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 X-Spam-Level: X-Spam-Status: No, score=-7.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS 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 CD535C169C4 for ; Tue, 29 Jan 2019 16:54:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 93DC620989 for ; Tue, 29 Jan 2019 16:54:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728670AbfA2Qyn (ORCPT ); Tue, 29 Jan 2019 11:54:43 -0500 Received: from mx1.redhat.com ([209.132.183.28]:37274 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728544AbfA2Qyl (ORCPT ); Tue, 29 Jan 2019 11:54:41 -0500 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id B1D3237E8E; Tue, 29 Jan 2019 16:54:40 +0000 (UTC) Received: from localhost.localdomain.com (ovpn-122-2.rdu2.redhat.com [10.10.122.2]) by smtp.corp.redhat.com (Postfix) with ESMTP id AC35D102BCEB; Tue, 29 Jan 2019 16:54:39 +0000 (UTC) From: jglisse@redhat.com To: linux-mm@kvack.org Cc: linux-kernel@vger.kernel.org, =?UTF-8?q?J=C3=A9r=C3=B4me=20Glisse?= , Andrew Morton , Ralph Campbell , John Hubbard Subject: [PATCH 02/10] mm/hmm: do not erase snapshot when a range is invalidated Date: Tue, 29 Jan 2019 11:54:20 -0500 Message-Id: <20190129165428.3931-3-jglisse@redhat.com> In-Reply-To: <20190129165428.3931-1-jglisse@redhat.com> References: <20190129165428.3931-1-jglisse@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.29]); Tue, 29 Jan 2019 16:54:40 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Jérôme Glisse Users of HMM might be using the snapshot information to do preparatory step like dma mapping pages to a device before checking for invalidation through hmm_vma_range_done() so do not erase that information and assume users will do the right thing. Signed-off-by: Jérôme Glisse Cc: Andrew Morton Cc: Ralph Campbell Cc: John Hubbard --- mm/hmm.c | 6 ------ 1 file changed, 6 deletions(-) diff --git a/mm/hmm.c b/mm/hmm.c index b9f384ea15e9..74d69812d6be 100644 --- a/mm/hmm.c +++ b/mm/hmm.c @@ -170,16 +170,10 @@ static int hmm_invalidate_range(struct hmm *hmm, bool device, spin_lock(&hmm->lock); list_for_each_entry(range, &hmm->ranges, list) { - unsigned long addr, idx, npages; - if (update->end < range->start || update->start >= range->end) continue; range->valid = false; - addr = max(update->start, range->start); - idx = (addr - range->start) >> PAGE_SHIFT; - npages = (min(range->end, update->end) - addr) >> PAGE_SHIFT; - memset(&range->pfns[idx], 0, sizeof(*range->pfns) * npages); } spin_unlock(&hmm->lock); -- 2.17.2