From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id BC5D32C0F95; Wed, 15 Oct 2025 08:27:48 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760516870; cv=none; b=nAjZI1EAUWncWiBDF1WvhCRZclIKG/rpEtI/Hc+SSY9XYACRsdRyLwVaVEi1eoaz5WvMcktGl2SvBErpLe9S8B34qv6LXyVSYivMIC5k1igfODnyxP7+G1gKY9U7zY6bt0vl/0dPkbNBkuN+86QCK9w9hdQ7LV+7uUsxsFzDg5o= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760516870; c=relaxed/simple; bh=X7IHf19fA6/hC1xo7yaV++jcdwAE28tbT+JGDTOI2QA=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=iuazjaXva5wj5cF+7E3Mr5JUpteQWYk/m7TB0e+XxulqNOaMu7eAa9aHhqgaUFsJfzK0UX1efyoPBgGRa9TilpFYbjZVxqq94r83VuJPOxYyQhTJ4X4pQ2/1wU8GU+5RvnwMatHL+x9+pX4vNC7DcdG2svXfHdZpPYj06aeAYek= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id EE70F1A9A; Wed, 15 Oct 2025 01:27:39 -0700 (PDT) Received: from e123572-lin.arm.com (e123572-lin.cambridge.arm.com [10.1.194.54]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id EB26A3F66E; Wed, 15 Oct 2025 01:27:42 -0700 (PDT) From: Kevin Brodsky To: linux-mm@kvack.org Cc: linux-kernel@vger.kernel.org, Kevin Brodsky , Alexander Gordeev , Andreas Larsson , Andrew Morton , Boris Ostrovsky , Borislav Petkov , Catalin Marinas , Christophe Leroy , Dave Hansen , David Hildenbrand , "David S. Miller" , "H. Peter Anvin" , Ingo Molnar , Jann Horn , Juergen Gross , "Liam R. Howlett" , Lorenzo Stoakes , Madhavan Srinivasan , Michael Ellerman , Michal Hocko , Mike Rapoport , Nicholas Piggin , Peter Zijlstra , Ryan Roberts , Suren Baghdasaryan , Thomas Gleixner , Vlastimil Babka , Will Deacon , Yeoreum Yun , linux-arm-kernel@lists.infradead.org, linuxppc-dev@lists.ozlabs.org, sparclinux@vger.kernel.org, xen-devel@lists.xenproject.org, x86@kernel.org Subject: [PATCH v3 01/13] powerpc/64s: Do not re-activate batched TLB flush Date: Wed, 15 Oct 2025 09:27:15 +0100 Message-ID: <20251015082727.2395128-2-kevin.brodsky@arm.com> X-Mailer: git-send-email 2.47.0 In-Reply-To: <20251015082727.2395128-1-kevin.brodsky@arm.com> References: <20251015082727.2395128-1-kevin.brodsky@arm.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Alexander Gordeev Since commit b9ef323ea168 ("powerpc/64s: Disable preemption in hash lazy mmu mode") a task can not be preempted while in lazy MMU mode. Therefore, the batch re-activation code is never called, so remove it. Signed-off-by: Alexander Gordeev Signed-off-by: Kevin Brodsky --- This patch was originally posted as part of [1]; the series was not taken but this patch remains relevant. [1] https://lore.kernel.org/all/cover.1749747752.git.agordeev@linux.ibm.com/ --- arch/powerpc/include/asm/thread_info.h | 2 -- arch/powerpc/kernel/process.c | 25 ------------------------- 2 files changed, 27 deletions(-) diff --git a/arch/powerpc/include/asm/thread_info.h b/arch/powerpc/include/asm/thread_info.h index b0f200aba2b3..97f35f9b1a96 100644 --- a/arch/powerpc/include/asm/thread_info.h +++ b/arch/powerpc/include/asm/thread_info.h @@ -154,12 +154,10 @@ void arch_setup_new_exec(void); /* Don't move TLF_NAPPING without adjusting the code in entry_32.S */ #define TLF_NAPPING 0 /* idle thread enabled NAP mode */ #define TLF_SLEEPING 1 /* suspend code enabled SLEEP mode */ -#define TLF_LAZY_MMU 3 /* tlb_batch is active */ #define TLF_RUNLATCH 4 /* Is the runlatch enabled? */ #define _TLF_NAPPING (1 << TLF_NAPPING) #define _TLF_SLEEPING (1 << TLF_SLEEPING) -#define _TLF_LAZY_MMU (1 << TLF_LAZY_MMU) #define _TLF_RUNLATCH (1 << TLF_RUNLATCH) #ifndef __ASSEMBLER__ diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c index eb23966ac0a9..9237dcbeee4a 100644 --- a/arch/powerpc/kernel/process.c +++ b/arch/powerpc/kernel/process.c @@ -1281,9 +1281,6 @@ struct task_struct *__switch_to(struct task_struct *prev, { struct thread_struct *new_thread, *old_thread; struct task_struct *last; -#ifdef CONFIG_PPC_64S_HASH_MMU - struct ppc64_tlb_batch *batch; -#endif new_thread = &new->thread; old_thread = ¤t->thread; @@ -1291,14 +1288,6 @@ struct task_struct *__switch_to(struct task_struct *prev, WARN_ON(!irqs_disabled()); #ifdef CONFIG_PPC_64S_HASH_MMU - batch = this_cpu_ptr(&ppc64_tlb_batch); - if (batch->active) { - current_thread_info()->local_flags |= _TLF_LAZY_MMU; - if (batch->index) - __flush_tlb_pending(batch); - batch->active = 0; - } - /* * On POWER9 the copy-paste buffer can only paste into * foreign real addresses, so unprivileged processes can not @@ -1369,20 +1358,6 @@ struct task_struct *__switch_to(struct task_struct *prev, */ #ifdef CONFIG_PPC_BOOK3S_64 -#ifdef CONFIG_PPC_64S_HASH_MMU - /* - * This applies to a process that was context switched while inside - * arch_enter_lazy_mmu_mode(), to re-activate the batch that was - * deactivated above, before _switch(). This will never be the case - * for new tasks. - */ - if (current_thread_info()->local_flags & _TLF_LAZY_MMU) { - current_thread_info()->local_flags &= ~_TLF_LAZY_MMU; - batch = this_cpu_ptr(&ppc64_tlb_batch); - batch->active = 1; - } -#endif - /* * Math facilities are masked out of the child MSR in copy_thread. * A new task does not need to restore_math because it will -- 2.47.0