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 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8A2F6C433EF for ; Thu, 30 Sep 2021 13:09:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 710526126A for ; Thu, 30 Sep 2021 13:09:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1348773AbhI3NKm (ORCPT ); Thu, 30 Sep 2021 09:10:42 -0400 Received: from pegase2.c-s.fr ([93.17.235.10]:59657 "EHLO pegase2.c-s.fr" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235496AbhI3NKl (ORCPT ); Thu, 30 Sep 2021 09:10:41 -0400 Received: from localhost (mailhub3.si.c-s.fr [172.26.127.67]) by localhost (Postfix) with ESMTP id 4HKtqF6rlCz9sTd; Thu, 30 Sep 2021 15:08:57 +0200 (CEST) X-Virus-Scanned: amavisd-new at c-s.fr Received: from pegase2.c-s.fr ([172.26.127.65]) by localhost (pegase2.c-s.fr [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id uup-HwASZHAe; Thu, 30 Sep 2021 15:08:57 +0200 (CEST) Received: from messagerie.si.c-s.fr (messagerie.si.c-s.fr [192.168.25.192]) by pegase2.c-s.fr (Postfix) with ESMTP id 4HKtqF5fKsz9sTF; Thu, 30 Sep 2021 15:08:57 +0200 (CEST) Received: from localhost (localhost [127.0.0.1]) by messagerie.si.c-s.fr (Postfix) with ESMTP id AAE588B773; Thu, 30 Sep 2021 15:08:57 +0200 (CEST) X-Virus-Scanned: amavisd-new at c-s.fr Received: from messagerie.si.c-s.fr ([127.0.0.1]) by localhost (messagerie.si.c-s.fr [127.0.0.1]) (amavisd-new, port 10023) with ESMTP id azUS0K5khefq; Thu, 30 Sep 2021 15:08:57 +0200 (CEST) Received: from PO20335.IDSI0.si.c-s.fr (unknown [192.168.203.149]) by messagerie.si.c-s.fr (Postfix) with ESMTP id 9E67B8B763; Thu, 30 Sep 2021 15:08:56 +0200 (CEST) Subject: Re: [PATCH v2 5/7] sched: move CPU field back into thread_info if THREAD_INFO_IN_TASK=y To: Ard Biesheuvel , linux-kernel@vger.kernel.org Cc: Keith Packard , Russell King , Catalin Marinas , Will Deacon , Michael Ellerman , Benjamin Herrenschmidt , Paul Mackerras , Paul Walmsley , Palmer Dabbelt , Albert Ou , Heiko Carstens , Mark Rutland References: <20210930125813.197418-1-ardb@kernel.org> <20210930125813.197418-6-ardb@kernel.org> From: Christophe Leroy Message-ID: <427566ca-80c0-56eb-880b-908bd4a71e9a@csgroup.eu> Date: Thu, 30 Sep 2021 15:08:56 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.11.0 MIME-Version: 1.0 In-Reply-To: <20210930125813.197418-6-ardb@kernel.org> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: fr-FR Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Le 30/09/2021 à 14:58, Ard Biesheuvel a écrit : > THREAD_INFO_IN_TASK moved the CPU field out of thread_info, but this > causes some issues on architectures that define raw_smp_processor_id() > in terms of this field, due to the fact that #include'ing linux/sched.h > to get at struct task_struct is problematic in terms of circular > dependencies. > > Given that thread_info and task_struct are the same data structure > anyway when THREAD_INFO_IN_TASK=y, let's move it back so that having > access to the type definition of struct thread_info is sufficient to > reference the CPU number of the current task. > > Note that this requires THREAD_INFO_IN_TASK's definition of the > task_thread_info() helper to be updated, as task_cpu() takes a > pointer-to-const, whereas task_thread_info() (which is used to generate > lvalues as well), needs a non-const pointer. So make it a macro instead. > > Signed-off-by: Ard Biesheuvel > Acked-by: Catalin Marinas > Acked-by: Mark Rutland > Acked-by: Michael Ellerman > --- > arch/arm64/kernel/asm-offsets.c | 1 - > arch/arm64/kernel/head.S | 2 +- > arch/powerpc/kernel/asm-offsets.c | 2 +- > arch/powerpc/kernel/smp.c | 2 +- > include/linux/sched.h | 13 +------------ > kernel/sched/sched.h | 4 ---- > 6 files changed, 4 insertions(+), 20 deletions(-) > > diff --git a/arch/arm64/kernel/asm-offsets.c b/arch/arm64/kernel/asm-offsets.c > index cee9f3e9f906..0bfc048221af 100644 > --- a/arch/arm64/kernel/asm-offsets.c > +++ b/arch/arm64/kernel/asm-offsets.c > @@ -27,7 +27,6 @@ > int main(void) > { > DEFINE(TSK_ACTIVE_MM, offsetof(struct task_struct, active_mm)); > - DEFINE(TSK_CPU, offsetof(struct task_struct, cpu)); > BLANK(); > DEFINE(TSK_TI_CPU, offsetof(struct task_struct, thread_info.cpu)); > DEFINE(TSK_TI_FLAGS, offsetof(struct task_struct, thread_info.flags)); > diff --git a/arch/arm64/kernel/head.S b/arch/arm64/kernel/head.S > index 17962452e31d..6a98f1a38c29 100644 > --- a/arch/arm64/kernel/head.S > +++ b/arch/arm64/kernel/head.S > @@ -412,7 +412,7 @@ SYM_FUNC_END(__create_page_tables) > scs_load \tsk > > adr_l \tmp1, __per_cpu_offset > - ldr w\tmp2, [\tsk, #TSK_CPU] > + ldr w\tmp2, [\tsk, #TSK_TI_CPU] Why do you need to change the name ? For powerpc64, you leave TASK_CPU. > ldr \tmp1, [\tmp1, \tmp2, lsl #3] > set_this_cpu_offset \tmp1 > .endm > diff --git a/arch/powerpc/kernel/asm-offsets.c b/arch/powerpc/kernel/asm-offsets.c > index e563d3222d69..e37e4546034e 100644 > --- a/arch/powerpc/kernel/asm-offsets.c > +++ b/arch/powerpc/kernel/asm-offsets.c > @@ -93,7 +93,7 @@ int main(void) > #endif /* CONFIG_PPC64 */ > OFFSET(TASK_STACK, task_struct, stack); > #ifdef CONFIG_SMP > - OFFSET(TASK_CPU, task_struct, cpu); > + OFFSET(TASK_CPU, task_struct, thread_info.cpu); > #endif > > #ifdef CONFIG_LIVEPATCH ...