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]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8442EC3600C for ; Thu, 3 Apr 2025 20:46:53 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id C8DBE280006; Thu, 3 Apr 2025 16:46:51 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id C64D5280001; Thu, 3 Apr 2025 16:46:51 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id B2BB9280006; Thu, 3 Apr 2025 16:46:51 -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 97A25280001 for ; Thu, 3 Apr 2025 16:46:51 -0400 (EDT) Received: from smtpin01.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay08.hostedemail.com (Postfix) with ESMTP id 649D51411F0 for ; Thu, 3 Apr 2025 20:46:52 +0000 (UTC) X-FDA: 83293916664.01.D29820F Received: from nyc.source.kernel.org (nyc.source.kernel.org [147.75.193.91]) by imf13.hostedemail.com (Postfix) with ESMTP id 0DFA52000B for ; Thu, 3 Apr 2025 20:46:50 +0000 (UTC) Authentication-Results: imf13.hostedemail.com; dkim=none; spf=pass (imf13.hostedemail.com: domain of cmarinas@kernel.org designates 147.75.193.91 as permitted sender) smtp.mailfrom=cmarinas@kernel.org; dmarc=fail reason="SPF not aligned (relaxed), No valid DKIM" header.from=arm.com (policy=none) ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1743713211; 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; bh=iepe52Rf+3tYFzTMzqzuimF3WTgoE75H145Hmb0tl0Q=; b=P1La9YBtNk1mmS7TS37RhRWw+7ImZ8DfT5OeLcj+asCAMRwZWljxn0NOidSQSRf7Bcs3ce Mpzby+miB75oL6pSHW1YL8AVBIQgIO1btzNRrx6Wza9AwUAsJcjIZWzOK/4BkkdLLNEhvY OUunL08iaYO4Bhdkkjge5n2Sl6HQt9o= ARC-Authentication-Results: i=1; imf13.hostedemail.com; dkim=none; spf=pass (imf13.hostedemail.com: domain of cmarinas@kernel.org designates 147.75.193.91 as permitted sender) smtp.mailfrom=cmarinas@kernel.org; dmarc=fail reason="SPF not aligned (relaxed), No valid DKIM" header.from=arm.com (policy=none) ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1743713211; a=rsa-sha256; cv=none; b=4TndnAAz7kM0/SARKYPg8IDZCDCke2Lfbh0W900o9SV5Lf/ffmhlcsYNZ+mfAhtPnoQ87E avC9sOKCtIDAtuWyHk9U1uiluT9OqRkumN/gg51v7bZblTzFuxSOx2Qmle3j/OS9/Xvd5s tZBkAJ3AfKAZ1hiaJn+pp1ue2y5LEZ0= Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by nyc.source.kernel.org (Postfix) with ESMTP id 8DE18A446DC; Thu, 3 Apr 2025 20:41:21 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id D979BC4CEE3; Thu, 3 Apr 2025 20:46:46 +0000 (UTC) Date: Thu, 3 Apr 2025 21:46:44 +0100 From: Catalin Marinas To: Ryan Roberts Cc: Will Deacon , Pasha Tatashin , Andrew Morton , Uladzislau Rezki , Christoph Hellwig , David Hildenbrand , "Matthew Wilcox (Oracle)" , Mark Rutland , Anshuman Khandual , Alexandre Ghiti , Kevin Brodsky , linux-arm-kernel@lists.infradead.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v3 06/11] arm64/mm: Hoist barriers out of set_ptes_anysz() loop Message-ID: References: <20250304150444.3788920-1-ryan.roberts@arm.com> <20250304150444.3788920-7-ryan.roberts@arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20250304150444.3788920-7-ryan.roberts@arm.com> X-Rspamd-Queue-Id: 0DFA52000B X-Rspam-User: X-Rspamd-Server: rspam02 X-Stat-Signature: w77yy74c4914mii57pzcnxmp4w3pcu44 X-HE-Tag: 1743713210-754954 X-HE-Meta: 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 1f+rJ5ZZ uCx1Es5TJHK83x2z0HytoCqqkD41t+gVxALhQUiIrV/eEVf+XkvNazFy+KcJko8MNUrToio8CjAE/tTmsNIyRpxYRd7+MEj4gu9JaFhqHVPsCyNLXvbwb5sz0sA== 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 Tue, Mar 04, 2025 at 03:04:36PM +0000, Ryan Roberts wrote: > set_ptes_anysz() previously called __set_pte() for each PTE in the > range, which would conditionally issue a DSB and ISB to make the new PTE > value immediately visible to the table walker if the new PTE was valid > and for kernel space. > > We can do better than this; let's hoist those barriers out of the loop > so that they are only issued once at the end of the loop. We then reduce > the cost by the number of PTEs in the range. > > Signed-off-by: Ryan Roberts > --- > arch/arm64/include/asm/pgtable.h | 16 +++++++++++----- > 1 file changed, 11 insertions(+), 5 deletions(-) > > diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h > index e255a36380dc..1898c3069c43 100644 > --- a/arch/arm64/include/asm/pgtable.h > +++ b/arch/arm64/include/asm/pgtable.h > @@ -317,13 +317,11 @@ static inline void __set_pte_nosync(pte_t *ptep, pte_t pte) > WRITE_ONCE(*ptep, pte); > } > > -static inline void __set_pte(pte_t *ptep, pte_t pte) > +static inline void __set_pte_complete(pte_t pte) > { > - __set_pte_nosync(ptep, pte); > - > /* > * Only if the new pte is valid and kernel, otherwise TLB maintenance > - * or update_mmu_cache() have the necessary barriers. > + * has the necessary barriers. Thanks for removing the stale comment. Reviewed-by: Catalin Marinas