From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-17.7 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id E2887C63793 for ; Thu, 22 Jul 2021 15:24:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B87AE6109D for ; Thu, 22 Jul 2021 15:24:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232627AbhGVOoC (ORCPT ); Thu, 22 Jul 2021 10:44:02 -0400 Received: from mail.kernel.org ([198.145.29.99]:34186 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232465AbhGVOoB (ORCPT ); Thu, 22 Jul 2021 10:44:01 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 4B10861029; Thu, 22 Jul 2021 15:24:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1626967476; bh=D3DCd79KMbS6Af7mk2Jiy5QA+wt84B2YDIvpNYBuVqo=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=p6OZugovV5VEUJEDP6fSHCOwSxm4LNgKXZ79Iyd2oRgRvVEmtGNL63JxLcaD9T5tQ wU0998+H3c8n6jjep/bVikweNEs7NE5elVQOgy4t3VKxNwrZOsJyiO96A8MgmwfohX m9uiMxpi6Yigi1871t5p6mfyOPWsZWeQJhgmmMxm7PmiPAFuSm7h6CNsoMeXELHQdb gOezVmu6colPi4HZ4H5R8awdj+GnhZIWgLCDUFqAI6fFfTkVmyXY4OSmsY6Qs7a7fY 2wZTpZS1z1RIKBETxZmo8YVoYmvck6U9D/h+LkYMShiZLDbUVU/a3rs7e3Ii5ds8ZI QODVjwg/WgjWQ== Date: Fri, 23 Jul 2021 00:24:33 +0900 From: Masami Hiramatsu To: Steven Rostedt Cc: linux-kernel@vger.kernel.org, Ingo Molnar , Andrew Morton , Tom Zanussi , Masami Hiramatsu , Namhyung Kim Subject: Re: [PATCH v2 1/2] tracing: Have histogram types be constant when possible Message-Id: <20210723002433.8abeddba573035f0b7b21739@kernel.org> In-Reply-To: <20210722142837.280718447@goodmis.org> References: <20210722142705.992001628@goodmis.org> <20210722142837.280718447@goodmis.org> X-Mailer: Sylpheed 3.7.0 (GTK+ 2.24.32; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 22 Jul 2021 10:27:06 -0400 Steven Rostedt wrote: > From: "Steven Rostedt (VMware)" > > Instead of kstrdup("const", GFP_KERNEL), have the hist_field type simply > assign the constant hist_field->type = "const"; And when the value passed > to it is a variable, use "kstrdup_const(var, GFP_KERNEL);" which will just > copy the value if the variable is already a constant. This saves on having > to allocate when not needed. > > All frees of the hist_field->type will need to use kfree_const(). > Thanks! This looks good to me. Reviewed-by: Masami Hiramatsu > Suggested-by: Masami Hiramatsu > Signed-off-by: Steven Rostedt (VMware) > --- > kernel/trace/trace_events_hist.c | 32 ++++++++++++++------------------ > 1 file changed, 14 insertions(+), 18 deletions(-) > > diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c > index 34325f41ebc0..5c9082201bc2 100644 > --- a/kernel/trace/trace_events_hist.c > +++ b/kernel/trace/trace_events_hist.c > @@ -1589,7 +1589,9 @@ static void __destroy_hist_field(struct hist_field *hist_field) > > kfree(hist_field->var.name); > kfree(hist_field->name); > - kfree(hist_field->type); > + > + /* Can likely be a const */ > + kfree_const(hist_field->type); > > kfree(hist_field->system); > kfree(hist_field->event_name); > @@ -1646,9 +1648,7 @@ static struct hist_field *create_hist_field(struct hist_trigger_data *hist_data, > if (flags & HIST_FIELD_FL_HITCOUNT) { > hist_field->fn = hist_field_counter; > hist_field->size = sizeof(u64); > - hist_field->type = kstrdup("u64", GFP_KERNEL); > - if (!hist_field->type) > - goto free; > + hist_field->type = "u64"; > goto