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=-8.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=unavailable 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 E25DFC43141 for ; Mon, 18 Nov 2019 12:02:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C230120857 for ; Mon, 18 Nov 2019 12:02:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727364AbfKRMCN (ORCPT ); Mon, 18 Nov 2019 07:02:13 -0500 Received: from mx2.suse.de ([195.135.220.15]:37464 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726760AbfKRMBZ (ORCPT ); Mon, 18 Nov 2019 07:01:25 -0500 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id BB66FB02C; Mon, 18 Nov 2019 12:01:20 +0000 (UTC) Received: by quack2.suse.cz (Postfix, from userid 1000) id 7DE191E4B03; Mon, 18 Nov 2019 10:49:18 +0100 (CET) Date: Mon, 18 Nov 2019 10:49:18 +0100 From: Jan Kara To: John Hubbard Cc: Andrew Morton , Al Viro , Alex Williamson , Benjamin Herrenschmidt , =?iso-8859-1?Q?Bj=F6rn_T=F6pel?= , Christoph Hellwig , Dan Williams , Daniel Vetter , Dave Chinner , David Airlie , "David S . Miller" , Ira Weiny , Jan Kara , Jason Gunthorpe , Jens Axboe , Jonathan Corbet , =?iso-8859-1?B?Suly9G1l?= Glisse , Magnus Karlsson , Mauro Carvalho Chehab , Michael Ellerman , Michal Hocko , Mike Kravetz , Paul Mackerras , Shuah Khan , Vlastimil Babka , bpf@vger.kernel.org, dri-devel@lists.freedesktop.org, kvm@vger.kernel.org, linux-block@vger.kernel.org, linux-doc@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-media@vger.kernel.org, linux-rdma@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, netdev@vger.kernel.org, linux-mm@kvack.org, LKML , Jason Gunthorpe Subject: Re: [PATCH v5 07/24] IB/umem: use get_user_pages_fast() to pin DMA pages Message-ID: <20191118094918.GE17319@quack2.suse.cz> References: <20191115055340.1825745-1-jhubbard@nvidia.com> <20191115055340.1825745-8-jhubbard@nvidia.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20191115055340.1825745-8-jhubbard@nvidia.com> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-rdma-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-rdma@vger.kernel.org On Thu 14-11-19 21:53:23, John Hubbard wrote: > And get rid of the mmap_sem calls, as part of that. Note > that get_user_pages_fast() will, if necessary, fall back to > __gup_longterm_unlocked(), which takes the mmap_sem as needed. > > Reviewed-by: Jason Gunthorpe > Reviewed-by: Ira Weiny > Signed-off-by: John Hubbard Looks good to me. You can add: Reviewed-by: Jan Kara Honza > --- > drivers/infiniband/core/umem.c | 17 ++++++----------- > 1 file changed, 6 insertions(+), 11 deletions(-) > > diff --git a/drivers/infiniband/core/umem.c b/drivers/infiniband/core/umem.c > index 24244a2f68cc..3d664a2539eb 100644 > --- a/drivers/infiniband/core/umem.c > +++ b/drivers/infiniband/core/umem.c > @@ -271,16 +271,13 @@ struct ib_umem *ib_umem_get(struct ib_udata *udata, unsigned long addr, > sg = umem->sg_head.sgl; > > while (npages) { > - down_read(&mm->mmap_sem); > - ret = get_user_pages(cur_base, > - min_t(unsigned long, npages, > - PAGE_SIZE / sizeof (struct page *)), > - gup_flags | FOLL_LONGTERM, > - page_list, NULL); > - if (ret < 0) { > - up_read(&mm->mmap_sem); > + ret = get_user_pages_fast(cur_base, > + min_t(unsigned long, npages, > + PAGE_SIZE / > + sizeof(struct page *)), > + gup_flags | FOLL_LONGTERM, page_list); > + if (ret < 0) > goto umem_release; > - } > > cur_base += ret * PAGE_SIZE; > npages -= ret; > @@ -288,8 +285,6 @@ struct ib_umem *ib_umem_get(struct ib_udata *udata, unsigned long addr, > sg = ib_umem_add_sg_table(sg, page_list, ret, > dma_get_max_seg_size(context->device->dma_device), > &umem->sg_nents); > - > - up_read(&mm->mmap_sem); > } > > sg_mark_end(sg); > -- > 2.24.0 > -- Jan Kara SUSE Labs, CR