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Commit 48078d2d authored by Liam R. Howlett's avatar Liam R. Howlett Committed by David S. Miller
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sparc/ftrace: Fix ftrace graph time measurement



The ftrace function_graph time measurements of a given function is not
accurate according to those recorded by ftrace using the function
filters.  This change pulls the x86_64 fix from 'commit 722b3c74
("ftrace/graph: Trace function entry before updating index")' into the
sparc specific prepare_ftrace_return which stops ftrace from
counting interrupted tasks in the time measurement.

Example measurements for select_task_rq_fair running "hackbench 100
process 1000":

              |  tracing/trace_stat/function0  |  function_graph
 Before patch |  2.802 us                      |  4.255 us
 After patch  |  2.749 us                      |  3.094 us

Signed-off-by: default avatarLiam R. Howlett <Liam.Howlett@Oracle.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent deba804c
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