From patchwork Mon Jul 4 13:14:36 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Steven Rostedt X-Patchwork-Id: 12905351 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 99A9ACCA479 for ; Mon, 4 Jul 2022 13:14:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234445AbiGDNOz (ORCPT ); Mon, 4 Jul 2022 09:14:55 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53816 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234664AbiGDNOm (ORCPT ); Mon, 4 Jul 2022 09:14:42 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C44C3638A; Mon, 4 Jul 2022 06:14:39 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 6111C614C4; Mon, 4 Jul 2022 13:14:39 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id AF813C3411E; Mon, 4 Jul 2022 13:14:37 +0000 (UTC) Date: Mon, 4 Jul 2022 09:14:36 -0400 From: Steven Rostedt To: LKML Cc: David Ahern , "David S. Miller" , netdev Subject: [PATCH v2] tracing/ipv4/ipv6: Use static array for name field in fib*_lookup_table event Message-ID: <20220704091436.3705edbf@rorschach.local.home> X-Mailer: Claws Mail 3.17.8 (GTK+ 2.24.33; x86_64-pc-linux-gnu) MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: "Steven Rostedt (Google)" The fib_lookup_table and fib6_lookup_table events declare name as a dynamic_array, but also give it a fixed size, which defeats the purpose of the dynamic array, especially since the dynamic array also includes meta data in the event to specify its size. Since the size of the name is at most 16 bytes (defined by IFNAMSIZ), it is not worth spending the effort to determine the size of the string. Just use a fixed size array and copy into it. This will save 4 bytes that are used for the meta data that saves the size and position of a dynamic array, and even slightly speed up the event processing. Cc: David Ahern Cc: David S. Miller Cc: netdev@vger.kernel.org Signed-off-by: Steven Rostedt (Google) Reviewed-by: David Ahern Acked-by: Jakub Kicinski --- Changes since v1: https://lkml.kernel.org/r/20220703102359.30f12e39@rorschach.local.home - Just use a fixed size array instead of calculating the size needed for the dynamic allocation. include/trace/events/fib.h | 6 +++--- include/trace/events/fib6.h | 8 ++++---- 2 files changed, 7 insertions(+), 7 deletions(-) diff --git a/include/trace/events/fib.h b/include/trace/events/fib.h index 6f2a4dc35e37..c2300c407f58 100644 --- a/include/trace/events/fib.h +++ b/include/trace/events/fib.h @@ -32,7 +32,7 @@ TRACE_EVENT(fib_table_lookup, __array( __u8, gw6, 16 ) __field( u16, sport ) __field( u16, dport ) - __dynamic_array(char, name, IFNAMSIZ ) + __array(char, name, IFNAMSIZ ) ), TP_fast_assign( @@ -66,7 +66,7 @@ TRACE_EVENT(fib_table_lookup, } dev = nhc ? nhc->nhc_dev : NULL; - __assign_str(name, dev ? dev->name : "-"); + strlcpy(__entry->name, dev ? dev->name : "-", IFNAMSIZ); if (nhc) { if (nhc->nhc_gw_family == AF_INET) { @@ -95,7 +95,7 @@ TRACE_EVENT(fib_table_lookup, __entry->tb_id, __entry->oif, __entry->iif, __entry->proto, __entry->src, __entry->sport, __entry->dst, __entry->dport, __entry->tos, __entry->scope, __entry->flags, - __get_str(name), __entry->gw4, __entry->gw6, __entry->err) + __entry->name, __entry->gw4, __entry->gw6, __entry->err) ); #endif /* _TRACE_FIB_H */ diff --git a/include/trace/events/fib6.h b/include/trace/events/fib6.h index c6abdcc77c12..6e821eb79450 100644 --- a/include/trace/events/fib6.h +++ b/include/trace/events/fib6.h @@ -31,7 +31,7 @@ TRACE_EVENT(fib6_table_lookup, __field( u16, dport ) __field( u8, proto ) __field( u8, rt_type ) - __dynamic_array( char, name, IFNAMSIZ ) + __array( char, name, IFNAMSIZ ) __array( __u8, gw, 16 ) ), @@ -63,9 +63,9 @@ TRACE_EVENT(fib6_table_lookup, } if (res->nh && res->nh->fib_nh_dev) { - __assign_str(name, res->nh->fib_nh_dev); + strlcpy(__entry->name, res->nh->fib_nh_dev->name, IFNAMSIZ); } else { - __assign_str(name, "-"); + strcpy(__entry->name, "-"); } if (res->f6i == net->ipv6.fib6_null_entry) { struct in6_addr in6_zero = {}; @@ -83,7 +83,7 @@ TRACE_EVENT(fib6_table_lookup, __entry->tb_id, __entry->oif, __entry->iif, __entry->proto, __entry->src, __entry->sport, __entry->dst, __entry->dport, __entry->tos, __entry->scope, __entry->flags, - __get_str(name), __entry->gw, __entry->err) + __entry->name, __entry->gw, __entry->err) ); #endif /* _TRACE_FIB6_H */