Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752423AbdFZWvc (ORCPT ); Mon, 26 Jun 2017 18:51:32 -0400 Received: from mga02.intel.com ([134.134.136.20]:25283 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752136AbdFZWut (ORCPT ); Mon, 26 Jun 2017 18:50:49 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.39,397,1493708400"; d="scan'208";a="985471952" From: Tom Zanussi To: rostedt@goodmis.org Cc: tglx@linutronix.de, mhiramat@kernel.org, namhyung@kernel.org, vedang.patel@intel.com, linux-kernel@vger.kernel.org, linux-rt-users@vger.kernel.org, Tom Zanussi Subject: [PATCH 28/32] tracing: Add hist trigger support for variable reference aliases Date: Mon, 26 Jun 2017 17:49:29 -0500 Message-Id: X-Mailer: git-send-email 1.9.3 In-Reply-To: References: In-Reply-To: References: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3331 Lines: 103 Add support for alias=$somevar where alias can be used as onmatch($alias). Signed-off-by: Tom Zanussi --- kernel/trace/trace_events_hist.c | 46 +++++++++++++++++++++++++++++++++++++--- 1 file changed, 43 insertions(+), 3 deletions(-) diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c index 904a635..799b95e 100644 --- a/kernel/trace/trace_events_hist.c +++ b/kernel/trace/trace_events_hist.c @@ -225,6 +225,7 @@ enum hist_field_flags { HIST_FIELD_FL_EXPR = 16384, HIST_FIELD_FL_VAR_REF = 32768, HIST_FIELD_FL_CPU = 65536, + HIST_FIELD_FL_ALIAS = 131072, }; struct hist_trigger_attrs { @@ -1414,7 +1415,8 @@ static const char *hist_field_name(struct hist_field *field, if (field->field) field_name = field->field->name; - else if (field->flags & HIST_FIELD_FL_LOG2) + else if (field->flags & HIST_FIELD_FL_LOG2 || + field->flags & HIST_FIELD_FL_ALIAS) field_name = hist_field_name(field->operands[0], ++level); else if (field->flags & HIST_FIELD_FL_TIMESTAMP) field_name = "$common_timestamp"; @@ -1819,7 +1821,7 @@ static struct hist_field *create_hist_field(struct hist_trigger_data *hist_data, hist_field->hist_data = hist_data; - if (flags & HIST_FIELD_FL_EXPR) + if (flags & HIST_FIELD_FL_EXPR || flags & HIST_FIELD_FL_ALIAS) goto out; /* caller will populate */ if (flags & HIST_FIELD_FL_VAR_REF) { @@ -2013,6 +2015,34 @@ static struct hist_field *parse_var_ref(char *system, char *event_name, return field; } +static struct hist_field *create_alias(struct hist_trigger_data *hist_data, + struct hist_field *var_ref, + char *var_name) +{ + struct hist_field *alias = NULL; + unsigned long flags = HIST_FIELD_FL_ALIAS | HIST_FIELD_FL_VAR | + HIST_FIELD_FL_VAR_ONLY; + + alias = create_hist_field(hist_data, NULL, flags, var_name); + if (!alias) + return NULL; + + alias->fn = var_ref->fn; + alias->operands[0] = var_ref; + alias->var.idx = var_ref->var.idx; + alias->var.hist_data = var_ref->hist_data; + alias->size = var_ref->size; + alias->is_signed = var_ref->is_signed; + alias->type = kstrdup(var_ref->type, GFP_KERNEL); + if (!alias->type) { + kfree(alias->type); + destroy_hist_field(alias, 0); + return NULL; + } + + return alias; +} + struct hist_field *parse_atom(struct hist_trigger_data *hist_data, struct trace_event_file *file, char *str, unsigned long *flags, char *var_name) @@ -2036,6 +2066,13 @@ struct hist_field *parse_atom(struct hist_trigger_data *hist_data, if (hist_field) { hist_data->var_refs[hist_data->n_var_refs] = hist_field; hist_field->var_ref_idx = hist_data->n_var_refs++; + if (var_name) { + hist_field = create_alias(hist_data, hist_field, var_name); + if (!hist_field) { + ret = -ENOMEM; + goto out; + } + } return hist_field; } @@ -4152,8 +4189,11 @@ static void hist_field_print(struct seq_file *m, struct hist_field *hist_field) seq_puts(m, "$common_timestamp"); else if (hist_field->flags & HIST_FIELD_FL_CPU) seq_puts(m, "cpu"); - else if (field_name) + else if (field_name) { + if (hist_field->flags & HIST_FIELD_FL_ALIAS) + seq_putc(m, '$'); seq_printf(m, "%s", field_name); + } if (hist_field->flags) { const char *flags_str = get_hist_field_flags(hist_field); -- 1.9.3