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 54E99CA1002 for ; Thu, 4 Sep 2025 12:58:58 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id B26168E0019; Thu, 4 Sep 2025 08:58:57 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id AFD588E0013; Thu, 4 Sep 2025 08:58:57 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id A18848E0019; Thu, 4 Sep 2025 08:58:57 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0012.hostedemail.com [216.40.44.12]) by kanga.kvack.org (Postfix) with ESMTP id 8ECD18E0013 for ; Thu, 4 Sep 2025 08:58:57 -0400 (EDT) Received: from smtpin03.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay05.hostedemail.com (Postfix) with ESMTP id 58F8B56385 for ; Thu, 4 Sep 2025 12:58:57 +0000 (UTC) X-FDA: 83851572714.03.F68133B Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by imf01.hostedemail.com (Postfix) with ESMTP id C1AEA4000D for ; Thu, 4 Sep 2025 12:58:55 +0000 (UTC) Authentication-Results: imf01.hostedemail.com; dkim=none; spf=pass (imf01.hostedemail.com: domain of kevin.brodsky@arm.com designates 217.140.110.172 as permitted sender) smtp.mailfrom=kevin.brodsky@arm.com; dmarc=pass (policy=none) header.from=arm.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1756990735; 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-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=vLlXfKPxMlaUvMb/as1DeaEQrf2xWKKiAo/9OSQRFtg=; b=BUGUboriHUWUy/mgHMPaDAYPYj9Q4GQGGsSWM0Ne9QOaXoZl1roAZC+iJN3Cu+BxrlamN6 fxUwH1vRJFXG3mAvZt9BsyZMwMH1RDu4h3hL91i+yGvEKGm9HcvNj0ffqNCsmF9Wqfk09R S2pqVVE15AwIGCrOYRxPtSe9uSk1O0Q= ARC-Authentication-Results: i=1; imf01.hostedemail.com; dkim=none; spf=pass (imf01.hostedemail.com: domain of kevin.brodsky@arm.com designates 217.140.110.172 as permitted sender) smtp.mailfrom=kevin.brodsky@arm.com; dmarc=pass (policy=none) header.from=arm.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1756990735; a=rsa-sha256; cv=none; b=X38gjOfvPJDZ/ZhD+73CXW5VHJpDAJaesFlu6f5lJowCQbaJR8GZhgi4tLJrVajyKRQ02y Ncr8qPXCd8o9/Oyg9gtkhL36SOiwE2oJTTbyJCAPH0XFQdpB3kNTxTW2j5Du3j9dZ8W6dE S4oOh/TyqWyphs7LSUqRJJixiPFHtFM= 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 A725E2F28; Thu, 4 Sep 2025 05:58:46 -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 757883F6A8; Thu, 4 Sep 2025 05:58:50 -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 , linux-arm-kernel@lists.infradead.org, linuxppc-dev@lists.ozlabs.org, sparclinux@vger.kernel.org, xen-devel@lists.xenproject.org Subject: [PATCH 7/7] mm: update lazy_mmu documentation Date: Thu, 4 Sep 2025 13:57:36 +0100 Message-ID: <20250904125736.3918646-8-kevin.brodsky@arm.com> X-Mailer: git-send-email 2.47.0 In-Reply-To: <20250904125736.3918646-1-kevin.brodsky@arm.com> References: <20250904125736.3918646-1-kevin.brodsky@arm.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Rspamd-Server: rspam02 X-Rspamd-Queue-Id: C1AEA4000D X-Stat-Signature: o9u7jnbwz95tt8ckw153ir1buf6rctyg X-Rspam-User: X-HE-Tag: 1756990735-227346 X-HE-Meta: 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 O+JcDBJu JQY2Xl0jzuWeXUW/dKEbubdbGVlx3XmWiYX2i7YdExnY+w5VAuP92zl3EyzLclnyWvxVzPFsrVp9ZmnjBPbJoL8iGfuJuv8o5enA1p5VbcS4gQJLuRMNXdrEzx72KA1cxmCia7Z5u+NZS7KOFQ788JRt6WMgNFhrdAnJxdB0khczlb2t54P6PNnFxuLQJwaCFZP5lPbEOOFafbnjdisOxIpP1N/HX9ZMBHOoW7O6FQAo1+QA= 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: We now support nested lazy_mmu sections on all architectures implementing the API. Update the API comment accordingly. Signed-off-by: Kevin Brodsky --- include/linux/pgtable.h | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-) diff --git a/include/linux/pgtable.h b/include/linux/pgtable.h index 6932c8e344ab..be0f059beb4d 100644 --- a/include/linux/pgtable.h +++ b/include/linux/pgtable.h @@ -228,8 +228,18 @@ static inline int pmd_dirty(pmd_t pmd) * of the lazy mode. So the implementation must assume preemption may be enabled * and cpu migration is possible; it must take steps to be robust against this. * (In practice, for user PTE updates, the appropriate page table lock(s) are - * held, but for kernel PTE updates, no lock is held). Nesting is not permitted - * and the mode cannot be used in interrupt context. + * held, but for kernel PTE updates, no lock is held). The mode cannot be used + * in interrupt context. + * + * Calls may be nested: an arch_{enter,leave}_lazy_mmu_mode() pair may be called + * while the lazy MMU mode has already been enabled. An implementation should + * handle this using the state returned by enter() and taken by the matching + * leave() call; the LAZY_MMU_{DEFAULT,NESTED} flags can be used to indicate + * whether this enter/leave pair is nested inside another or not. (It is up to + * the implementation to track whether the lazy MMU mode is enabled at any point + * in time.) The expectation is that leave() will flush any batched state + * unconditionally, but only leave the lazy MMU mode if the passed state is not + * LAZY_MMU_NESTED. */ #ifndef __HAVE_ARCH_ENTER_LAZY_MMU_MODE typedef int lazy_mmu_state_t; -- 2.47.0