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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 2EB60C021A9 for ; Mon, 17 Feb 2025 14:22:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-ID:Date:Subject:Cc:To:From: Reply-To:Content-Type:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=8wUxreknr65ickLPMtCy28QDzN6KgfgyfF+zJLcXS8I=; b=wXD2m4pLPFHTsb5vZGi/dDi3EC RJY0WvVfFsGA12T+oRxyhfAYI4elLylSZAWtT0+T28Uljf2FX3A2r8LlWHJIg8a0VdiK5wXvFZI5e 1RQQiyF22lfgLTW1iQ/fJfMZhXVh2MHcwM0sxVFSuu9FRuNXD3+nb3MrZVoulq2IdbpwxtLpxS2S6 LZhnCUygVh0Oit9o1tXeCvGr1xo/f5/tfXnUcLoWZqlWNB0NT9OimkVwj9/CMDLM4pZTzHHDDuU15 OnNu39o+B03lqVKfddhjXwdfPhUAdNyd5vZsONb9gOu+OZ5Lyt1finpnv005GLt/g0DRJBxT1PmC9 6PTiU+/A==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98 #2 (Red Hat Linux)) id 1tk20w-00000004pfl-14X5; Mon, 17 Feb 2025 14:22:26 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.98 #2 (Red Hat Linux)) id 1tk1nX-00000004mPw-3mST for linux-arm-kernel@lists.infradead.org; Mon, 17 Feb 2025 14:08:37 +0000 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 CA4601E5E; Mon, 17 Feb 2025 06:08:54 -0800 (PST) Received: from e125769.cambridge.arm.com (e125769.cambridge.arm.com [10.1.196.27]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 5BF713F6A8; Mon, 17 Feb 2025 06:08:33 -0800 (PST) From: Ryan Roberts To: Catalin Marinas , Will Deacon , Pasha Tatashin , Andrew Morton , Uladzislau Rezki , Christoph Hellwig , David Hildenbrand , "Matthew Wilcox (Oracle)" , Mark Rutland , Anshuman Khandual , Alexandre Ghiti , Kevin Brodsky Cc: Ryan Roberts , linux-arm-kernel@lists.infradead.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: [PATCH v2 06/14] arm64/mm: Hoist barriers out of set_ptes_anysz() loop Date: Mon, 17 Feb 2025 14:07:58 +0000 Message-ID: <20250217140809.1702789-7-ryan.roberts@arm.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20250217140809.1702789-1-ryan.roberts@arm.com> References: <20250217140809.1702789-1-ryan.roberts@arm.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20250217_060835_990507_522334DB X-CRM114-Status: GOOD ( 11.36 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org 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 | 14 ++++++++++---- 1 file changed, 10 insertions(+), 4 deletions(-) diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h index e255a36380dc..e4b1946b261f 100644 --- a/arch/arm64/include/asm/pgtable.h +++ b/arch/arm64/include/asm/pgtable.h @@ -317,10 +317,8 @@ 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. @@ -331,6 +329,12 @@ static inline void __set_pte(pte_t *ptep, pte_t pte) } } +static inline void __set_pte(pte_t *ptep, pte_t pte) +{ + __set_pte_nosync(ptep, pte); + __set_pte_complete(pte); +} + static inline pte_t __ptep_get(pte_t *ptep) { return READ_ONCE(*ptep); @@ -647,12 +651,14 @@ static inline void set_ptes_anysz(struct mm_struct *mm, pte_t *ptep, pte_t pte, for (;;) { __check_safe_pte_update(mm, ptep, pte); - __set_pte(ptep, pte); + __set_pte_nosync(ptep, pte); if (--nr == 0) break; ptep++; pte = pte_advance_pfn(pte, stride); } + + __set_pte_complete(pte); } static inline void __set_ptes(struct mm_struct *mm, -- 2.43.0