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