out; > } > > @@ -1662,7 +1662,7 @@ static struct hist_field *create_hist_field(struct hist_trigger_data *hist_data, > hist_field->fn = hist_field_log2; > hist_field->operands[0] = create_hist_field(hist_data, field, fl, NULL); > hist_field->size = hist_field->operands[0]->size; > - hist_field->type = kstrdup(hist_field->operands[0]->type, GFP_KERNEL); > + hist_field->type = kstrdup_const(hist_field->operands[0]->type, GFP_KERNEL); > if (!hist_field->type) > goto free; > goto out; > @@ -1671,18 +1671,14 @@ static struct hist_field *create_hist_field(struct hist_trigger_data *hist_data, > if (flags & HIST_FIELD_FL_TIMESTAMP) { > hist_field->fn = hist_field_timestamp; > hist_field->size = sizeof(u64); > - hist_field->type = kstrdup("u64", GFP_KERNEL); > - if (!hist_field->type) > - goto free; > + hist_field->type = "u64"; > goto out; > } > > if (flags & HIST_FIELD_FL_CPU) { > hist_field->fn = hist_field_cpu; > hist_field->size = sizeof(int); > - hist_field->type = kstrdup("unsigned int", GFP_KERNEL); > - if (!hist_field->type) > - goto free; > + hist_field->type = "unsigned int"; > goto out; > } > > @@ -1695,7 +1691,7 @@ static struct hist_field *create_hist_field(struct hist_trigger_data *hist_data, > flags |= HIST_FIELD_FL_STRING; > > hist_field->size = MAX_FILTER_STR_VAL; > - hist_field->type = kstrdup(field->type, GFP_KERNEL); > + hist_field->type = kstrdup_const(field->type, GFP_KERNEL); > if (!hist_field->type) > goto free; > > @@ -1708,7 +1704,7 @@ static struct hist_field *create_hist_field(struct hist_trigger_data *hist_data, > } else { > hist_field->size = field->size; > hist_field->is_signed = field->is_signed; > - hist_field->type = kstrdup(field->type, GFP_KERNEL); > + hist_field->type = kstrdup_const(field->type, GFP_KERNEL); > if (!hist_field->type) > goto free; > > @@ -1794,7 +1790,7 @@ static int init_var_ref(struct hist_field *ref_field, > } > } > > - ref_field->type = kstrdup(var_field->type, GFP_KERNEL); > + ref_field->type = kstrdup_const(var_field->type, GFP_KERNEL); > if (!ref_field->type) { > err = -ENOMEM; > goto free; > @@ -2163,7 +2159,7 @@ static struct hist_field *parse_unary(struct hist_trigger_data *hist_data, > expr->operands[0] = operand1; > expr->operator = FIELD_OP_UNARY_MINUS; > expr->name = expr_str(expr, 0); > - expr->type = kstrdup(operand1->type, GFP_KERNEL); > + expr->type = kstrdup_const(operand1->type, GFP_KERNEL); > if (!expr->type) { > ret = -ENOMEM; > goto free; > @@ -2289,7 +2285,7 @@ static struct hist_field *parse_expr(struct hist_trigger_data *hist_data, > expr->operands[1] = operand2; > expr->operator = field_op; > expr->name = expr_str(expr, 0); > - expr->type = kstrdup(operand1->type, GFP_KERNEL); > + expr->type = kstrdup_const(operand1->type, GFP_KERNEL); > if (!expr->type) { > ret = -ENOMEM; > goto free; > @@ -2677,10 +2673,10 @@ static struct hist_field *create_var(struct hist_trigger_data *hist_data, > var->var.hist_data = var->hist_data = hist_data; > var->size = size; > var->var.name = kstrdup(name, GFP_KERNEL); > - var->type = kstrdup(type, GFP_KERNEL); > + var->type = kstrdup_const(type, GFP_KERNEL); > if (!var->var.name || !var->type) { > + kfree_const(var->type); > kfree(var->var.name); > - kfree(var->type); > kfree(var); > var = ERR_PTR(-ENOMEM); > } > -- > 2.30.2 -- Masami Hiramatsu