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tailspin(1)               BSD General Commands Manual              tailspin(1)


NAME

     tailspin -- configure, save and print tailspin output


SYNOPSIS

     tailspin info
     tailspin enable
     tailspin disable
     tailspin set buffer-size buffer-size-mb
                 ktrace-filter-descriptor filter-desc
                 oncore-sampling-period period-in-ns
                 full-system-sampling-period period-in-ns
     tailspin reset
     tailspin save [-r reason-string] [-l num-seconds] [-n] [path-to-file]
     tailspin symbolicate path-to-file
     tailspin stat [-v] path-to-file


DESCRIPTION

     tailspin configures the system to continuously sample callstacks of pro-
     cesses and select kdebug events in the kernel trace buffer. When tailspin
     data is recorded to a file, the tailspin file will contain information
     about the system state from about 20s prior to the save. The tailspind
     daemon is a helper daemon for the tailspin feature and should not be run
     manually.


SUBCOMMANDS

     tailspin uses a subcommand syntax to separate different functionality
     into logical groups.  Each subcommand takes its own set of options.

     info       Print information about the current configuration of tailspin.

     enable     Enable tailspin collection. Enablement persists across reboots
                and upgrade installs.

     disable    Stop tailspin collection. Disablement persists across reboots
                and upgrade installs. tailspin can be enabled again after it
                has been disabled, using the same configuration.

     set        Configure the 4 tunable parameters of tailspin. Any change
                applied will persist across reboots and upgrade installs.

                buffer-size buffer-size-mb
                        Set up the kernel trace buffer to be buffer-size-mb
                        big.

                ktrace-filter-descriptor filter-desc
                        Apply the filter-desc to the tailspin configuration,
                        thereby controlling which events are traced by tail-
                        spin.  See FILTER DESCRIPTIONS on the syntax of a fil-
                        ter.

                oncore-sampling-period period-in-ns
                        Set up a timer in the tailspin configuration to sample
                        the threads that are on the CPU when the timer fires
                        every period-in-ns.  The minimum period allowed is 1
                        ms.

                full-system-sampling-period period-in-ns
                        Set up a timer in the tailspin configuration to sample
                        all threads of all processes when the timer fires
                        every period-in-ns.  The minimum period allowed is 10
                        ms.

     reset      Remove all custom configuration of tailspin and reset to sys-
                tem default.

     save [-r reason-string] [-l num-seconds] [-n] [path-to-file]

                Save the current contents of the kernel trace buffer contain-
                ing tailspin data to path-to-file.

                -r reason-string
                        Include a key in the tailspin file indicating why it
                        was saved. This reason can be viewed with tailspin
                        stat.

                -l num-seconds
                        Limit the data in tailspin file to that of the last
                        num-seconds.

                -n      Save tailspin file without symbolicating.

     symbolicate path-to-file
                Symbolicate the tailspin report at path-to-file.

     stat [-v] path-to-file
                Print aggregate information about the data in the tailspin
                file.

                -v      Print layout information of tailspin file.


FILTER DESCRIPTIONS

     A filter description is a comma-separated list of class and subclass
     specifiers that indicate which events should be traced.   A class speci-
     fier starts with `C' followed by a number between 0 and 255 inclusive,
     specified in either decimal or hex (when prepended with "0x"). A subclass
     specifier starts with `S' and takes two bytes.  The high byte is the
     class and the low byte is the subclass of that class.

     For example, this filter description would enable classes 0x1 and 0x25
     and the subclasses 0x21 and 0x23 of class 0x5:
     `C1,C0x25,S0x0521,S0x0523'.  The `ALL' filter description enables events
     from all classes.


VIEWING TAILSPIN DATA

     tailspin data can be viewed by ktrace(1), spindump(8) and fs_usage(1).


DIAGNOSTICS

     The tailspin utility exits 0 on success, and >0 if an error occurs.


SEE ALSO

     ktrace(1), fs_usage(1), spindump(8)

Darwin                           22 June 2016                           Darwin

Mac OS X 10.12.6 - Generated Sun Oct 29 09:54:09 CDT 2017
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