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author | Robert Elliott <elliott@hp.com> | 2014-05-20 17:10:51 -0500 |
---|---|---|
committer | Steven Rostedt <rostedt@goodmis.org> | 2014-05-20 23:29:32 -0400 |
commit | 607e3a29203633eaec7334f2f58f9653df788a06 (patch) | |
tree | f4fc79986cbd5cb935141e47a982f014c1aeadcc | |
parent | ccdb594653b1c0d5b0f3e6f8bf764c544ba0606d (diff) | |
download | op-kernel-dev-607e3a29203633eaec7334f2f58f9653df788a06.zip op-kernel-dev-607e3a29203633eaec7334f2f58f9653df788a06.tar.gz |
tracing: Add funcgraph_tail option to print function name after closing braces
In the function-graph tracer, add a funcgraph_tail option
to print the function name on all } lines, not just
functions whose first line is no longer in the trace
buffer.
If a function calls other traced functions, its total
time appears on its } line. This change allows grep
to be used to determine the function for which the
line corresponds.
Update Documentation/trace/ftrace.txt to describe
this new option.
Link: http://lkml.kernel.org/p/20140520221041.8359.6782.stgit@beardog.cce.hp.com
Signed-off-by: Robert Elliott <elliott@hp.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
-rw-r--r-- | Documentation/trace/ftrace.txt | 26 | ||||
-rw-r--r-- | kernel/trace/trace.h | 1 | ||||
-rw-r--r-- | kernel/trace/trace_functions_graph.c | 9 |
3 files changed, 33 insertions, 3 deletions
diff --git a/Documentation/trace/ftrace.txt b/Documentation/trace/ftrace.txt index bd36598..2479b2a 100644 --- a/Documentation/trace/ftrace.txt +++ b/Documentation/trace/ftrace.txt @@ -2003,6 +2003,32 @@ want, depending on your needs. 360.774530 | 1) 0.594 us | __phys_addr(); +The function name is always displayed after the closing bracket +for a function if the start of that function is not in the +trace buffer. + +Display of the function name after the closing bracket may be +enabled for functions whose start is in the trace buffer, +allowing easier searching with grep for function durations. +It is default disabled. + + hide: echo nofuncgraph-tail > trace_options + show: echo funcgraph-tail > trace_options + + Example with nofuncgraph-tail (default): + 0) | putname() { + 0) | kmem_cache_free() { + 0) 0.518 us | __phys_addr(); + 0) 1.757 us | } + 0) 2.861 us | } + + Example with funcgraph-tail: + 0) | putname() { + 0) | kmem_cache_free() { + 0) 0.518 us | __phys_addr(); + 0) 1.757 us | } /* kmem_cache_free() */ + 0) 2.861 us | } /* putname() */ + You can put some comments on specific functions by using trace_printk() For example, if you want to put a comment inside the __might_sleep() function, you just have to include diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index 6805063..217207a 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -725,6 +725,7 @@ extern unsigned long trace_flags; #define TRACE_GRAPH_PRINT_DURATION 0x10 #define TRACE_GRAPH_PRINT_ABS_TIME 0x20 #define TRACE_GRAPH_PRINT_IRQS 0x40 +#define TRACE_GRAPH_PRINT_TAIL 0x80 #define TRACE_GRAPH_PRINT_FILL_SHIFT 28 #define TRACE_GRAPH_PRINT_FILL_MASK (0x3 << TRACE_GRAPH_PRINT_FILL_SHIFT) diff --git a/kernel/trace/trace_functions_graph.c b/kernel/trace/trace_functions_graph.c index af08dd5..4de3e57 100644 --- a/kernel/trace/trace_functions_graph.c +++ b/kernel/trace/trace_functions_graph.c @@ -55,11 +55,13 @@ static struct tracer_opt trace_opts[] = { { TRACER_OPT(funcgraph-abstime, TRACE_GRAPH_PRINT_ABS_TIME) }, /* Display interrupts */ { TRACER_OPT(funcgraph-irqs, TRACE_GRAPH_PRINT_IRQS) }, + /* Display function name after trailing } */ + { TRACER_OPT(funcgraph-tail, TRACE_GRAPH_PRINT_TAIL) }, { } /* Empty entry */ }; static struct tracer_flags tracer_flags = { - /* Don't display overruns and proc by default */ + /* Don't display overruns, proc, or tail by default */ .val = TRACE_GRAPH_PRINT_CPU | TRACE_GRAPH_PRINT_OVERHEAD | TRACE_GRAPH_PRINT_DURATION | TRACE_GRAPH_PRINT_IRQS, .opts = trace_opts @@ -1167,9 +1169,10 @@ print_graph_return(struct ftrace_graph_ret *trace, struct trace_seq *s, * If the return function does not have a matching entry, * then the entry was lost. Instead of just printing * the '}' and letting the user guess what function this - * belongs to, write out the function name. + * belongs to, write out the function name. Always do + * that if the funcgraph-tail option is enabled. */ - if (func_match) { + if (func_match && !(flags & TRACE_GRAPH_PRINT_TAIL)) { ret = trace_seq_puts(s, "}\n"); if (!ret) return TRACE_TYPE_PARTIAL_LINE; |