To configure only +a single attribute, either the log level or the log size may be omitted. + +To configure multiple debug logs, the parameter may be specified multiple times, +or multiple parameter sets may be provided in a single instance, separated by +commas. + +Parameter format:: + + s390dbf=<name|pattern>:[<level>|-]:[<pages>][,...] + +where: + +- ``name`` specifies either an exact debug log name or a shell-style wildcard + pattern +- ``level`` specifies the log level, or ``-`` to completely deactivate the log +- ``pages`` specifies the debug area size in pages + +Example:: + + s390dbf=cio*:6:128,sclp_err::2 + +This example sets the log level to 6 and the log size to 128 pages for all debug +logs whose names start with ``cio``. It also sets the log level of the +``sclp_err`` debug log to 2. + Kernel Interfaces: ------------------ diff --git a/Documentation/trace/ftrace.rst b/Documentation/trace/ftrace.rst index b9efb148a5c22..f4d3f4d35ed5b 100644 --- a/Documentation/trace/ftrace.rst +++ b/Documentation/trace/ftrace.rst @@ -570,6 +570,10 @@ of ftrace. Here is a list of some of the key files: to correlate events across hypervisor/guest if tb_offset is known. + s390-tod: + This uses the s390 TOD clock value. This clock is usually in + sync across virtual machines and STP-enabled machines. + mono: This uses the fast monotonic clock (CLOCK_MONOTONIC) which is monotonic and is subject to NTP rate adjustments. |