From patchwork Sat May 16 01:04:24 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ralph Campbell X-Patchwork-Id: 208501 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.9 required=3.0 tests=DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 504F2C433E0 for ; Sat, 16 May 2020 01:05:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2E1512076A for ; Sat, 16 May 2020 01:05:19 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=nvidia.com header.i=@nvidia.com header.b="lrzPXkDm" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726553AbgEPBFS (ORCPT ); Fri, 15 May 2020 21:05:18 -0400 Received: from hqnvemgate25.nvidia.com ([216.228.121.64]:8222 "EHLO hqnvemgate25.nvidia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726198AbgEPBFS (ORCPT ); Fri, 15 May 2020 21:05:18 -0400 Received: from hqpgpgate101.nvidia.com (Not Verified[216.228.121.13]) by hqnvemgate25.nvidia.com (using TLS: TLSv1.2, DES-CBC3-SHA) id ; Fri, 15 May 2020 18:04:01 -0700 Received: from hqmail.nvidia.com ([172.20.161.6]) by hqpgpgate101.nvidia.com (PGP Universal service); Fri, 15 May 2020 18:05:18 -0700 X-PGP-Universal: processed; by hqpgpgate101.nvidia.com on Fri, 15 May 2020 18:05:18 -0700 Received: from HQMAIL111.nvidia.com (172.20.187.18) by HQMAIL105.nvidia.com (172.20.187.12) with Microsoft SMTP Server (TLS) id 15.0.1473.3; Sat, 16 May 2020 01:05:16 +0000 Received: from hqnvemgw03.nvidia.com (10.124.88.68) by HQMAIL111.nvidia.com (172.20.187.18) with Microsoft SMTP Server (TLS) id 15.0.1473.3 via Frontend Transport; Sat, 16 May 2020 01:05:16 +0000 Received: from rcampbell-dev.nvidia.com (Not Verified[10.110.48.66]) by hqnvemgw03.nvidia.com with Trustwave SEG (v7, 5, 8, 10121) id ; Fri, 15 May 2020 18:05:16 -0700 From: Ralph Campbell To: , , , CC: Jerome Glisse , John Hubbard , Christoph Hellwig , Jason Gunthorpe , "Andrew Morton" , Shuah Khan , "Ralph Campbell" Subject: [PATCH v2] mm/hmm/test: use xa_for_each_range instead of looping Date: Fri, 15 May 2020 18:04:24 -0700 Message-ID: <20200516010424.2013-1-rcampbell@nvidia.com> X-Mailer: git-send-email 2.20.1 MIME-Version: 1.0 X-NVConfidentiality: public DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nvidia.com; s=n1; t=1589591041; bh=7PcaR+TkSMajawj1BN/KhyGBRigaOiTCyx/xApoMQEE=; h=X-PGP-Universal:From:To:CC:Subject:Date:Message-ID:X-Mailer: MIME-Version:X-NVConfidentiality:Content-Transfer-Encoding: Content-Type; b=lrzPXkDm5Nc+RSeJ1NcHqmSBqCfGYKdfdZiHrVkAkh4EukEWOhthbjVAGuteN4Ehh KxTsEaXMgW0mKu2+j/MmNqmP4uLECGnoUbfDhxAMJ/mVcsYNg+4mqtudXigxhFdHKp WBdRZKoQE7UjxLlJSSI9LE5NX2sZoQDHZ247KJyS+UjJ3BwOn2eSe+Yu51xHqAfxZV H9LQmYizeKK1ltQ+UV3+GEYYb68xy3jabI9OSW3/9LUW5k6QVH58CCyFqnhyZJLyir YI7vz9aIkj4sh7dez1lcKlDcfDtNSMmmTYVmtWq6JrqnSoiWqzhDmGn4n4IuilyoWM JA2liVlTUtagA== Sender: linux-kselftest-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kselftest@vger.kernel.org The test driver uses an xa_array to store virtual to physical address translations for a simulated hardware device. The MMU notifier invalidation callback is used to keep the table consistent with the CPU page table and is frequently called only for a page or two. However, if the test process exits unexpectedly or is killed, the range can be [0..ULONG_MAX] in which case calling xa_erase() for every possible PFN results in CPU timeouts. Use xa_for_each_range() to efficiently erase entries in the range. Signed-off-by: Ralph Campbell --- This patch is based on Jason Gunthorpe's hmm tree and should be folded into the ("mm/hmm/test: add selftest driver for HMM") patch once this patch is reviewed, etc. v1 -> v2: Use xa_for_each_range() instead of special casing [0..ULONG_MAX]. lib/test_hmm.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/lib/test_hmm.c b/lib/test_hmm.c index 8b36c26b717b..5c1858e325ba 100644 --- a/lib/test_hmm.c +++ b/lib/test_hmm.c @@ -196,13 +196,15 @@ static void dmirror_do_update(struct dmirror *dmirror, unsigned long start, unsigned long end) { unsigned long pfn; + void *entry; /* * The XArray doesn't hold references to pages since it relies on * the mmu notifier to clear page pointers when they become stale. * Therefore, it is OK to just clear the entry. */ - for (pfn = start >> PAGE_SHIFT; pfn < (end >> PAGE_SHIFT); pfn++) + xa_for_each_range(&dmirror->pt, pfn, entry, start >> PAGE_SHIFT, + end >> PAGE_SHIFT) xa_erase(&dmirror->pt, pfn); }