From patchwork Wed May 13 21:45:07 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ralph Campbell X-Patchwork-Id: 11547317 X-Patchwork-Delegate: jgg@ziepe.ca 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 7D5B0618 for ; Wed, 13 May 2020 21:45:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3B3ED20659 for ; Wed, 13 May 2020 21:45:36 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=nvidia.com header.i=@nvidia.com header.b="PFMTomRM" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729439AbgEMVpf (ORCPT ); Wed, 13 May 2020 17:45:35 -0400 Received: from hqnvemgate26.nvidia.com ([216.228.121.65]:16462 "EHLO hqnvemgate26.nvidia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729196AbgEMVpf (ORCPT ); Wed, 13 May 2020 17:45:35 -0400 Received: from hqpgpgate101.nvidia.com (Not Verified[216.228.121.13]) by hqnvemgate26.nvidia.com (using TLS: TLSv1.2, DES-CBC3-SHA) id ; Wed, 13 May 2020 14:45:22 -0700 Received: from hqmail.nvidia.com ([172.20.161.6]) by hqpgpgate101.nvidia.com (PGP Universal service); Wed, 13 May 2020 14:45:34 -0700 X-PGP-Universal: processed; by hqpgpgate101.nvidia.com on Wed, 13 May 2020 14:45:34 -0700 Received: from HQMAIL105.nvidia.com (172.20.187.12) by HQMAIL105.nvidia.com (172.20.187.12) with Microsoft SMTP Server (TLS) id 15.0.1473.3; Wed, 13 May 2020 21:45:32 +0000 Received: from hqnvemgw03.nvidia.com (10.124.88.68) by HQMAIL105.nvidia.com (172.20.187.12) with Microsoft SMTP Server (TLS) id 15.0.1473.3 via Frontend Transport; Wed, 13 May 2020 21:45:32 +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 ; Wed, 13 May 2020 14:45:32 -0700 From: Ralph Campbell To: , , , CC: Jerome Glisse , John Hubbard , Christoph Hellwig , Jason Gunthorpe , "Andrew Morton" , Shuah Khan , "Ralph Campbell" Subject: [PATCH] mm/hmm/test: destroy xa_array instead of looping Date: Wed, 13 May 2020 14:45:07 -0700 Message-ID: <20200513214507.30592-1-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=1589406322; bh=mUTdF1AVMZd0iSCg3E8fEbaYihKH2WAzpFyYOhyV/OU=; h=X-PGP-Universal:From:To:CC:Subject:Date:Message-ID:X-Mailer: MIME-Version:X-NVConfidentiality:Content-Transfer-Encoding: Content-Type; b=PFMTomRMAVJQ+UmxKAlAwof1dFot0qpMAJ1vATc+rjN6uEFZzlhYJjSuMLTODsPgc K1PGvX4Bl+rKy4f/9/TuNUPRXrd8vGl4tU9aHkqJKDonNKUipJOOOgodwCMSd9YrMw 0krWiaadjXUzTUkp7oLKOHZCjMyG14aKfhQeB8UVeMwu87bAoRYJuiF7RseMI3/pjg b9UQxFVFq45A+LHLKLIOTboyOgW1OKpwRmzNoQx6GCVok9yNkgqS9kavltRa4ARTUv cqFpoLFZXI0zCycLGP/OhkT0QgR3adaoJhqku3WXCke7DZF2GZD3THkRh8Gtdqf+Cn tifp6KhgVPa1g== Sender: linux-rdma-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-rdma@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. Munmap() can result in a large range being invalidated but in that case, the xa_array is likely to contain entries that need to be invalidated. Check for [0..ULONG_MAX] explicitly and just destroy the whole table. 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. lib/test_hmm.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/lib/test_hmm.c b/lib/test_hmm.c index 8b36c26b717b..b89852ec3c29 100644 --- a/lib/test_hmm.c +++ b/lib/test_hmm.c @@ -201,7 +201,13 @@ static void dmirror_do_update(struct dmirror *dmirror, unsigned long start, * 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. + * However, if the entire address space is being invalidated, it + * takes too long to clear them one at a time so destroy the array. */ + if (start == 0 && end == ULONG_MAX) { + xa_destroy(&dmirror->pt); + return; + } for (pfn = start >> PAGE_SHIFT; pfn < (end >> PAGE_SHIFT); pfn++) xa_erase(&dmirror->pt, pfn); }