From: "Steven Rostedt (Red Hat)" <rost...@goodmis.org> Coming in v3.16, trace events will be able to save bitmasks in raw format in the ring buffer and output it with the __get_bitmask() macro.
In order for userspace tools to parse this, it must be able to handle the __get_bitmask() call and be able to convert the data that's in the ring buffer into a nice bitmask format. The output is similar to what the kernel uses to print bitmasks, with a comma separator every 4 bytes (8 characters). This allows for cpumasks to also be saved efficiently. The first user is the thermal:thermal_power_limit event which has the following output: thermal_power_limit: cpus=0000000f freq=1900000 cdev_state=0 power=5252 Link: http://lkml.kernel.org/r/20140506132238.22e13...@gandalf.local.home Suggested-by: Javi Merino <javi.mer...@arm.com> Signed-off-by: Steven Rostedt <rost...@goodmis.org> Acked-by: Namhyung Kim <namhy...@kernel.org> Tested-by: Javi Merino <javi.mer...@arm.com> Link: http://lkml.kernel.org/r/20140603032224.229186...@goodmis.org Signed-off-by: Jiri Olsa <jo...@kernel.org> --- tools/lib/traceevent/event-parse.c | 113 +++++++++++++++++++++ tools/lib/traceevent/event-parse.h | 7 ++ .../perf/util/scripting-engines/trace-event-perl.c | 1 + .../util/scripting-engines/trace-event-python.c | 1 + 4 files changed, 122 insertions(+) diff --git a/tools/lib/traceevent/event-parse.c b/tools/lib/traceevent/event-parse.c index b83184f..93825a1 100644 --- a/tools/lib/traceevent/event-parse.c +++ b/tools/lib/traceevent/event-parse.c @@ -765,6 +765,9 @@ static void free_arg(struct print_arg *arg) case PRINT_BSTRING: free(arg->string.string); break; + case PRINT_BITMASK: + free(arg->bitmask.bitmask); + break; case PRINT_DYNAMIC_ARRAY: free(arg->dynarray.index); break; @@ -2268,6 +2271,7 @@ static int arg_num_eval(struct print_arg *arg, long long *val) case PRINT_FIELD ... PRINT_SYMBOL: case PRINT_STRING: case PRINT_BSTRING: + case PRINT_BITMASK: default: do_warning("invalid eval type %d", arg->type); ret = 0; @@ -2296,6 +2300,7 @@ static char *arg_eval (struct print_arg *arg) case PRINT_FIELD ... PRINT_SYMBOL: case PRINT_STRING: case PRINT_BSTRING: + case PRINT_BITMASK: default: do_warning("invalid eval type %d", arg->type); break; @@ -2683,6 +2688,35 @@ process_str(struct event_format *event __maybe_unused, struct print_arg *arg, return EVENT_ERROR; } +static enum event_type +process_bitmask(struct event_format *event __maybe_unused, struct print_arg *arg, + char **tok) +{ + enum event_type type; + char *token; + + if (read_expect_type(EVENT_ITEM, &token) < 0) + goto out_free; + + arg->type = PRINT_BITMASK; + arg->bitmask.bitmask = token; + arg->bitmask.offset = -1; + + if (read_expected(EVENT_DELIM, ")") < 0) + goto out_err; + + type = read_token(&token); + *tok = token; + + return type; + + out_free: + free_token(token); + out_err: + *tok = NULL; + return EVENT_ERROR; +} + static struct pevent_function_handler * find_func_handler(struct pevent *pevent, char *func_name) { @@ -2797,6 +2831,10 @@ process_function(struct event_format *event, struct print_arg *arg, free_token(token); return process_str(event, arg, tok); } + if (strcmp(token, "__get_bitmask") == 0) { + free_token(token); + return process_bitmask(event, arg, tok); + } if (strcmp(token, "__get_dynamic_array") == 0) { free_token(token); return process_dynamic_array(event, arg, tok); @@ -3324,6 +3362,7 @@ eval_num_arg(void *data, int size, struct event_format *event, struct print_arg return eval_type(val, arg, 0); case PRINT_STRING: case PRINT_BSTRING: + case PRINT_BITMASK: return 0; case PRINT_FUNC: { struct trace_seq s; @@ -3556,6 +3595,60 @@ static void print_str_to_seq(struct trace_seq *s, const char *format, trace_seq_printf(s, format, str); } +static void print_bitmask_to_seq(struct pevent *pevent, + struct trace_seq *s, const char *format, + int len_arg, const void *data, int size) +{ + int nr_bits = size * 8; + int