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 Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id DB56DC4332F for ; Mon, 14 Nov 2022 08:30:23 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 8A46710E080; Mon, 14 Nov 2022 08:30:21 +0000 (UTC) Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by gabe.freedesktop.org (Postfix) with ESMTPS id 49ECB10E080; Mon, 14 Nov 2022 08:30:17 +0000 (UTC) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id AD71D60F0E; Mon, 14 Nov 2022 08:30:16 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id DC080C433C1; Mon, 14 Nov 2022 08:30:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1668414615; bh=M5Go57T18KU3kovwfaSoPQkXTIJ9pU/x8zoi9VefwW4=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=SdH1QQKcLZQv3AKSNRqZgc4tXzBdMXgXKDuK3MoPQQRFpIYn6+O1nQZvg7Lp1GOYn QE742J9xLRn5ra6lGaVDnYoZgTzRjS0XJQSharaM9uVu6TJ//f4uH4suR3r5UAk5PK EjsXAoDr8CJU0bttAruYJ+pnYM1kFvmZR3cBw8CkWNisnUsoXW1ZUF1QcRRiDm7Y3L oMXJbnHupIRPsjq+jbJhGZzXY9uFf9StdS9G4A+jFvbnURqB8ZwRSbqvO+FUa98HIw VRhvftCN3zogKZ7mhH3RYpIiQTD/5vXd1uPM6Tw59jiLpnVXiTCkuHHIHG2JgSWt2/ SIDKXJb6O8rcQ== Date: Mon, 14 Nov 2022 10:30:11 +0200 From: Leon Romanovsky To: David Hildenbrand Subject: Re: [PATCH RFC 10/19] RDMA/umem: remove FOLL_FORCE usage Message-ID: References: <20221107161740.144456-1-david@redhat.com> <20221107161740.144456-11-david@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20221107161740.144456-11-david@redhat.com> X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: dri-devel@lists.freedesktop.org, linux-mm@kvack.org, Nadav Amit , linux-kselftest@vger.kernel.org, Andrea Arcangeli , linux-samsung-soc@vger.kernel.org, linux-rdma@vger.kernel.org, Hugh Dickins , Matthew Wilcox , Jason Gunthorpe , linux-arm-kernel@lists.infradead.org, linux-media@vger.kernel.org, Arnd Bergmann , John Hubbard , etnaviv@lists.freedesktop.org, Peter Xu , Muchun Song , Vlastimil Babka , Greg Kroah-Hartman , Oded Gabbay , linux-kernel@vger.kernel.org, Andrew Morton , Linus Torvalds , Mike Kravetz Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" On Mon, Nov 07, 2022 at 05:17:31PM +0100, David Hildenbrand wrote: > GUP now supports reliable R/O long-term pinning in COW mappings, such > that we break COW early. MAP_SHARED VMAs only use the shared zeropage so > far in one corner case (DAXFS file with holes), which can be ignored > because GUP does not support long-term pinning in fsdax (see > check_vma_flags()). > > Consequently, FOLL_FORCE | FOLL_WRITE | FOLL_LONGTERM is no longer required > for reliable R/O long-term pinning: FOLL_LONGTERM is sufficient. So stop > using FOLL_FORCE, which is really only for debugger access. > > Cc: Jason Gunthorpe > Cc: Leon Romanovsky > Signed-off-by: David Hildenbrand > --- > drivers/infiniband/core/umem.c | 8 ++++---- > 1 file changed, 4 insertions(+), 4 deletions(-) Thanks, Tested-by: Leon Romanovsky # Over mlx4 and mlx5.