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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 3D33FCCF9F8 for ; Fri, 7 Nov 2025 13:56:31 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 8AEFF8E0011; Fri, 7 Nov 2025 08:56:30 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 835D78E000D; Fri, 7 Nov 2025 08:56:30 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 7241F8E0011; Fri, 7 Nov 2025 08:56:30 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0016.hostedemail.com [216.40.44.16]) by kanga.kvack.org (Postfix) with ESMTP id 5874E8E000D for ; Fri, 7 Nov 2025 08:56:30 -0500 (EST) Received: from smtpin14.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay06.hostedemail.com (Postfix) with ESMTP id 226F012CA98 for ; Fri, 7 Nov 2025 13:56:30 +0000 (UTC) X-FDA: 84083960940.14.58309B8 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by imf23.hostedemail.com (Postfix) with ESMTP id E5048140009 for ; Fri, 7 Nov 2025 13:56:27 +0000 (UTC) Authentication-Results: imf23.hostedemail.com; dkim=none; dmarc=pass (policy=none) header.from=arm.com; spf=pass (imf23.hostedemail.com: domain of ryan.roberts@arm.com designates 217.140.110.172 as permitted sender) smtp.mailfrom=ryan.roberts@arm.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1762523788; a=rsa-sha256; cv=none; b=JNy0Jx2VxIPB/0MLIvrMCDIwIicoOmrlmk3IZhfs7utqit/d+zjlpJ1ClgFVc02Z/4tUrK 62e3QOIZtpD6B44+MpeHpt4OP/L6pe9e68NBibJwG1myEfVOMSGhhUJlJn56fOMsm6brik kcfTIetKHTayY2hj4PFfUSemcv3nt04= ARC-Authentication-Results: i=1; imf23.hostedemail.com; dkim=none; dmarc=pass (policy=none) header.from=arm.com; spf=pass (imf23.hostedemail.com: domain of ryan.roberts@arm.com designates 217.140.110.172 as permitted sender) smtp.mailfrom=ryan.roberts@arm.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1762523788; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=/N0zytyf9GWg2MCOYMZ3KiEnbTtu2OLzkkLJO68YSF4=; b=V5qDTPMsvv9XE3OCPjRSZgHqNbdjRMbL8fO6X8faabeqlTzXff4cdyph38kAhOrsQzhyLz qeIL52sQZc21d8dhZevF/qXuyigd1shzvAGPoTTettMrWxSOdUECc36pZ6Keo6uk5BrDm5 s2lE2tA4RGzUFDAwcYQkNbUuwqjEpm0= 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 F05461515; Fri, 7 Nov 2025 05:56:18 -0800 (PST) Received: from [10.57.86.134] (unknown [10.57.86.134]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 235F03F66E; Fri, 7 Nov 2025 05:56:22 -0800 (PST) Message-ID: <6a9c846f-22b6-4d5f-81dc-6cdcd4905952@arm.com> Date: Fri, 7 Nov 2025 13:56:20 +0000 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v4 05/12] mm: introduce CONFIG_ARCH_HAS_LAZY_MMU_MODE Content-Language: en-GB To: Kevin Brodsky , linux-mm@kvack.org Cc: linux-kernel@vger.kernel.org, Alexander Gordeev , Andreas Larsson , Andrew Morton , Boris Ostrovsky , Borislav Petkov , Catalin Marinas , Christophe Leroy , Dave Hansen , David Hildenbrand , "David S. Miller" , David Woodhouse , "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 , 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 References: <20251029100909.3381140-1-kevin.brodsky@arm.com> <20251029100909.3381140-6-kevin.brodsky@arm.com> From: Ryan Roberts In-Reply-To: <20251029100909.3381140-6-kevin.brodsky@arm.