From patchwork Thu Sep 24 13:58:46 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christoph Hellwig X-Patchwork-Id: 11797549 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 8DEE6139A for ; Thu, 24 Sep 2020 13:59:40 +0000 (UTC) Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 5D19320888 for ; Thu, 24 Sep 2020 13:59:40 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="TvZtpxPO" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 5D19320888 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=lst.de Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=xen-devel-bounces@lists.xenproject.org Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1kLRmH-0000rp-NC; Thu, 24 Sep 2020 13:59:17 +0000 Received: from us1-rack-iad1.inumbo.com ([172.99.69.81]) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1kLRmF-0000ri-Da for xen-devel@lists.xenproject.org; Thu, 24 Sep 2020 13:59:15 +0000 X-Inumbo-ID: 2de92c1f-38d0-4c63-ab23-a81f9fcc8f19 Received: from casper.infradead.org (unknown [2001:8b0:10b:1236::1]) by us1-rack-iad1.inumbo.com (Halon) with ESMTPS id 2de92c1f-38d0-4c63-ab23-a81f9fcc8f19; Thu, 24 Sep 2020 13:59:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=Content-Transfer-Encoding:MIME-Version: References:In-Reply-To:Message-Id:Date:Subject:Cc:To:From:Sender:Reply-To: Content-Type:Content-ID:Content-Description; bh=UWYn4Nj1UDYUydETnuqo3HBArWRG9IThEGqk2ovW3VY=; b=TvZtpxPOZCFUh4PI7qnzVJeNGD bhPYLwAeN/vXPcxGQpRnhRk49qWu22f+ZFmvyyyxmDLbK6EfC3SA44P+coCfczuEdWylHw4x4g7h4 JTtyRHJPuvGq8DMzaeQ6qjal6a4KlnXT5PCHxCz+lkem/GJjTXQTjZ9Yf5NkiZFTFXZIKGJ1mTAoG eHJLyYtEgwHGsaswedTRA0CGz7/0iXCBLZyLsx8624XtfKmusp2n221qrAgtVtc4GrCZp1tmy5FfO CY57PLHtO0HMT5NghXvHOsoqfgmBBkenquNKp9xe9KQuDg+F2dG0hWvWf8ln/kEjNCia/Bk/7noAR GDN6H8EQ==; Received: from p4fdb0c34.dip0.t-ipconnect.de ([79.219.12.52] helo=localhost) by casper.infradead.org with esmtpsa (Exim 4.92.3 #3 (Red Hat Linux)) id 1kLRly-0003vJ-PO; Thu, 24 Sep 2020 13:58:59 +0000 From: Christoph Hellwig To: Andrew Morton Cc: Peter Zijlstra , Boris Ostrovsky , Juergen Gross , Stefano Stabellini , Jani Nikula , Joonas Lahtinen , Tvrtko Ursulin , Chris Wilson , Matthew Auld , Rodrigo Vivi , Minchan Kim , Matthew Wilcox , Nitin Gupta , x86@kernel.org, xen-devel@lists.xenproject.org, linux-kernel@vger.kernel.org, intel-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org, linux-mm@kvack.org Subject: [PATCH 04/11] mm: allow a NULL fn callback in apply_to_page_range Date: Thu, 24 Sep 2020 15:58:46 +0200 Message-Id: <20200924135853.875294-5-hch@lst.de> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20200924135853.875294-1-hch@lst.de> References: <20200924135853.875294-1-hch@lst.de> MIME-Version: 1.0 X-SRS-Rewrite: SMTP reverse-path rewritten from by casper.infradead.org. See http://www.infradead.org/rpr.html X-BeenThere: xen-devel@lists.xenproject.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Sender: "Xen-devel" Besides calling the callback on each page, apply_to_page_range also has the effect of pre-faulting all PTEs for the range. To support callers that only need the pre-faulting, make the callback optional. Based on a patch from Minchan Kim . Signed-off-by: Christoph Hellwig --- mm/memory.c | 16 +++++++++------- 1 file changed, 9 insertions(+), 7 deletions(-) diff --git a/mm/memory.c b/mm/memory.c index 469af373ae76e1..a60136046d7fcc 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -2231,13 +2231,15 @@ static int apply_to_pte_range(struct mm_struct *mm, pmd_t *pmd, arch_enter_lazy_mmu_mode(); - do { - if (create || !pte_none(*pte)) { - err = fn(pte++, addr, data); - if (err) - break; - } - } while (addr += PAGE_SIZE, addr != end); + if (fn) { + do { + if (create || !pte_none(*pte)) { + err = fn(pte++, addr, data); + if (err) + break; + } + } while (addr += PAGE_SIZE, addr != end); + } *mask |= PGTBL_PTE_MODIFIED; arch_leave_lazy_mmu_mode();