Bug 10994 - utrace-free task_finder
Summary: utrace-free task_finder
Status: RESOLVED FIXED
Alias: None
Product: systemtap
Classification: Unclassified
Component: runtime (show other bugs)
Version: unspecified
: P2 normal
Target Milestone: ---
Assignee: David Smith
URL:
Keywords:
Depends on: 13146
Blocks:
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Reported: 2009-11-20 19:52 UTC by Frank Ch. Eigler
Modified: 2011-12-01 16:20 UTC (History)
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Description Frank Ch. Eigler 2009-11-20 19:52:21 UTC 
With recent kernel tracepoints for mmap/process tracking, as used
by the perf tool, we may be able to use a non-utrace backend for
the task_finder.  That in turn could enable utrace-free user-space
<sdt.h> probing, using the kprobe or similar non-utrace backend.
Comment 1 David Smith 2011-12-01 16:20:08 UTC 
As of commit c0f710f991 (which merged the dsmith/task_finder2 branch into the master branch), there is a non-utrace backend for the task_finder for kernels without utrace.

A kernel must support specific tracepoints (CONFIG_TRACEPOINTS) for this to work:

- sched_process_fork
- sched_process_exit
- sys_enter
- sys_exit

and one of the following:

- the not quite upstream 'sched_process_exec' tracepoint; or
- the ftrace_set_filter() function (which depends on CONFIG_FTRACE)