From patchwork Wed Jan 23 22:23:15 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Jerome Glisse X-Patchwork-Id: 10778019 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 445B91390 for ; Wed, 23 Jan 2019 22:24:02 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 343CF2C4F8 for ; Wed, 23 Jan 2019 22:24:02 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 289AD2C4FF; Wed, 23 Jan 2019 22:24:02 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id AE2602C4FE for ; Wed, 23 Jan 2019 22:24:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727388AbfAWWX4 (ORCPT ); Wed, 23 Jan 2019 17:23:56 -0500 Received: from mx1.redhat.com ([209.132.183.28]:54594 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727356AbfAWWXz (ORCPT ); Wed, 23 Jan 2019 17:23:55 -0500 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id D387F432A0; Wed, 23 Jan 2019 22:23:54 +0000 (UTC) Received: from localhost.localdomain.com (ovpn-120-127.rdu2.redhat.com [10.10.120.127]) by smtp.corp.redhat.com (Postfix) with ESMTP id 3606D6A685; Wed, 23 Jan 2019 22:23:52 +0000 (UTC) From: jglisse@redhat.com To: linux-mm@kvack.org Cc: Andrew Morton , linux-kernel@vger.kernel.org, =?utf-8?b?SsOpcsO0bWUgR2xpc3Nl?= , =?utf-8?q?Christian_?= =?utf-8?q?K=C3=B6nig?= , Jan Kara , Felix Kuehling , Jason Gunthorpe , Matthew Wilcox , Ross Zwisler , Dan Williams , Paolo Bonzini , =?utf-8?b?UmFkaW0gS3LEjW3DocWZ?= , Michal Hocko , Ralph Campbell , John Hubbard , kvm@vger.kernel.org, dri-devel@lists.freedesktop.org, linux-rdma@vger.kernel.org, linux-fsdevel@vger.kernel.org, Arnd Bergmann Subject: [PATCH v4 9/9] RDMA/umem_odp: optimize out the case when a range is updated to read only Date: Wed, 23 Jan 2019 17:23:15 -0500 Message-Id: <20190123222315.1122-10-jglisse@redhat.com> In-Reply-To: <20190123222315.1122-1-jglisse@redhat.com> References: <20190123222315.1122-1-jglisse@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.30]); Wed, 23 Jan 2019 22:23:55 +0000 (UTC) Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP From: Jérôme Glisse When range of virtual address is updated read only and corresponding user ptr object are already read only it is pointless to do anything. Optimize this case out. Signed-off-by: Jérôme Glisse Cc: Christian König Cc: Jan Kara Cc: Felix Kuehling Cc: Jason Gunthorpe Cc: Andrew Morton Cc: Matthew Wilcox Cc: Ross Zwisler Cc: Dan Williams Cc: Paolo Bonzini Cc: Radim Krčmář Cc: Michal Hocko Cc: Ralph Campbell Cc: John Hubbard Cc: kvm@vger.kernel.org Cc: dri-devel@lists.freedesktop.org Cc: linux-rdma@vger.kernel.org Cc: linux-fsdevel@vger.kernel.org Cc: Arnd Bergmann --- drivers/infiniband/core/umem_odp.c | 22 +++++++++++++++++++--- include/rdma/ib_umem_odp.h | 1 + 2 files changed, 20 insertions(+), 3 deletions(-) diff --git a/drivers/infiniband/core/umem_odp.c b/drivers/infiniband/core/umem_odp.c index a4ec43093cb3..fa4e7fdcabfc 100644 --- a/drivers/infiniband/core/umem_odp.c +++ b/drivers/infiniband/core/umem_odp.c @@ -140,8 +140,15 @@ static void ib_umem_notifier_release(struct mmu_notifier *mn, static int invalidate_range_start_trampoline(struct ib_umem_odp *item, u64 start, u64 end, void *cookie) { + bool update_to_read_only = *((bool *)cookie); + ib_umem_notifier_start_account(item); - item->umem.context->invalidate_range(item, start, end); + /* + * If it is already read only and we are updating to read only then we + * do not need to change anything. So save time and skip this one. + */ + if (!update_to_read_only || !item->read_only) + item->umem.context->invalidate_range(item, start, end); return 0; } @@ -150,6 +157,7 @@ static int ib_umem_notifier_invalidate_range_start(struct mmu_notifier *mn, { struct ib_ucontext_per_mm *per_mm = container_of(mn, struct ib_ucontext_per_mm, mn); + bool update_to_read_only; if (range->blockable) down_read(&per_mm->umem_rwsem); @@ -166,10 +174,13 @@ static int ib_umem_notifier_invalidate_range_start(struct mmu_notifier *mn, return 0; } + update_to_read_only = mmu_notifier_range_update_to_read_only(range); + return rbt_ib_umem_for_each_in_range(&per_mm->umem_tree, range->start, range->end, invalidate_range_start_trampoline, - range->blockable, NULL); + range->blockable, + &update_to_read_only); } static int invalidate_range_end_trampoline(struct ib_umem_odp *item, u64 start, @@ -363,6 +374,9 @@ struct ib_umem_odp *ib_alloc_odp_umem(struct ib_ucontext_per_mm *per_mm, goto out_odp_data; } + /* Assume read only at first, each time GUP is call this is updated. */ + odp_data->read_only = true; + odp_data->dma_list = vzalloc(array_size(pages, sizeof(*odp_data->dma_list))); if (!odp_data->dma_list) { @@ -619,8 +633,10 @@ int ib_umem_odp_map_dma_pages(struct ib_umem_odp *umem_odp, u64 user_virt, goto out_put_task; } - if (access_mask & ODP_WRITE_ALLOWED_BIT) + if (access_mask & ODP_WRITE_ALLOWED_BIT) { + umem_odp->read_only = false; flags |= FOLL_WRITE; + } start_idx = (user_virt - ib_umem_start(umem)) >> page_shift; k = start_idx; diff --git a/include/rdma/ib_umem_odp.h b/include/rdma/ib_umem_odp.h index 0b1446fe2fab..8256668c6170 100644 --- a/include/rdma/ib_umem_odp.h +++ b/include/rdma/ib_umem_odp.h @@ -76,6 +76,7 @@ struct ib_umem_odp { struct completion notifier_completion; int dying; struct work_struct work; + bool read_only; }; static inline struct ib_umem_odp *to_ib_umem_odp(struct ib_umem *umem)