perf ftrace: Add option for function filtering
The -T/--trace-funcs and -N/--notrace-funcs options are to specify functions to enable/disable tracing dynamically. The -G/--graph-funcs and -g/--nograph-funcs options are to set filters for function graph tracer. For example, to trace fault handling functions only: $ sudo perf ftrace -T *fault hello 0) | __do_page_fault() { 0) | handle_mm_fault() { 0) 2.117 us | __handle_mm_fault(); 0) 3.627 us | } 0) 7.811 us | } 0) | __do_page_fault() { 0) | handle_mm_fault() { 0) 2.014 us | __handle_mm_fault(); 0) 2.424 us | } 0) 2.951 us | } ... To trace all functions executed in __do_page_fault: $ sudo perf ftrace -G __do_page_fault hello 2) | __do_page_fault() { 3) 0.060 us | down_read_trylock(); 3) | find_vma() { 3) 0.075 us | vmacache_find(); 3) 0.053 us | vmacache_update(); 3) 1.246 us | } 3) | handle_mm_fault() { 3) 0.063 us | __rcu_read_lock(); 3) 0.056 us | mem_cgroup_from_task(); 3) 0.057 us | __rcu_read_unlock(); 3) | __handle_mm_fault() { 3) | filemap_map_pages() { 3) 0.058 us | __rcu_read_lock(); 3) | alloc_set_pte() { ... But don't want to show details in handle_mm_fault: $ sudo perf ftrace -G __do_page_fault -g handle_mm_fault hello 3) | __do_page_fault() { 3) 0.049 us | down_read_trylock(); 3) | find_vma() { 3) 0.048 us | vmacache_find(); 3) 0.041 us | vmacache_update(); 3) 0.680 us | } 3) 0.036 us | up_read(); 3) 4.547 us | } /* __do_page_fault */ ... Signed-off-by: NNamhyung Kim <namhyung@kernel.org> Tested-by: NArnaldo Carvalho de Melo <acme@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: kernel-team@lge.com Link: http://lkml.kernel.org/r/20170618142302.25390-3-namhyung@kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
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