Allow users to specify trace event fields to use in aggregated sums via a new 'vals=' keyword. Before this addition, the only aggregated sum supported was the implied value 'hitcount'. With this addition, 'hitcount' is also supported as an explicit value field, as is any numeric trace event field.
This expands the hist trigger syntax from this: # echo hist:keys=xxx [ if filter] > event/trigger to this: # echo hist:keys=xxx:vals=yyy [ if filter] > event/trigger Signed-off-by: Tom Zanussi <[email protected]> Tested-by: Masami Hiramatsu <[email protected]> --- kernel/trace/trace.c | 12 ++++--- kernel/trace/trace_events_hist.c | 75 +++++++++++++++++++++++++++++++++++++++- 2 files changed, 81 insertions(+), 6 deletions(-) diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 078db8f..0310500 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -3825,14 +3825,16 @@ static const char readme_msg[] = #ifdef CONFIG_HIST_TRIGGERS " hist trigger\t- If set, event hits are aggregated into a hash table\n" "\t Format: hist:keys=<field1>\n" + "\t [:values=<field1[,field2,...]>]\n" "\t [:size=#entries]\n" "\t [if <filter>]\n\n" "\t When a matching event is hit, an entry is added to a hash\n" - "\t table using the key named, and the value of a sum called\n" - "\t 'hitcount' is incremented. Keys correspond to fields in the\n" - "\t event's format description. Keys can be any field. The\n" - "\t 'size' parameter can be used to specify more or fewer than\n" - "\t the default 2048 entries for the hashtable size.\n\n" + "\t table using the key(s) and value(s) named, and the value of a\n" + "\t sum called 'hitcount' is incremented. Keys and values\n" + "\t correspond to fields in the event's format description. Keys\n" + "\t can be any field. Values must correspond to numeric fields.\n" + "\t The 'size' parameter can be used to specify more or fewer\n" + "\t than the default 2048 entries 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." #endif diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c index 3c86ab2..389ffa0 100644 --- a/kernel/trace/trace_events_hist.c +++ b/kernel/trace/trace_events_hist.c @@ -84,6 +84,7 @@ enum hist_field_flags { struct hist_trigger_attrs { char *keys_str; + char *vals_str; unsigned int map_bits; }; @@ -165,6 +166,7 @@ static void destroy_hist_trigger_attrs(struct hist_trigger_attrs *attrs) return; kfree(attrs->keys_str); + kfree(attrs->vals_str); kfree(attrs); } @@ -183,6 +185,10 @@ static struct hist_trigger_attrs *parse_hist_trigger_attrs(char *trigger_str) if (!strncmp(str, "keys", strlen("keys")) || !strncmp(str, "key", strlen("key"))) attrs->keys_str = kstrdup(str, GFP_KERNEL); + else if (!strncmp(str, "values", strlen("values")) || + !strncmp(str, "vals", strlen("vals")) || + !strncmp(str, "val", strlen("val"))) + attrs->vals_str = kstrdup(str, GFP_KERNEL); else if (!strncmp(str, "size", strlen("size"))) { int map_bits = parse_map_size(str); @@ -271,13 +277,66 @@ static int create_hitcount_val(struct hist_trigger_data *hist_data) return 0; } +static int create_val_field(struct hist_trigger_data *hist_data, + unsigned int val_idx, + struct trace_event_file *file, + char *field_str) +{ + struct ftrace_event_field *field = NULL; + unsigned long flags = 0; + int ret = 0; + + field = trace_find_event_field(file->event_call, field_str); + if (!field) { + ret = -EINVAL; + goto out; + } + + hist_data->fields[val_idx] = create_hist_field(field, flags); + if (!hist_data->fields[val_idx]) { + ret = -ENOMEM; + goto out; + } + hist_data->n_vals++; + out: + return ret; +} + static int create_val_fields(struct hist_trigger_data *hist_data, struct trace_event_file *file) { + unsigned int vals_max = TRACING_MAP_FIELDS_MAX - TRACING_MAP_KEYS_MAX; + char *fields_str, *field_str; + unsigned int i, j; int ret; ret = create_hitcount_val(hist_data); + if (ret) + goto out; + fields_str = hist_data->attrs->vals_str; + if (!fields_str) + goto out; + + strsep(&fields_str, "="); + if (!fields_str) + goto out; + + vals_max = TRACING_MAP_FIELDS_MAX - TRACING_MAP_KEYS_MAX; + + for (i = 0, j = 1; i < vals_max; i++) { + field_str = strsep(&fields_str, ","); + if (!field_str) + break; + if (!strcmp(field_str, "hitcount")) + continue; + ret = create_val_field(hist_data, j++, file, field_str); + if (ret) + goto out; + } + if (fields_str) + ret = -EINVAL; + out: return ret; } @@ -542,6 +601,12 @@ hist_trigger_entry_print(struct seq_file *m, seq_printf(m, " hitcount: %10llu", 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)); + } + seq_puts(m, "\n"); } @@ -649,7 +714,15 @@ static int event_hist_trigger_print(struct seq_file *m, } seq_puts(m, ":vals="); - seq_puts(m, "hitcount"); + + for_each_hist_val_field(i, hist_data) { + if (i == HITCOUNT_IDX) + seq_puts(m, "hitcount"); + else { + seq_puts(m, ","); + hist_field_print(m, hist_data->fields[i]); + } + } seq_puts(m, ":sort="); seq_puts(m, "hitcount"); -- 1.9.3 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
