From: Steven Rostedt Date: Fri, 16 Jan 2009 00:12:40 +0000 (-0500) Subject: ftrace: add stack trace to function tracer X-Git-Tag: v2.6.30-rc1~2^2~166 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=5361499101306cfb776c3cfa0f69d0479bc63868;p=pandora-kernel.git ftrace: add stack trace to function tracer Impact: new feature to stack trace any function Chris Mason asked about being able to pick and choose a function and get a stack trace from it. This feature enables his request. # echo io_schedule > /debug/tracing/set_ftrace_filter # echo function > /debug/tracing/current_tracer # echo func_stack_trace > /debug/tracing/trace_options Produces the following in /debug/tracing/trace: kjournald-702 [001] 135.673060: io_schedule <-sync_buffer kjournald-702 [002] 135.673671: <= sync_buffer <= __wait_on_bit <= out_of_line_wait_on_bit <= __wait_on_buffer <= sync_dirty_buffer <= journal_commit_transaction <= kjournald Note, be careful about turning this on without filtering the functions. You may find that you have a 10 second lag between typing and seeing what you typed. This is why the stack trace for the function tracer does not use the same stack_trace flag as the other tracers use. Signed-off-by: Steven Rostedt Signed-off-by: Ingo Molnar --- Reading git-diff-tree failed