On Tue, Aug 04, 2020 at 09:51:15AM -0300, Arnaldo Carvalho de Melo wrote: > Em Sat, Jul 18, 2020 at 02:48:09PM +0800, Changbin Du escreveu: > > The '-g/-G' options have already implied function_graph tracer should be > > used instead of function tracer. So the extra option '--tracer' can be > > killed. > > > > This patch changes the behavior as below: > > - By default, function tracer is used. > > - If '-g' or '-G' option is on, then function_graph tracer is used. > > - The perf configuration item 'ftrace.tracer' is marked as deprecated. > > - The option '--tracer' is marked as deprecated. > > You should try to be more granular, for instance, I think the decision > to change the default is questionable, but could be acceptable. > > But why deprecate the perf configuration for the default tracer? > > Say people who already use 'perf ftrace ls' go and use with this patch > and see that it changed the default from the function_graph tracer to > the function tracer and disagree with you, they want the default to be > the function graph tracer, know that there is (or there was) a > ftrace.tracer in ~/.prefconfig, and then try that, only to find out that > it is not possible, frustrating :-\ > > So can we please remove this deprecation of ftrace.tracer so that people > used to how it was can get that behaviour back? > Agreed. If no -F or -G is given, we can use the ftrace.tracer as default tracer. Let me update it. Thanks.
> I'll look at the other patches so as to provide comments on all of > them and to speed things up I may end up removing this deprecation of > ftrace.tracer and apply the rest, we can always revisit parts that I > remove. > > - Arnaldo > > > Here are some examples. > > > > This will start tracing all functions using function tracer: > > $ sudo perf ftrace > > > > This will trace all functions using function graph tracer: > > $ sudo perf ftrace -G '*' > > > > This will trace function vfs_read using function graph tracer: > > $ sudo perf ftrace -G vfs_read > > > > Signed-off-by: Changbin Du <changbin...@gmail.com> > > > > --- > > v3: remove default '*' for -G/-T. > > --- > > tools/perf/Documentation/perf-config.txt | 5 ----- > > tools/perf/Documentation/perf-ftrace.txt | 2 +- > > tools/perf/builtin-ftrace.c | 15 ++++++++++----- > > 3 files changed, 11 insertions(+), 11 deletions(-) > > > > diff --git a/tools/perf/Documentation/perf-config.txt > > b/tools/perf/Documentation/perf-config.txt > > index c7d3df5798e2..a25fee7de3b2 100644 > > --- a/tools/perf/Documentation/perf-config.txt > > +++ b/tools/perf/Documentation/perf-config.txt > > @@ -612,11 +612,6 @@ trace.*:: > > "libbeauty", the default, to use the same argument beautifiers > > used in the > > strace-like sys_enter+sys_exit lines. > > > > -ftrace.*:: > > - ftrace.tracer:: > > - Can be used to select the default tracer. Possible values are > > - 'function' and 'function_graph'. > > - > > llvm.*:: > > llvm.clang-path:: > > Path to clang. If omit, search it from $PATH. > > diff --git a/tools/perf/Documentation/perf-ftrace.txt > > b/tools/perf/Documentation/perf-ftrace.txt > > index b80c84307dc9..952e46669168 100644 > > --- a/tools/perf/Documentation/perf-ftrace.txt > > +++ b/tools/perf/Documentation/perf-ftrace.txt > > @@ -24,7 +24,7 @@ OPTIONS > > > > -t:: > > --tracer=:: > > - Tracer to use: function_graph or function. > > + Tracer to use: function_graph or function. This option is deprecated. > > > > -v:: > > --verbose=:: > > diff --git a/tools/perf/builtin-ftrace.c b/tools/perf/builtin-ftrace.c > > index 2bfc1b0db536..5f53da87040d 100644 > > --- a/tools/perf/builtin-ftrace.c > > +++ b/tools/perf/builtin-ftrace.c > > @@ -27,7 +27,6 @@ > > #include "util/cap.h" > > #include "util/config.h" > > > > -#define DEFAULT_TRACER "function_graph" > > > > struct perf_ftrace { > > struct evlist *evlist; > > @@ -419,6 +418,7 @@ static int perf_ftrace_config(const char *var, const > > char *value, void *cb) > > if (strcmp(var, "ftrace.tracer")) > > return -1; > > > > + pr_warning("Configuration ftrace.tracer is deprecated\n"); > > if (!strcmp(value, "function_graph") || > > !strcmp(value, "function")) { > > ftrace->tracer = value; > > @@ -459,7 +459,7 @@ int cmd_ftrace(int argc, const char **argv) > > { > > int ret; > > struct perf_ftrace ftrace = { > > - .tracer = DEFAULT_TRACER, > > + .tracer = "function", > > .target = { .uid = UINT_MAX, }, > > }; > > const char * const ftrace_usage[] = { > > @@ -469,7 +469,7 @@ int cmd_ftrace(int argc, const char **argv) > > }; > > const struct option ftrace_options[] = { > > OPT_STRING('t', "tracer", &ftrace.tracer, "tracer", > > - "tracer to use: function_graph(default) or function"), > > + "tracer to use: function or function_graph (This option is > > deprecated)"), > > OPT_STRING('p', "pid", &ftrace.target.pid, "pid", > > "trace on existing process id"), > > OPT_INCR('v', "verbose", &verbose, > > @@ -479,11 +479,13 @@ int cmd_ftrace(int argc, const char **argv) > > OPT_STRING('C', "cpu", &ftrace.target.cpu_list, "cpu", > > "list of cpus to monitor"), > > OPT_CALLBACK('T', "trace-funcs", &ftrace.filters, "func", > > - "trace given functions only", parse_filter_func), > > + "trace given functions using function tracer", > > + parse_filter_func), > > OPT_CALLBACK('N', "notrace-funcs", &ftrace.notrace, "func", > > "do not trace given functions", parse_filter_func), > > OPT_CALLBACK('G', "graph-funcs", &ftrace.graph_funcs, "func", > > - "Set graph filter on given functions", parse_filter_func), > > + "trace given functions using function_graph tracer", > > + parse_filter_func), > > OPT_CALLBACK('g', "nograph-funcs", &ftrace.nograph_funcs, "func", > > "Set nograph filter on given functions", > > parse_filter_func), > > OPT_INTEGER('D', "graph-depth", &ftrace.graph_depth, > > @@ -505,6 +507,9 @@ int cmd_ftrace(int argc, const char **argv) > > if (!argc && target__none(&ftrace.target)) > > ftrace.target.system_wide = true; > > > > + if (!list_empty(&ftrace.graph_funcs) || > > !list_empty(&ftrace.nograph_funcs)) > > + ftrace.tracer = "function_graph"; > > + > > ret = target__validate(&ftrace.target); > > if (ret) { > > char errbuf[512]; > > -- > > 2.25.1 > > > > -- > > - Arnaldo -- Cheers, Changbin Du