From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932306AbcHSLxP (ORCPT ); Fri, 19 Aug 2016 07:53:15 -0400 Received: from mx1.redhat.com ([209.132.183.28]:54286 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932192AbcHSLxN (ORCPT ); Fri, 19 Aug 2016 07:53:13 -0400 From: Josh Poimboeuf To: Thomas Gleixner , Ingo Molnar , "H . Peter Anvin" Cc: x86@kernel.org, linux-kernel@vger.kernel.org, Andy Lutomirski , Linus Torvalds , Steven Rostedt , Brian Gerst , Kees Cook , Peter Zijlstra , Frederic Weisbecker , Byungchul Park , Nilay Vaish Subject: [PATCH 2/8] ftrace: only allocate the ret_stack 'fp' field when needed Date: Fri, 19 Aug 2016 06:52:56 -0500 Message-Id: <5c7747d9ea7b5cb47ef0a8ce8a6cea6bf7aa94bf.1471607358.git.jpoimboe@redhat.com> In-Reply-To: References: X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.30]); Fri, 19 Aug 2016 11:53:13 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This saves some memory when HAVE_FUNCTION_GRAPH_FP_TEST isn't defined. On x86_64 with newer versions of gcc which have -mfentry, it saves 400 bytes per task. Signed-off-by: Josh Poimboeuf --- include/linux/ftrace.h | 2 ++ kernel/trace/trace_functions_graph.c | 2 ++ 2 files changed, 4 insertions(+) diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h index 7d565af..4ad9ccc 100644 --- a/include/linux/ftrace.h +++ b/include/linux/ftrace.h @@ -795,7 +795,9 @@ struct ftrace_ret_stack { unsigned long func; unsigned long long calltime; unsigned long long subtime; +#ifdef HAVE_FUNCTION_GRAPH_FP_TEST unsigned long fp; +#endif }; /* diff --git a/kernel/trace/trace_functions_graph.c b/kernel/trace/trace_functions_graph.c index fc173cd..0e03ed0 100644 --- a/kernel/trace/trace_functions_graph.c +++ b/kernel/trace/trace_functions_graph.c @@ -171,7 +171,9 @@ ftrace_push_return_trace(unsigned long ret, unsigned long func, int *depth, current->ret_stack[index].func = func; current->ret_stack[index].calltime = calltime; current->ret_stack[index].subtime = 0; +#ifdef HAVE_FUNCTION_GRAPH_FP_TEST current->ret_stack[index].fp = frame_pointer; +#endif *depth = current->curr_ret_stack; return 0; -- 2.7.4