From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <linux-xfs-owner@vger.kernel.org>
Received: from merlin.infradead.org ([205.233.59.134]:59956 "EHLO
        merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org
        with ESMTP id S1731650AbfHBIHV (ORCPT
        <rfc822;linux-xfs@vger.kernel.org>); Fri, 2 Aug 2019 04:07:21 -0400
Date: Fri, 2 Aug 2019 10:05:54 +0200
From: Peter Zijlstra <peterz@infradead.org>
Subject: Re: [PATCH 00/34] put_user_pages(): miscellaneous call sites
Message-ID: <20190802080554.GD2332@hirez.programming.kicks-ass.net>
References: <20190802021653.4882-1-jhubbard@nvidia.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <20190802021653.4882-1-jhubbard@nvidia.com>
Sender: linux-xfs-owner@vger.kernel.org
List-ID: <linux-xfs.vger.kernel.org>
List-Id: xfs
To: john.hubbard@gmail.com
Cc: Andrew Morton <akpm@linux-foundation.org>, Christoph Hellwig <hch@infradead.org>, Dan Williams <dan.j.williams@intel.com>, Dave Chinner <david@fromorbit.com>, Dave Hansen <dave.hansen@linux.intel.com>, Ira Weiny <ira.weiny@intel.com>, Jan Kara <jack@suse.cz>, Jason Gunthorpe <jgg@ziepe.ca>, =?iso-8859-1?B?Suly9G1l?= Glisse <jglisse@redhat.com>, LKML <linux-kernel@vger.kernel.org>, amd-gfx@lists.freedesktop.org, ceph-devel@vger.kernel.org, devel@driverdev.osuosl.org, devel@lists.orangefs.org, dri-devel@lists.freedesktop.org, intel-gfx@lists.freedesktop.org, kvm@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-block@vger.kernel.org, linux-crypto@vger.kernel.org, linux-fbdev@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-media@vger.kernel.org, linux-mm@kvack.org, linux-nfs@vger.kernel.org, linux-rdma@vger.kernel.org, linux-rpi-kernel@lists.infradead.org, linux-xfs@vger.kernel.org, netdev@vger.kernel.org, rds-devel@oss.oracle.com, sparclinux@vger.kernel.org, x86@kernel.org, xen-devel@lists.xenproject.org, John Hubbard <jhubbard@nvidia.com>

On Thu, Aug 01, 2019 at 07:16:19PM -0700, john.hubbard@gmail.com wrote:

> This is part a tree-wide conversion, as described in commit fc1d8e7cca2d
> ("mm: introduce put_user_page*(), placeholder versions"). That commit
> has an extensive description of the problem and the planned steps to
> solve it, but the highlites are:

That is one horridly mangled Changelog there :-/ It looks like it's
partially duplicated.

Anyway; no objections to any of that, but I just wanted to mention that
there are other problems with long term pinning that haven't been
mentioned, notably they inhibit compaction.

A long time ago I proposed an interface to mark pages as pinned, such
that we could run compaction before we actually did the pinning.