From 0c4a6b4666e8eb86dead3f09b40bb8ca4f614e4f Mon Sep 17 00:00:00 2001 From: Tom Zanussi Date: Thu, 3 Mar 2016 12:54:48 -0600 Subject: [PATCH] tracing: Add hist trigger 'hex' modifier for displaying numeric fields Allow users to have numeric fields displayed as hex values in the output by appending '.hex' to field names: # echo hist:keys=aaa,bbb.hex:vals=ccc.hex ... \ [ if filter] > event/trigger Link: http://lkml.kernel.org/r/67bd431edda2af5798d7694818f7e8d71b6b3463.1457029949.git.tom.zanussi@linux.intel.com Signed-off-by: Tom Zanussi Tested-by: Masami Hiramatsu Reviewed-by: Namhyung Kim Signed-off-by: Steven Rostedt --- kernel/trace/trace.c | 5 ++- kernel/trace/trace_events_hist.c | 62 ++++++++++++++++++++++++++++---- 2 files changed, 60 insertions(+), 7 deletions(-) diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 4097cd3763f7..2eb2eafbe7f5 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -3852,7 +3852,10 @@ static const char readme_msg[] = "\t used to specify more or fewer than the default 2048 entries\n" "\t for the hashtable size.\n\n" "\t Reading the 'hist' file for the event will dump the hash\n" - "\t table in its entirety to stdout.\n\n" + "\t table in its entirety to stdout. The default format used to\n" + "\t display a given field can be modified by appending any of the\n" + "\t following modifiers to the field name, as applicable:\n\n" + "\t .hex display a number as a hex value\n\n" "\t The 'pause' parameter can be used to pause an existing hist\n" "\t trigger or to start a hist trigger but not log any events\n" "\t until told to do so. 'continue' can be used to start or\n" diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c index 83cb25e067ad..8e49eeef8867 100644 --- a/kernel/trace/trace_events_hist.c +++ b/kernel/trace/trace_events_hist.c @@ -80,6 +80,7 @@ enum hist_field_flags { HIST_FIELD_FL_HITCOUNT = 1, HIST_FIELD_FL_KEY = 2, HIST_FIELD_FL_STRING = 4, + HIST_FIELD_FL_HEX = 8, }; struct hist_trigger_attrs { @@ -303,11 +304,23 @@ static int create_val_field(struct hist_trigger_data *hist_data, { struct ftrace_event_field *field = NULL; unsigned long flags = 0; + char *field_name; int ret = 0; if (WARN_ON(val_idx >= TRACING_MAP_VALS_MAX)) return -EINVAL; - field = trace_find_event_field(file->event_call, field_str); + + field_name = strsep(&field_str, "."); + if (field_str) { + if (strcmp(field_str, "hex") == 0) + flags |= HIST_FIELD_FL_HEX; + else { + ret = -EINVAL; + goto out; + } + } + + field = trace_find_event_field(file->event_call, field_name); if (!field) { ret = -EINVAL; goto out; @@ -372,6 +385,7 @@ static int create_key_field(struct hist_trigger_data *hist_data, struct ftrace_event_field *field = NULL; unsigned long flags = 0; unsigned int key_size; + char *field_name; int ret = 0; if (WARN_ON(key_idx >= TRACING_MAP_FIELDS_MAX)) @@ -379,7 +393,17 @@ static int create_key_field(struct hist_trigger_data *hist_data, flags |= HIST_FIELD_FL_KEY; - field = trace_find_event_field(file->event_call, field_str); + field_name = strsep(&field_str, "."); + if (field_str) { + if (strcmp(field_str, "hex") == 0) + flags |= HIST_FIELD_FL_HEX; + else { + ret = -EINVAL; + goto out; + } + } + + field = trace_find_event_field(file->event_call, field_name); if (!field) { ret = -EINVAL; goto out; @@ -713,7 +737,11 @@ hist_trigger_entry_print(struct seq_file *m, if (i > hist_data->n_vals) seq_puts(m, ", "); - if (key_field->flags & HIST_FIELD_FL_STRING) { + if (key_field->flags & HIST_FIELD_FL_HEX) { + uval = *(u64 *)(key + key_field->offset); + seq_printf(m, "%s: %llx", + key_field->field->name, uval); + } else if (key_field->flags & HIST_FIELD_FL_STRING) { seq_printf(m, "%s: %-50s", key_field->field->name, (char *)(key + key_field->offset)); } else { @@ -729,9 +757,15 @@ hist_trigger_entry_print(struct seq_file *m, tracing_map_read_sum(elt, HITCOUNT_IDX)); for (i = 1; i < hist_data->n_vals; i++) { - seq_printf(m, " %s: %10llu", - hist_data->fields[i]->field->name, - tracing_map_read_sum(elt, i)); + if (hist_data->fields[i]->flags & HIST_FIELD_FL_HEX) { + seq_printf(m, " %s: %10llx", + hist_data->fields[i]->field->name, + tracing_map_read_sum(elt, i)); + } else { + seq_printf(m, " %s: %10llu", + hist_data->fields[i]->field->name, + tracing_map_read_sum(elt, i)); + } } seq_puts(m, "\n"); @@ -816,9 +850,25 @@ const struct file_operations event_hist_fops = { .release = single_release, }; +static const char *get_hist_field_flags(struct hist_field *hist_field) +{ + const char *flags_str = NULL; + + if (hist_field->flags & HIST_FIELD_FL_HEX) + flags_str = "hex"; + + return flags_str; +} + static void hist_field_print(struct seq_file *m, struct hist_field *hist_field) { seq_printf(m, "%s", hist_field->field->name); + if (hist_field->flags) { + const char *flags_str = get_hist_field_flags(hist_field); + + if (flags_str) + seq_printf(m, ".%s", flags_str); + } } static int event_hist_trigger_print(struct seq_file *m,