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From: John Hubbard <jhubbard@nvidia.com>
To: Christoph Hellwig <hch@lst.de>
Cc: "Andrew Morton" <akpm@linux-foundation.org>,
	"Al Viro" <viro@zeniv.linux.org.uk>,
	"Alex Williamson" <alex.williamson@redhat.com>,
	"Benjamin Herrenschmidt" <benh@kernel.crashing.org>,
	"Björn Töpel" <bjorn.topel@intel.com>,
	"Christoph Hellwig" <hch@infradead.org>,
	"Dan Williams" <dan.j.williams@intel.com>,
	"Daniel Vetter" <daniel@ffwll.ch>,
	"Dave Chinner" <david@fromorbit.com>,
	"David Airlie" <airlied@linux.ie>,
	"David S . Miller" <davem@davemloft.net>,
	"Ira Weiny" <ira.weiny@intel.com>, "Jan Kara" <jack@suse.cz>,
	"Jason Gunthorpe" <jgg@ziepe.ca>, "Jens Axboe" <axboe@kernel.dk>,
	"Jonathan Corbet" <corbet@lwn.net>,
	"Jérôme Glisse" <jglisse@redhat.com>,
	"Magnus Karlsson" <magnus.karlsson@intel.com>,
	"Mauro Carvalho Chehab" <mchehab@kernel.org>,
	"Michael Ellerman" <mpe@ellerman.id.au>,
	"Michal Hocko" <mhocko@suse.com>,
	"Mike Kravetz" <mike.kravetz@oracle.com>,
	"Paul Mackerras" <paulus@samba.org>,
	"Shuah Khan" <shuah@kernel.org>,
	"Vlastimil Babka" <vbabka@suse.cz>,
	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 <linux-kernel@vger.kernel.org>,
	"Aneesh Kumar K . V" <aneesh.kumar@linux.ibm.com>
Subject: Re: [PATCH v7 02/24] mm/gup: factor out duplicate code from four routines
Date: Thu, 21 Nov 2019 00:29:59 -0800
Message-ID: <852f6c27-8b65-547b-89e0-e8f32a4d17b9@nvidia.com> (raw)
In-Reply-To: <20191121080356.GA24784@lst.de>

On 11/21/19 12:03 AM, Christoph Hellwig wrote:
> On Wed, Nov 20, 2019 at 11:13:32PM -0800, John Hubbard wrote:
>> There are four locations in gup.c that have a fair amount of code
>> duplication. This means that changing one requires making the same
>> changes in four places, not to mention reading the same code four
>> times, and wondering if there are subtle differences.
>>
>> Factor out the common code into static functions, thus reducing the
>> overall line count and the code's complexity.
>>
>> Also, take the opportunity to slightly improve the efficiency of the
>> error cases, by doing a mass subtraction of the refcount, surrounded
>> by get_page()/put_page().
>>
>> Also, further simplify (slightly), by waiting until the the successful
>> end of each routine, to increment *nr.
> 
> Any reason for the spurious underscore in the function name?

argghh, I just fixed that, but applied the fix to the wrong patch! So now
patch 17 ("mm/gup: track FOLL_PIN pages") is improperly renaming it, instead
of this patch naming it correctly in the first place. Will fix.

> 
> Otherwise this looks fine and might be a worthwhile cleanup to feed
> Andrew for 5.5 independent of the gut of the changes.
> 
> Reviewed-by: Christoph Hellwig <hch@lst.de>
> 

Thanks for the reviews! Say, it sounds like your view here is that this
series should be targeted at 5.6 (not 5.5), is that what you have in mind?
And get the preparatory patches (1-9, and maybe even 10-16) into 5.5?

