From patchwork Mon Dec 2 08:35:15 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Zhang Yi X-Patchwork-Id: 11268791 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id D65D4109A for ; Mon, 2 Dec 2019 08:14:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id BE30620833 for ; Mon, 2 Dec 2019 08:14:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727453AbfLBIOu (ORCPT ); Mon, 2 Dec 2019 03:14:50 -0500 Received: from szxga06-in.huawei.com ([45.249.212.32]:37320 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726254AbfLBIOX (ORCPT ); Mon, 2 Dec 2019 03:14:23 -0500 Received: from DGGEMS405-HUB.china.huawei.com (unknown [172.30.72.59]) by Forcepoint Email with ESMTP id 90F8DFAE075D8D407738; Mon, 2 Dec 2019 16:14:17 +0800 (CST) Received: from huawei.com (10.175.124.28) by DGGEMS405-HUB.china.huawei.com (10.3.19.205) with Microsoft SMTP Server id 14.3.439.0; Mon, 2 Dec 2019 16:14:10 +0800 From: "zhangyi (F)" To: CC: , , , , , , , , , , , Subject: [PATCH 4.4 3/7] sched/core, x86: Make struct thread_info arch specific again Date: Mon, 2 Dec 2019 16:35:15 +0800 Message-ID: <20191202083519.23138-4-yi.zhang@huawei.com> X-Mailer: git-send-email 2.17.2 In-Reply-To: <20191202083519.23138-1-yi.zhang@huawei.com> References: <20191202083519.23138-1-yi.zhang@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.175.124.28] X-CFilter-Loop: Reflected Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org From: Heiko Carstens commit c8061485a0d7569a865a3cc3c63347b0f42b3765 upstream. The following commit: c65eacbe290b ("sched/core: Allow putting thread_info into task_struct") ... made 'struct thread_info' a generic struct with only a single ::flags member, if CONFIG_THREAD_INFO_IN_TASK_STRUCT=y is selected. This change however seems to be quite x86 centric, since at least the generic preemption code (asm-generic/preempt.h) assumes that struct thread_info also has a preempt_count member, which apparently was not true for x86. We could add a bit more #ifdefs to solve this problem too, but it seems to be much simpler to make struct thread_info arch specific again. This also makes the conversion to THREAD_INFO_IN_TASK_STRUCT a bit easier for architectures that have a couple of arch specific stuff in their thread_info definition. The arch specific stuff _could_ be moved to thread_struct. However keeping them in thread_info makes it easier: accessing thread_info members is simple, since it is at the beginning of the task_struct, while the thread_struct is at the end. At least on s390 the offsets needed to access members of the thread_struct (with task_struct as base) are too large for various asm instructions. This is not a problem when keeping these members within thread_info. Signed-off-by: Heiko Carstens Signed-off-by: Mark Rutland Acked-by: Thomas Gleixner Cc: Andrew Morton Cc: Andy Lutomirski Cc: Linus Torvalds Cc: Peter Zijlstra Cc: keescook@chromium.org Cc: linux-arch@vger.kernel.org Link: http://lkml.kernel.org/r/1476901693-8492-2-git-send-email-mark.rutland@arm.com Signed-off-by: Ingo Molnar [ zhangyi: skip defination of INIT_THREAD_INFO and struct thread_info ] Signed-off-by: zhangyi (F) --- include/linux/thread_info.h | 11 ----------- 1 file changed, 11 deletions(-) diff --git a/include/linux/thread_info.h b/include/linux/thread_info.h index 2813de75a96e..897e835379d8 100644 --- a/include/linux/thread_info.h +++ b/include/linux/thread_info.h @@ -13,17 +13,6 @@ struct timespec; struct compat_timespec; -#ifdef CONFIG_THREAD_INFO_IN_TASK -struct thread_info { - u32 flags; /* low level flags */ -}; - -#define INIT_THREAD_INFO(tsk) \ -{ \ - .flags = 0, \ -} -#endif - #ifdef CONFIG_THREAD_INFO_IN_TASK #define current_thread_info() ((struct thread_info *)current) #endif