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Rspamd-Server: rspam06 X-Rspamd-Queue-Id: E5048140009 X-Stat-Signature: xgxocyf93ozp3k918hy64g71xnuhwnbq X-Rspam-User: X-HE-Tag: 1762523787-93395 X-HE-Meta: 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 Ya/RnYCM ZXhE3ImjRNfzI+983he/4jI9pO0EMUIsDnWjTMZAuZ2+tb/7hPzsuwdUI86Z3gomXKhccQndlZNMiswhU71R6xj4SM02rqhGxwcaqLi9captZ1S5XKI/OVRYzu42cjMkBr6MofknuZMlAnTdhpUuWtwn3vXhKuZ/sAnhmrSOlAnCniwoxzRlfD2dSKNjAkgfpL8iXEt2VvT9Xk230Sy+6mAVR3dPEoSvfoghg5NVde2v+gXgb+QXCF13gMsVwCgpKwh5e X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On 29/10/2025 10:09, Kevin Brodsky wrote: > Architectures currently opt in for implementing lazy_mmu helpers by > defining __HAVE_ARCH_ENTER_LAZY_MMU_MODE. > > In preparation for introducing a generic lazy_mmu layer that will > require storage in task_struct, let's switch to a cleaner approach: > instead of defining a macro, select a CONFIG option. > > This patch introduces CONFIG_ARCH_HAS_LAZY_MMU_MODE and has each > arch select it when it implements lazy_mmu helpers. > __HAVE_ARCH_ENTER_LAZY_MMU_MODE is removed and > relies on the new CONFIG instead. > > On x86, lazy_mmu helpers are only implemented if PARAVIRT_XXL is > selected. This creates some complications in arch/x86/boot/, because > a few files manually undefine PARAVIRT* options. As a result > does not define the lazy_mmu helpers, but this > breaks the build as only defines them if > !CONFIG_ARCH_HAS_LAZY_MMU_MODE. There does not seem to be a clean > way out of this - let's just undefine that new CONFIG too. > > Signed-off-by: Kevin Brodsky > --- > arch/arm64/Kconfig | 1 + > arch/arm64/include/asm/pgtable.h | 1 - > arch/powerpc/include/asm/book3s/64/tlbflush-hash.h | 2 -- > arch/powerpc/platforms/Kconfig.cputype | 1 + > arch/sparc/Kconfig | 1 + > arch/sparc/include/asm/tlbflush_64.h | 2 -- > arch/x86/Kconfig | 1 + > arch/x86/boot/compressed/misc.h | 1 + > arch/x86/boot/startup/sme.c | 1 + > arch/x86/include/asm/paravirt.h | 1 - > include/linux/pgtable.h | 2 +- > mm/Kconfig | 3 +++ > 12 files changed, 10 insertions(+), 7 deletions(-) > > diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig > index 6663ffd23f25..e6bf5c7311b5 100644 > --- a/arch/arm64/Kconfig > +++ b/arch/arm64/Kconfig > @@ -122,6 +122,7 @@ config ARM64 > select ARCH_WANTS_NO_INSTR > select ARCH_WANTS_THP_SWAP if ARM64_4K_PAGES > select ARCH_HAS_UBSAN > + select ARCH_HAS_LAZY_MMU_MODE nit: This list is mostly in alphabetical order. Further up the list there are a lot of ARCH_HAS_* entries. Perhaps move it to the correct position in that lot? Then ARCH_HAS_UBSAN stays out of order on its own. Otherwise, all looks reasonable to me: Reviewed-by: Ryan Roberts > select ARM_AMBA > select ARM_ARCH_TIMER > select ARM_GIC > diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h > index 0944e296dd4a..54f8d6bb6f22 100644 > --- a/arch/arm64/include/asm/pgtable.h > +++ b/arch/arm64/include/asm/pgtable.h > @@ -80,7 +80,6 @@ static inline void queue_pte_barriers(void) > } > } > > -#define __HAVE_ARCH_ENTER_LAZY_MMU_MODE > static inline void arch_enter_lazy_mmu_mode(void) > { > /* > diff --git a/arch/powerpc/include/asm/book3s/64/tlbflush-hash.h b/arch/powerpc/include/asm/book3s/64/tlbflush-hash.h > index 7704dbe8e88d..623a8a8b2d0e 100644 > --- a/arch/powerpc/include/asm/book3s/64/tlbflush-hash.h > +++ b/arch/powerpc/include/asm/book3s/64/tlbflush-hash.h > @@ -24,8 +24,6 @@ DECLARE_PER_CPU(struct ppc64_tlb_batch, ppc64_tlb_batch); > > extern void __flush_tlb_pending(struct ppc64_tlb_batch *batch); > > -#define __HAVE_ARCH_ENTER_LAZY_MMU_MODE > - > static inline void arch_enter_lazy_mmu_mode(void) > { > struct ppc64_tlb_batch *batch; > diff --git a/arch/powerpc/platforms/Kconfig.cputype b/arch/powerpc/platforms/Kconfig.cputype > index 7b527d18aa5e..2942d57cf59c 100644 > --- a/arch/powerpc/platforms/Kconfig.cputype > +++ b/arch/powerpc/platforms/Kconfig.cputype > @@ -93,6 +93,7 @@ config PPC_BOOK3S_64 > select IRQ_WORK > select PPC_64S_HASH_MMU if !PPC_RADIX_MMU > select KASAN_VMALLOC if KASAN > + select ARCH_HAS_LAZY_MMU_MODE > > config PPC_BOOK3E_64 > bool "Embedded processors" > diff --git a/arch/sparc/Kconfig b/arch/sparc/Kconfig > index a630d373e645..2bad14744ca4 100644 > --- a/arch/sparc/Kconfig > +++ b/arch/sparc/Kconfig > @@ -112,6 +112,7 @@ config SPARC64 > select NEED_PER_CPU_PAGE_FIRST_CHUNK > select ARCH_SUPPORTS_SCHED_SMT if SMP > select ARCH_SUPPORTS_SCHED_MC if SMP > + select ARCH_HAS_LAZY_MMU_MODE > > config ARCH_PROC_KCORE_TEXT > def_bool y > diff --git a/arch/sparc/include/asm/tlbflush_64.h b/arch/sparc/include/asm/tlbflush_64.h > index 925bb5d7a4e1..4e1036728e2f 100644 > --- a/arch/sparc/include/asm/tlbflush_64.h > +++ b/arch/sparc/include/asm/tlbflush_64.h > @@ -39,8 +39,6 @@ static inline void flush_tlb_range(struct vm_area_struct *vma, > > void flush_tlb_kernel_range(unsigned long start, unsigned long end); > > -#define __HAVE_ARCH_ENTER_LAZY_MMU_MODE > - > void flush_tlb_pending(void); > void arch_enter_lazy_mmu_mode(void); > void arch_flush_lazy_mmu_mode(void); > diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig > index fa3b616af03a..ef4332d720ab 100644 > --- a/arch/x86/Kconfig > +++ b/arch/x86/Kconfig > @@ -804,6 +804,7 @@ config PARAVIRT > config PARAVIRT_XXL > bool > depends on X86_64 > + select ARCH_HAS_LAZY_MMU_MODE > > config PARAVIRT_DEBUG > bool "paravirt-ops debugging" > diff --git a/arch/x86/boot/compressed/misc.h b/arch/x86/boot/compressed/misc.h > index db1048621ea2..cdd7f692d9ee 100644 > --- a/arch/x86/boot/compressed/misc.h > +++ b/arch/x86/boot/compressed/misc.h > @@ -11,6 +11,7 @@ > #undef CONFIG_PARAVIRT > #undef CONFIG_PARAVIRT_XXL > #undef CONFIG_PARAVIRT_SPINLOCKS > +#undef CONFIG_ARCH_HAS_LAZY_MMU_MODE > #undef CONFIG_KASAN > #undef CONFIG_KASAN_GENERIC > > diff --git a/arch/x86/boot/startup/sme.c b/arch/x86/boot/startup/sme.c > index e7ea65f3f1d6..b76a7c95dfe1 100644 > --- a/arch/x86/boot/startup/sme.c > +++ b/arch/x86/boot/startup/sme.c > @@ -24,6 +24,7 @@ > #undef CONFIG_PARAVIRT > #undef CONFIG_PARAVIRT_XXL > #undef CONFIG_PARAVIRT_SPINLOCKS > +#undef CONFIG_ARCH_HAS_LAZY_MMU_MODE > > /* > * This code runs before CPU feature bits are set. By default, the > diff --git a/arch/x86/include/asm/paravirt.h b/arch/x86/include/asm/paravirt.h > index b5e59a7ba0d0..13f9cd31c8f8 100644 > --- a/arch/x86/include/asm/paravirt.h > +++ b/arch/x86/include/asm/paravirt.h > @@ -526,7 +526,6 @@ static inline void arch_end_context_switch(struct task_struct *next) > PVOP_VCALL1(cpu.end_context_switch, next); > } > > -#define __HAVE_ARCH_ENTER_LAZY_MMU_MODE > static inline void arch_enter_lazy_mmu_mode(void) > { > PVOP_VCALL0(mmu.lazy_mode.enter); > diff --git a/include/linux/pgtable.h b/include/linux/pgtable.h > index 32e8457ad535..9894366e768b 100644 > --- a/include/linux/pgtable.h > +++ b/include/linux/pgtable.h > @@ -231,7 +231,7 @@ static inline int pmd_dirty(pmd_t pmd) > * held, but for kernel PTE updates, no lock is held). Nesting is not permitted > * and the mode cannot be used in interrupt context. > */ > -#ifndef __HAVE_ARCH_ENTER_LAZY_MMU_MODE > +#ifndef CONFIG_ARCH_HAS_LAZY_MMU_MODE > static inline void arch_enter_lazy_mmu_mode(void) {} > static inline void arch_leave_lazy_mmu_mode(void) {} > static inline void arch_flush_lazy_mmu_mode(void) {} > diff --git a/mm/Kconfig b/mm/Kconfig > index 0e26f4fc8717..5480c9a1bfb2 100644 > --- a/mm/Kconfig > +++ b/mm/Kconfig > @@ -1372,6 +1372,9 @@ config PT_RECLAIM > config FIND_NORMAL_PAGE > def_bool n > > +config ARCH_HAS_LAZY_MMU_MODE > + bool > + > source "mm/damon/Kconfig" > > endmenu