From: Jan Kara <jack@suse.cz>
To: Michal Hocko <mhocko@kernel.org>
Cc: john.hubbard@gmail.com,
"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>,
"Jérôme 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>
Subject: Re: [PATCH 00/34] put_user_pages(): miscellaneous call sites
Date: Fri, 2 Aug 2019 14:41:46 +0200 [thread overview]
Message-ID: <20190802124146.GL25064@quack2.suse.cz> (raw)
In-Reply-To: <20190802091244.GD6461@dhcp22.suse.cz>
On Fri 02-08-19 11:12:44, Michal Hocko wrote:
> On Thu 01-08-19 19:19:31, john.hubbard@gmail.com wrote:
> [...]
> > 2) Convert all of the call sites for get_user_pages*(), to
> > invoke put_user_page*(), instead of put_page(). This involves dozens of
> > call sites, and will take some time.
>
> How do we make sure this is the case and it will remain the case in the
> future? There must be some automagic to enforce/check that. It is simply
> not manageable to do it every now and then because then 3) will simply
> be never safe.
>
> Have you considered coccinele or some other scripted way to do the
> transition? I have no idea how to deal with future changes that would
> break the balance though.
Yeah, that's why I've been suggesting at LSF/MM that we may need to create
a gup wrapper - say vaddr_pin_pages() - and track which sites dropping
references got converted by using this wrapper instead of gup. The
counterpart would then be more logically named as unpin_page() or whatever
instead of put_user_page(). Sure this is not completely foolproof (you can
create new callsite using vaddr_pin_pages() and then just drop refs using
put_page()) but I suppose it would be a high enough barrier for missed
conversions... Thoughts?
Honza
--
Jan Kara <jack@suse.com>
SUSE Labs, CR
next prev parent reply other threads:[~2019-08-02 12:41 UTC|newest]
Thread overview: 68+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-08-02 2:19 [PATCH 00/34] put_user_pages(): miscellaneous call sites john.hubbard
2019-08-02 2:19 ` [PATCH 01/34] mm/gup: add make_dirty arg to put_user_pages_dirty_lock() john.hubbard
2019-08-02 2:19 ` [PATCH 02/34] net/rds: convert put_page() to put_user_page*() john.hubbard
2019-08-02 2:19 ` [PATCH 03/34] net/ceph: " john.hubbard
2019-08-02 22:32 ` Jeff Layton
2019-08-02 2:19 ` [PATCH 04/34] x86/kvm: " john.hubbard
2019-08-02 2:19 ` [PATCH 05/34] drm/etnaviv: convert release_pages() to put_user_pages() john.hubbard
2019-08-02 2:19 ` [PATCH 06/34] drm/i915: convert put_page() to put_user_page*() john.hubbard
2019-08-02 9:19 ` Joonas Lahtinen
2019-08-02 18:48 ` John Hubbard
2019-08-03 20:03 ` John Hubbard
2019-08-02 2:19 ` [PATCH 07/34] drm/radeon: " john.hubbard
2019-08-02 2:19 ` [PATCH 08/34] media/ivtv: " john.hubbard
2019-08-02 2:19 ` [PATCH 09/34] media/v4l2-core/mm: " john.hubbard
2019-08-02 2:19 ` [PATCH 10/34] genwqe: " john.hubbard
2019-08-03 7:06 ` Greg Kroah-Hartman
2019-08-02 2:19 ` [PATCH 11/34] scif: " john.hubbard
2019-08-02 2:19 ` [PATCH 12/34] vmci: " john.hubbard
2019-08-02 2:19 ` [PATCH 13/34] rapidio: " john.hubbard
2019-08-02 2:19 ` [PATCH 14/34] oradax: " john.hubbard
2019-08-02 2:19 ` [PATCH 15/34] staging/vc04_services: " john.hubbard
2019-08-03 7:06 ` Greg Kroah-Hartman
2019-08-02 2:19 ` [PATCH 16/34] drivers/tee: " john.hubbard
2019-08-02 6:29 ` Jens Wiklander
2019-08-02 18:51 ` John Hubbard
2019-08-02 2:19 ` [PATCH 17/34] vfio: " john.hubbard
2019-08-02 2:19 ` [PATCH 18/34] fbdev/pvr2fb: " john.hubbard
2019-08-02 2:19 ` [PATCH 19/34] fsl_hypervisor: " john.hubbard
2019-08-02 2:19 ` [PATCH 20/34] xen: " john.hubbard
2019-08-02 4:36 ` Juergen Gross
2019-08-02 5:48 ` John Hubbard
2019-08-02 6:10 ` Juergen Gross
2019-08-02 16:09 ` Weiny, Ira
2019-08-02 19:25 ` John Hubbard
2019-08-02 2:19 ` [PATCH 21/34] fs/exec.c: " john.hubbard
2019-08-02 2:19 ` [PATCH 22/34] orangefs: " john.hubbard
2019-08-02 2:19 ` [PATCH 23/34] uprobes: " john.hubbard
2019-08-02 2:19 ` [PATCH 24/34] futex: " john.hubbard
2019-08-02 2:19 ` [PATCH 25/34] mm/frame_vector.c: " john.hubbard
2019-08-02 2:19 ` [PATCH 26/34] mm/gup_benchmark.c: " john.hubbard
2019-08-02 14:19 ` Keith Busch
2019-08-02 2:19 ` [PATCH 27/34] mm/memory.c: " john.hubbard
2019-08-02 2:19 ` [PATCH 28/34] mm/madvise.c: " john.hubbard
2019-08-02 2:20 ` [PATCH 29/34] mm/process_vm_access.c: " john.hubbard
2019-08-02 2:20 ` [PATCH 30/34] crypt: " john.hubbard
2019-08-02 2:20 ` [PATCH 31/34] nfs: " john.hubbard
2019-08-03 1:27 ` Calum Mackay
2019-08-03 1:41 ` John Hubbard
2019-08-04 23:28 ` Calum Mackay
2019-08-02 2:20 ` [PATCH 32/34] goldfish_pipe: " john.hubbard
2019-08-02 2:20 ` [PATCH 33/34] kernel/events/core.c: " john.hubbard
2019-08-02 2:20 ` [PATCH 34/34] fs/binfmt_elf: " john.hubbard
2019-08-02 9:12 ` [PATCH 00/34] put_user_pages(): miscellaneous call sites Michal Hocko
2019-08-02 12:41 ` Jan Kara [this message]
2019-08-02 14:24 ` Matthew Wilcox
2019-08-02 14:52 ` Jan Kara
2019-08-02 19:14 ` John Hubbard
2019-08-07 8:37 ` Jan Kara
2019-08-07 8:46 ` Michal Hocko
2019-08-08 2:36 ` Ira Weiny
2019-08-08 3:46 ` John Hubbard
2019-08-08 16:25 ` Weiny, Ira
2019-08-08 18:18 ` John Hubbard
2019-08-09 8:34 ` Jan Kara
-- strict thread matches above, loose matches on Subject: below --
2019-08-02 2:16 john.hubbard
2019-08-02 2:39 ` John Hubbard
2019-08-02 8:05 ` Peter Zijlstra
2019-08-02 19:33 ` John Hubbard
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