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=-7.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 9C9D7C433DF for ; Sun, 31 May 2020 21:27:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6854D206DA for ; Sun, 31 May 2020 21:27:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1590960473; bh=YAAWFYD5XygTBfF+VHwfzKtOXXrdDhcaULk0QIxc1nE=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=UnCCCw7cNBh6Lh3NHQaXTvvMpTe9cfQASynrCjmN8uCU6rjRja8ayKHf3Ml/E2++R WF96Kn1aywbGBW/dx7xbw8lqJB0mWSGMIX5HX053166E/exQzUenFDptaQukcjgY07 G508nYKfzIZk+nJpRmx7eMtdyYiQhtcJGbQeDdU0= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728449AbgEaV1w (ORCPT ); Sun, 31 May 2020 17:27:52 -0400 Received: from mail-pl1-f194.google.com ([209.85.214.194]:35920 "EHLO mail-pl1-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727000AbgEaV1w (ORCPT ); Sun, 31 May 2020 17:27:52 -0400 Received: by mail-pl1-f194.google.com with SMTP id bg4so3434805plb.3; Sun, 31 May 2020 14:27:51 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=hSOr62Pti0vEw1YzTDDTts/kxJMfS9EuWHitDhWO+T0=; b=NIJrmWaSA9wWYa888tSjzvI9B3GQWQggKavvU7A+eS63tE8gcNilt0LzE256qDluwc +VozLjULmYs8gREP0Cn1fB0nzeCUtHnsszAaSLpBQ00PmJfrPlklkXP3apya98uhixAG GupZMy9RS0uY2sjgPZy/L6pAv811sET+b2eVLr42eGmDIQGFZVsFZFsN+GbPChA/p51e 9l6CyKWv0x8Iui1S7cS/a2hHGoeFqjJEvccs3YS8Yfv4rhzek4c7yeKxNgQTRDF1qOkf nK3LMxd4pEBIQF1v302EbXCbpy/jKvDYEwwO49HqThUTVyKiX+RYAWoSiZtk6Lrmzal1 RO1A== X-Gm-Message-State: AOAM530SZdFHnH0kbTHlHg5ri1GtvnZNM6UBP6777G9K40uCvUZNHsPd cyOHUoxPVcVoPb7NXhrNvW8= X-Google-Smtp-Source: ABdhPJy2uOew4a9wWNqGNAMGAoog2/HwHEsbhyxDssTfKTnbTyqc50Bysae+22gLDC/88EjnhDP/Ag== X-Received: by 2002:a17:902:b484:: with SMTP id y4mr17813090plr.21.1590960471357; Sun, 31 May 2020 14:27:51 -0700 (PDT) Received: from localhost ([2601:647:5b00:1161:a4cc:eef9:fbc0:2781]) by smtp.gmail.com with ESMTPSA id q185sm12360634pfb.82.2020.05.31.14.27.50 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 31 May 2020 14:27:50 -0700 (PDT) Date: Sun, 31 May 2020 14:27:49 -0700 From: Moritz Fischer To: "Wu, Hao" Cc: John Hubbard , LKML , "Xu, Yilun" , Moritz Fischer , "linux-fpga@vger.kernel.org" Subject: Re: [PATCH v3] fpga: dfl: afu: convert get_user_pages() --> pin_user_pages() Message-ID: <20200531212749.GA7770@epycbox.lan> References: <20200525221754.433023-1-jhubbard@nvidia.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, May 27, 2020 at 12:10:21AM +0000, Wu, Hao wrote: > > -----Original Message----- > > From: John Hubbard > > Sent: Tuesday, May 26, 2020 6:18 AM > > To: LKML > > Cc: John Hubbard ; Xu, Yilun ; > > Wu, Hao ; Moritz Fischer ; linux- > > fpga@vger.kernel.org > > Subject: [PATCH v3] fpga: dfl: afu: convert get_user_pages() --> > > pin_user_pages() > > > > This code was using get_user_pages_fast(), in a "Case 2" scenario > > (DMA/RDMA), using the categorization from [1]. That means that it's > > time to convert the get_user_pages_fast() + put_page() calls to > > pin_user_pages_fast() + unpin_user_pages() calls. > > > > There is some helpful background in [2]: basically, this is a small > > part of fixing a long-standing disconnect between pinning pages, and > > file systems' use of those pages. > > > > [1] Documentation/core-api/pin_user_pages.rst > > > > [2] "Explicit pinning of user-space pages": > > https://lwn.net/Articles/807108/ > > > > Cc: Xu Yilun > > Cc: Wu Hao > > Cc: Moritz Fischer > > Cc: linux-fpga@vger.kernel.org > > Signed-off-by: John Hubbard > > --- > > > > Hi, > > > > This is the same logical change as in v2, but it is applied to > > char-misc-next, in order to avoid a merge problem with Souptick's > > commit c9d7e3da1f3c ("fpga: dfl: afu: Corrected error handling levels > > ") > > Thanks a lot! > > Acked-by: Wu Hao > > Thanks > Hao > > > > > thanks, > > John Hubbard > > NVIDIA > > > > > > drivers/fpga/dfl-afu-dma-region.c | 19 +++++-------------- > > 1 file changed, 5 insertions(+), 14 deletions(-) > > > > diff --git a/drivers/fpga/dfl-afu-dma-region.c b/drivers/fpga/dfl-afu-dma- > > region.c > > index 5942343a5d6e..0b817b722920 100644 > > --- a/drivers/fpga/dfl-afu-dma-region.c > > +++ b/drivers/fpga/dfl-afu-dma-region.c > > @@ -16,15 +16,6 @@ > > > > #include "dfl-afu.h" > > > > -static void put_all_pages(struct page **pages, int npages) > > -{ > > - int i; > > - > > - for (i = 0; i < npages; i++) > > - if (pages[i]) > > - put_page(pages[i]); > > -} > > - > > void afu_dma_region_init(struct dfl_feature_platform_data *pdata) > > { > > struct dfl_afu *afu = dfl_fpga_pdata_get_private(pdata); > > @@ -57,22 +48,22 @@ static int afu_dma_pin_pages(struct > > dfl_feature_platform_data *pdata, > > goto unlock_vm; > > } > > > > - pinned = get_user_pages_fast(region->user_addr, npages, > > FOLL_WRITE, > > + pinned = pin_user_pages_fast(region->user_addr, npages, > > FOLL_WRITE, > > region->pages); > > if (pinned < 0) { > > ret = pinned; > > goto free_pages; > > } else if (pinned != npages) { > > ret = -EFAULT; > > - goto put_pages; > > + goto unpin_pages; > > } > > > > dev_dbg(dev, "%d pages pinned\n", pinned); > > > > return 0; > > > > -put_pages: > > - put_all_pages(region->pages, pinned); > > +unpin_pages: > > + unpin_user_pages(region->pages, pinned); > > free_pages: > > kfree(region->pages); > > unlock_vm: > > @@ -94,7 +85,7 @@ static void afu_dma_unpin_pages(struct > > dfl_feature_platform_data *pdata, > > long npages = region->length >> PAGE_SHIFT; > > struct device *dev = &pdata->dev->dev; > > > > - put_all_pages(region->pages, npages); > > + unpin_user_pages(region->pages, npages); > > kfree(region->pages); > > account_locked_vm(current->mm, npages, false); > > > > -- > > 2.26.2 > Applied to for-next. Thanks, Moritz