str_size = (nr_bits + 3) / 4; + int len = 0; + char buf[3]; + char *str; + int index; + int i; + + /* + * The kernel likes to put in commas every 32 bits, we + * can do the same. + */ + str_size += (nr_bits - 1) / 32; + + str = malloc(str_size + 1); + if (!str) { + do_warning("%s: not enough memory!", __func__); + return; + } + str[str_size] = 0; + + /* Start out with -2 for the two chars per byte */ + for (i = str_size - 2; i >= 0; i -= 2) { + /* + * data points to a bit mask of size bytes. + * In the kernel, this is an array of long words, thus + * endianess is very important. + */ + if (pevent->file_bigendian) + index = size - (len + 1); + else + index = len; + + snprintf(buf, 3, "%02x", *((unsigned char *)data + index)); + memcpy(str + i, buf, 2); + len++; + if (!(len & 3) && i > 0) { + i--; + str[i] = ','; + } + } + + if (len_arg >= 0) + trace_seq_printf(s, format, len_arg, str); + else + trace_seq_printf(s, format, str); + + free(str); +} + static void print_str_arg(struct trace_seq *s, void *data, int size, struct event_format *event, const char *format, int len_arg, struct print_arg *arg) @@ -3691,6 +3784,23 @@ static void print_str_arg(struct trace_seq *s, void *data, int size, case PRINT_BSTRING: print_str_to_seq(s, format, len_arg, arg->string.string); break; + case PRINT_BITMASK: { + int bitmask_offset; + int bitmask_size; + + if (arg->bitmask.offset == -1) { + struct format_field *f; + + f = pevent_find_any_field(event, arg->bitmask.bitmask); + arg->bitmask.offset = f->offset; + } + bitmask_offset = data2host4(pevent, data + arg->bitmask.offset); + bitmask_size = bitmask_offset >> 16; + bitmask_offset &= 0xffff; + print_bitmask_to_seq(pevent, s, format, len_arg, + data + bitmask_offset, bitmask_size); + break; + } case PRINT_OP: /* * The only op for string should be ? : @@ -4822,6 +4932,9 @@ static void print_args(struct print_arg *args) case PRINT_BSTRING: printf("__get_str(%s)", args->string.string); break; + case PRINT_BITMASK: + printf("__get_bitmask(%s)", args->bitmask.bitmask); + break; case PRINT_TYPE: printf("(%s)", args->typecast.type); print_args(args->typecast.item); diff --git a/tools/lib/traceevent/event-parse.h b/tools/lib/traceevent/event-parse.h index 56e0e6c..7a3873f 100644 --- a/tools/lib/traceevent/event-parse.h +++ b/tools/lib/traceevent/event-parse.h @@ -208,6 +208,11 @@ struct print_arg_string { int offset; }; +struct print_arg_bitmask { + char *bitmask; + int offset; +}; + struct print_arg_field { char *name; struct format_field *field; @@ -274,6 +279,7 @@ enum print_arg_type { PRINT_DYNAMIC_ARRAY, PRINT_OP, PRINT_FUNC, + PRINT_BITMASK, }; struct print_arg { @@ -288,6 +294,7 @@ struct print_arg { struct print_arg_hex hex; struct print_arg_func func; struct print_arg_string string; + struct print_arg_bitmask bitmask; struct print_arg_op op; struct print_arg_dynarray dynarray; }; diff --git a/tools/perf/util/scripting-engines/trace-event-perl.c b/tools/perf/util/scripting-engines/trace-event-perl.c index e108207..af7da56 100644 --- a/tools/perf/util/scripting-engines/trace-event-perl.c +++ b/tools/perf/util/scripting-engines/trace-event-perl.c @@ -215,6 +215,7 @@ static void define_event_symbols(struct event_format *event, case PRINT_BSTRING: case PRINT_DYNAMIC_ARRAY: case PRINT_STRING: + case PRINT_BITMASK: break; case PRINT_TYPE: define_event_symbols(event, ev_name, args->typecast.item); diff --git a/tools/perf/util/scripting-engines/trace-event-python.c b/tools/perf/util/scripting-engines/trace-event-python.c index cd9774d..c3de097 100644 --- a/tools/perf/util/scripting-engines/trace-event-python.c +++ b/tools/perf/util/scripting-engines/trace-event-python.c @@ -197,6 +197,7 @@ static void define_event_symbols(struct event_format *event, case PRINT_BSTRING: case PRINT_DYNAMIC_ARRAY: case PRINT_FUNC: + case PRINT_BITMASK: /* we should warn... */ return; } -- 1.8.3.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
