From patchwork Tue Sep 14 12:10:33 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ard Biesheuvel X-Patchwork-Id: 1527873 Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Authentication-Results: ozlabs.org; dkim=fail reason="signature verification failed" (2048-bit key; unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20201202 header.b=TzJIvOEI; dkim-atps=neutral Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=lists.ozlabs.org (client-ip=2404:9400:2:0:216:3eff:fee1:b9f1; helo=lists.ozlabs.org; envelope-from=linuxppc-dev-bounces+patchwork-incoming=ozlabs.org@lists.ozlabs.org; receiver=) Received: from lists.ozlabs.org (lists.ozlabs.org [IPv6:2404:9400:2:0:216:3eff:fee1:b9f1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 4H82Mb64Jmz9tkb for ; Tue, 14 Sep 2021 22:14:19 +1000 (AEST) Received: from boromir.ozlabs.org (localhost [IPv6:::1]) by lists.ozlabs.org (Postfix) with ESMTP id 4H82Mb4dznz3c6C for ; Tue, 14 Sep 2021 22:14:19 +1000 (AEST) Authentication-Results: lists.ozlabs.org; dkim=fail reason="signature verification failed" (2048-bit key; unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20201202 header.b=TzJIvOEI; dkim-atps=neutral X-Original-To: linuxppc-dev@lists.ozlabs.org Delivered-To: linuxppc-dev@lists.ozlabs.org Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=kernel.org (client-ip=198.145.29.99; helo=mail.kernel.org; envelope-from=ardb@kernel.org; receiver=) Authentication-Results: lists.ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20201202 header.b=TzJIvOEI; dkim-atps=neutral Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4H82J65gcCz2ywg for ; Tue, 14 Sep 2021 22:11:18 +1000 (AEST) Received: by mail.kernel.org (Postfix) with ESMTPSA id D2DEE6103B; Tue, 14 Sep 2021 12:11:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1631621476; bh=Kj7AdLjk9dRbSxRbhe4+hhQ+UqbNDKHemx+IxWmvoNc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=TzJIvOEIOpmXfZwzK1fGcRtZ1AJ6gHdJFZonxAsu5yeb23QMvOAZzgn1jTzcmC7D7 Y9Xp3JLFCqSwMg5yNBekuYixSeGJMle39ftqovV11b595vCe/uW+RHR95JUi+C9gQt dfETGkTcetXFVM/ZUM+dKpKs5tU03Gv1Y/puwrlMZfPn482RfB3f//qcjM/UJAZ4Fr Rs5ZVsZ8nxd9GFp9Hr1MXlQspsUSdK/0zEqqdeEA5eq44sKGlbNlGWTVSSw0T6KULy ZI/b3XkNSeKGjVoAf7GKdLo5Xy9/dk6eYbIqXvYas4SoJMTczY+lrh3JhVBdzUgoCJ axau0kIfnkywg== From: Ard Biesheuvel To: linux-kernel@vger.kernel.org Subject: [RFC PATCH 5/8] sched: move CPU field back into thread_info if THREAD_INFO_IN_TASK=y Date: Tue, 14 Sep 2021 14:10:33 +0200 Message-Id: <20210914121036.3975026-6-ardb@kernel.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210914121036.3975026-1-ardb@kernel.org> References: <20210914121036.3975026-1-ardb@kernel.org> MIME-Version: 1.0 X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Peter Zijlstra , Paul Mackerras , linux-riscv@lists.infradead.org, Will Deacon , Ard Biesheuvel , linux-s390@vger.kernel.org, Arnd Bergmann , Russell King , Christian Borntraeger , Ingo Molnar , Catalin Marinas , Albert Ou , Kees Cook , Vasily Gorbik , Heiko Carstens , Keith Packard , Borislav Petkov , Andy Lutomirski , Paul Walmsley , Thomas Gleixner , linux-arm-kernel@lists.infradead.org, linuxppc-dev@lists.ozlabs.org, Palmer Dabbelt , Linus Torvalds Errors-To: linuxppc-dev-bounces+patchwork-incoming=ozlabs.org@lists.ozlabs.org Sender: "Linuxppc-dev" 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. Signed-off-by: Ard Biesheuvel Acked-by: Catalin Marinas --- 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 | 6 +----- kernel/sched/sched.h | 4 ---- 6 files changed, 4 insertions(+), 13 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] 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 diff --git a/arch/powerpc/kernel/smp.c b/arch/powerpc/kernel/smp.c index 9cc7d3dbf439..512d875b45e0 100644 --- a/arch/powerpc/kernel/smp.c +++ b/arch/powerpc/kernel/smp.c @@ -1223,7 +1223,7 @@ static void cpu_idle_thread_init(unsigned int cpu, struct task_struct *idle) paca_ptrs[cpu]->kstack = (unsigned long)task_stack_page(idle) + THREAD_SIZE - STACK_FRAME_OVERHEAD; #endif - idle->cpu = cpu; + task_thread_info(idle)->cpu = cpu; secondary_current = current_set[cpu] = idle; } diff --git a/include/linux/sched.h b/include/linux/sched.h index e12b524426b0..37aa521078e7 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -750,10 +750,6 @@ struct task_struct { #ifdef CONFIG_SMP int on_cpu; struct __call_single_node wake_entry; -#ifdef CONFIG_THREAD_INFO_IN_TASK - /* Current CPU: */ - unsigned int cpu; -#endif unsigned int wakee_flips; unsigned long wakee_flip_decay_ts; struct task_struct *last_wakee; @@ -2114,7 +2110,7 @@ static __always_inline bool need_resched(void) static inline unsigned int task_cpu(const struct task_struct *p) { #ifdef CONFIG_THREAD_INFO_IN_TASK - return READ_ONCE(p->cpu); + return READ_ONCE(p->thread_info.cpu); #else return READ_ONCE(task_thread_info(p)->cpu); #endif diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h index 3d3e5793e117..79fcbad11450 100644 --- a/kernel/sched/sched.h +++ b/kernel/sched/sched.h @@ -1926,11 +1926,7 @@ static inline void __set_task_cpu(struct task_struct *p, unsigned int cpu) * per-task data have been completed by this moment. */ smp_wmb(); -#ifdef CONFIG_THREAD_INFO_IN_TASK - WRITE_ONCE(p->cpu, cpu); -#else WRITE_ONCE(task_thread_info(p)->cpu, cpu); -#endif p->wake_cpu = cpu; #endif }