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Diffstat (limited to 'Documentation/admin-guide/kernel-parameters.txt')
| -rw-r--r-- | Documentation/admin-guide/kernel-parameters.txt | 17 |
1 files changed, 17 insertions, 0 deletions
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index 388653448e72..3803f2b7f065 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -6743,6 +6743,15 @@ the same thing would happen if it was left off). The irq_handler_entry event, and all events under the "initcall" system. + Flags can be added to the instance to modify its behavior when it is + created. The flags are separated by '^'. Currently there's only one flag + defined, and that's "traceoff", to have the tracing instance tracing + disabled after it is created. + + trace_instance=foo^traceoff,sched,irq + + The flags must come before the defined events. + If memory has been reserved (see memmap for x86), the instance can use that memory: @@ -6765,6 +6774,14 @@ kernel versions where the validator will fail and reset the ring buffer if the layout is not the same as the previous kernel. + If the ring buffer is used for persistent bootups and has events enabled, + it is recommend to disable tracing so that events from a previous boot do not + mix with events of the current boot (unless you are debugging a random crash + at boot up). + + reserve_mem=12M:4096:trace trace_instance=boot_map^traceoff@trace,sched,irq + + trace_options=[option-list] [FTRACE] Enable or disable tracer options at boot. The option-list is a comma delimited list of options |