thanks,
-- 
John Hubbard
NVIDIA

  reply index

Thread overview: 55+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-11-21  7:13 [PATCH v7 00/24] mm/gup: track dma-pinned pages: FOLL_PIN John Hubbard
2019-11-21  7:13 ` [PATCH v7 01/24] mm/gup: pass flags arg to __gup_device_* functions John Hubbard
2019-11-21  8:06   ` Christoph Hellwig
2019-11-21  8:25     ` John Hubbard
2019-11-21  7:13 ` [PATCH v7 02/24] mm/gup: factor out duplicate code from four routines John Hubbard
2019-11-21  8:03   ` Christoph Hellwig
2019-11-21  8:29     ` John Hubbard [this message]
2019-11-21  9:49       ` Jan Kara
2019-11-21 21:47         ` John Hubbard
2019-11-21  9:54       ` Jan Kara
2019-11-22  2:54         ` John Hubbard
2019-11-22 11:15           ` Jan Kara
2019-11-21  7:13 ` [PATCH v7 03/24] mm/gup: move try_get_compound_head() to top, fix minor issues John Hubbard
2019-11-21  8:07   ` Christoph Hellwig
2019-11-21  7:13 ` [PATCH v7 04/24] mm: Cleanup __put_devmap_managed_page() vs ->page_free() John Hubbard
2019-11-21  8:04   ` Christoph Hellwig
2019-11-21  7:13 ` [PATCH v7 05/24] mm: devmap: refactor 1-based refcounting for ZONE_DEVICE pages John Hubbard
2019-11-21  8:05   ` Christoph Hellwig
2019-11-21  8:54     ` John Hubbard
2019-11-21 16:59       ` Dan Williams
2019-11-21 22:22         ` John Hubbard
2019-11-21  7:13 ` [PATCH v7 06/24] goldish_pipe: rename local pin_user_pages() routine John Hubbard
2019-11-21  8:08   ` Christoph Hellwig
2019-11-21  8:36     ` John Hubbard
2019-11-21  7:13 ` [PATCH v7 07/24] IB/umem: use get_user_pages_fast() to pin DMA pages John Hubbard
2019-11-21  8:07   ` Christoph Hellwig
2019-11-21 14:36     ` Jason Gunthorpe
2019-11-24  6:14       ` John Hubbard
2019-11-24 10:07       ` Leon Romanovsky
2019-11-25  0:05         ` John Hubbard
2019-11-25  0:53           ` Jason Gunthorpe
2019-11-21  7:13 ` [PATCH v7 08/24] media/v4l2-core: set pages dirty upon releasing DMA buffers John Hubbard
2019-11-21  8:09   ` Christoph Hellwig
2019-11-21  7:13 ` [PATCH v7 09/24] vfio, mm: fix get_user_pages_remote() and FOLL_LONGTERM John Hubbard
2019-11-21  8:10   ` Christoph Hellwig
2019-11-21  8:48     ` John Hubbard
2019-11-21 21:35   ` Alex Williamson
2019-11-21 21:49     ` John Hubbard
2019-11-21  7:13 ` [PATCH v7 10/24] mm/gup: introduce pin_user_pages*() and FOLL_PIN John Hubbard
2019-11-21  7:13 ` [PATCH v7 11/24] goldish_pipe: convert to pin_user_pages() and put_user_page() John Hubbard
2019-11-21  7:13 ` [PATCH v7 12/24] IB/{core,hw,umem}: set FOLL_PIN via pin_user_pages*(), fix up ODP John Hubbard
2019-11-21  7:13 ` [PATCH v7 13/24] mm/process_vm_access: set FOLL_PIN via pin_user_pages_remote() John Hubbard
2019-11-21  7:13 ` [PATCH v7 14/24] drm/via: set FOLL_PIN via pin_user_pages_fast() John Hubbard
2019-11-21  7:13 ` [PATCH v7 15/24] fs/io_uring: set FOLL_PIN via pin_user_pages() John Hubbard
2019-11-21  7:13 ` [PATCH v7 16/24] net/xdp: " John Hubbard
2019-11-21  7:13 ` [PATCH v7 17/24] mm/gup: track FOLL_PIN pages John Hubbard
2019-11-21  9:39   ` Jan Kara
2019-11-30 18:59   ` kbuild test robot
2019-11-21  7:13 ` [PATCH v7 18/24] media/v4l2-core: pin_user_pages (FOLL_PIN) and put_user_page() conversion John Hubbard
2019-11-21  7:13 ` [PATCH v7 19/24] vfio, mm: " John Hubbard
2019-11-21  7:13 ` [PATCH v7 20/24] powerpc: book3s64: convert to pin_user_pages() and put_user_page() John Hubbard
2019-11-21  7:13 ` [PATCH v7 21/24] mm/gup_benchmark: use proper FOLL_WRITE flags instead of hard-coding "1" John Hubbard
2019-11-21  7:13 ` [PATCH v7 22/24] mm/gup_benchmark: support pin_user_pages() and related calls John Hubbard
2019-11-21  7:13 ` [PATCH v7 23/24] selftests/vm: run_vmtests: invoke gup_benchmark with basic FOLL_PIN coverage John Hubbard
2019-11-21  7:13 ` [PATCH v7 24/24] mm, tree-wide: rename put_user_page*() to unpin_user_page*() John Hubbard

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