Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751462Ab3IQGRw (ORCPT ); Tue, 17 Sep 2013 02:17:52 -0400 Received: from hermes.synopsys.com ([198.182.44.81]:42574 "EHLO hermes.synopsys.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751247Ab3IQGRs (ORCPT ); Tue, 17 Sep 2013 02:17:48 -0400 From: Vineet Gupta To: Ingo Molnar , Peter Zijlstra , Andrew Morton CC: Subject: [RFC PATCH REBASED 0/3] Move ARCH specific fpu_counter out of task_struct Date: Tue, 17 Sep 2013 11:47:16 +0530 Message-ID: <1379398639-27403-1-git-send-email-vgupta@synopsys.com> X-Mailer: git-send-email 1.8.1.2 MIME-Version: 1.0 Content-Type: text/plain X-Originating-IP: [10.12.197.111] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1910 Lines: 51 Hi, This is a resend of the patches I sent last week which failed to draw any attention. This basically came up when ARC SMP 3.11 failed to build due to a ST insn dealing with task_struct.thread going out of range. When staring at code I spotted @fpu_counter in task_struct which only SH/x86 happen to use, and can be easily moved out into corresponding ARCH specific thread_struct. This saves 4 bytes per task_struct instantiated, for all the other 18 arches. One of the resistance to the patch(es) could be that task_struct fields were at some point arranged to reduce the number of line misses. However there is lot of variance there due to so many #ifdefs, variable size of cpumask (>32 cores..) etc, so that argument alone might not be sufficient vs. saving 4 bytes per instance. Comments please ! Thx, -Vineet Vineet Gupta (3): sh: Move fpu_counter into ARCH specific thread_struct x86: Move fpu_counter into ARCH specific thread_struct sched: Remove ARCH specific fpu_counter from task_struct arch/sh/include/asm/fpu.h | 2 +- arch/sh/include/asm/processor_32.h | 10 ++++++++++ arch/sh/include/asm/processor_64.h | 10 ++++++++++ arch/sh/kernel/cpu/fpu.c | 2 +- arch/sh/kernel/process_32.c | 6 +++--- arch/x86/include/asm/fpu-internal.h | 10 +++++----- arch/x86/include/asm/processor.h | 9 +++++++++ arch/x86/kernel/i387.c | 2 +- arch/x86/kernel/process_32.c | 4 ++-- arch/x86/kernel/process_64.c | 2 +- arch/x86/kernel/traps.c | 2 +- include/linux/sched.h | 9 --------- 12 files changed, 44 insertions(+), 24 deletions(-) -- 1.8.1.2 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/