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 E2020CA1015 for ; Fri, 5 Sep 2025 11:14:23 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 32F338E0018; Fri, 5 Sep 2025 07:14:23 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 2DE3D8E0006; Fri, 5 Sep 2025 07:14:23 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 1A6808E0018; Fri, 5 Sep 2025 07:14:23 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0011.hostedemail.com [216.40.44.11]) by kanga.kvack.org (Postfix) with ESMTP id 025FF8E0006 for ; Fri, 5 Sep 2025 07:14:22 -0400 (EDT) Received: from smtpin22.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay04.hostedemail.com (Postfix) with ESMTP id A58BB1A00E9 for ; Fri, 5 Sep 2025 11:14:22 +0000 (UTC) X-FDA: 83854937964.22.EED55E8 Received: from tor.source.kernel.org (tor.source.kernel.org [172.105.4.254]) by imf21.hostedemail.com (Postfix) with ESMTP id ABCCE1C0080 for ; Fri, 5 Sep 2025 11:14:05 +0000 (UTC) Authentication-Results: imf21.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=ihMD5Uip; spf=pass (imf21.hostedemail.com: domain of rppt@kernel.org designates 172.105.4.254 as permitted sender) smtp.mailfrom=rppt@kernel.org; dmarc=pass (policy=quarantine) header.from=kernel.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1757070845; 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: in-reply-to:in-reply-to:references:references:dkim-signature; bh=g/wt05ObpdxwaNVDkgazUTN9jzFwrbxwSbbI3oRgsSg=; b=C+FEu/NAlqKwBtsTiXr1hDbqnMRerDvTIfzIaFEQl8TTmNkEXY3wgyKAC0ypuKtAYYNTmS dJCdRnDUziIJR2aeoUPWfUX9bLtfO/IvspgDB9dejtmjTmmBPBSIQihTmmM5HMzk1DoXXJ YEsxDUs3QibHxasnx7dhaGSjPkJ+Zmo= ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1757070845; a=rsa-sha256; cv=none; b=vqY3afThXpUYiG+sImYuspjZ3Y8SlqeRMlEQZxsD1uq7wcALNsErGzzEhJwsf/dDDjXpMT Vfq6evit5DjscKP7IXbxoyYRjykvy13f82F+ZqOrdGpAzbioVmFZQahLs0rqwlJpuBPZZr wCx39d+g24gbux4cJhmeTa35R6igExo= ARC-Authentication-Results: i=1; imf21.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=ihMD5Uip; spf=pass (imf21.hostedemail.com: domain of rppt@kernel.org designates 172.105.4.254 as permitted sender) smtp.mailfrom=rppt@kernel.org; dmarc=pass (policy=quarantine) header.from=kernel.org Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by tor.source.kernel.org (Postfix) with ESMTP id D8DF860280; Fri, 5 Sep 2025 11:14:04 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 93F34C4CEF1; Fri, 5 Sep 2025 11:13:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1757070844; bh=kDpzhB/6Cz5cknkR7vg25nX23vQb619EzR6gJMWg0zE=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=ihMD5UipqP42+z3YN+MrXn99n6Ycd3YsueOx6CaMNo+hdxO5RgsqI0SQxPdExPL3V BxsONFBqcXHbav7x1SkdqIDD48PmtLWsgPm58G0QlMiay/oaIVskT0KF8NuPaK9VFd /7wzkSZr/Kf5WRucMN8/UCNMZojnjOtaAmAF95Bjf8RmpqIT1ej5HygOv9JaajJW8G 3sqfezMFb01ibM/+0hkAjFN8sRUuYHQxj5dBVnj+if/YJu29wWq859HwQBz6EYrcmA 3EU4AmTwTsfLSifdqQkLCIzFzeBG/3X8Ze/ePLiEQWW6Tfu9V10hDtY4xQjiB241cI b5217/1pBB0Eg== Date: Fri, 5 Sep 2025 14:13:50 +0300 From: Mike Rapoport To: Kevin Brodsky Cc: linux-mm@kvack.org, 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" , "H. Peter Anvin" , Ingo Molnar , Jann Horn , Juergen Gross , "Liam R. Howlett" , Lorenzo Stoakes , Madhavan Srinivasan , Michael Ellerman , Michal Hocko , 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: Re: [PATCH 7/7] mm: update lazy_mmu documentation Message-ID: References: <20250904125736.3918646-1-kevin.brodsky@arm.com> <20250904125736.3918646-8-kevin.brodsky@arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20250904125736.3918646-8-kevin.brodsky@arm.com> X-Rspamd-Server: rspam10 X-Rspamd-Queue-Id: ABCCE1C0080 X-Stat-Signature: sy9heqgtt6rt3g9sswodm4oue8yc483r X-Rspam-User: X-HE-Tag: 1757070845-403840 X-HE-Meta: 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 2/qN+H2r n6OUWyCiJFPsFgKzDs8APL0Sv6KRWfjkISA7sAvn9326UBfqH/hVhoUJkk91eo4dyut6Eofq/iWIcBh0lMV8ystc2kBJ8R+22vx98w9wGv2jJDf9ecuBhTeN+hiSwWHs7HWeCox+xFfIcSZfrhaaBoaurrJ03e1zmZJna3zDy5qApTxKuJw0x8HChjUkS9m2lNMoPL5af9IKXyvYmgmeLsUqzY6M4oEY0Fq+fUYfcGkoxbGm699sjJCWD5J6DDtH0ZcSlEAP+U0pnBR2gVdsNrYDBXJJv738OLUQMNde1ixnddHJuJAxNjzQw5tkKl87LiY+oGaE5uFBtDcc6tesbl9qshKCOb1le4EAhbh8gzNQ02lNnlLKTwClxa3o+H+HW2fba6Y4sgcfVKgHTAcOIjK0FnYtJtPB+2JAa 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 Thu, Sep 04, 2025 at 01:57:36PM +0100, Kevin Brodsky wrote: > We now support nested lazy_mmu sections on all architectures > implementing the API. Update the API comment accordingly. > > Signed-off-by: Kevin Brodsky Acked-by: Mike Rapoport (Microsoft) > --- > 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 > -- Sincerely yours, Mike.