From: Artemy Kovalyov <artemyko@mellanox.com>
To: John Hubbard <jhubbard@nvidia.com>,
Ira Weiny <ira.weiny@intel.com>,
"john.hubbard@gmail.com" <john.hubbard@gmail.com>
Cc: "linux-mm@kvack.org" <linux-mm@kvack.org>,
Andrew Morton <akpm@linux-foundation.org>,
LKML <linux-kernel@vger.kernel.org>,
"Jason Gunthorpe" <jgg@ziepe.ca>,
Doug Ledford <dledford@redhat.com>,
"linux-rdma@vger.kernel.org" <linux-rdma@vger.kernel.org>
Subject: Re: [PATCH v2] RDMA/umem: minor bug fix and cleanup in error handling paths
Date: Wed, 6 Mar 2019 03:02:36 +0200 [thread overview]
Message-ID: <903383a6-f2c9-4a69-83c0-9be9c052d4be@mellanox.com> (raw)
In-Reply-To: <332021c5-ab72-d54f-85c8-b2b12b76daed@nvidia.com>
On 04/03/2019 00:37, John Hubbard wrote:
> On 3/3/19 1:52 AM, Artemy Kovalyov wrote:
>>
>>
>> On 02/03/2019 21:44, Ira Weiny wrote:
>>>
>>> On Sat, Mar 02, 2019 at 12:24:35PM -0800, john.hubbard@gmail.com wrote:
>>>> From: John Hubbard <jhubbard@nvidia.com>
>>>>
>>>> ...
>
> OK, thanks for explaining! Artemy, while you're here, any thoughts about the
> release_pages, and the change of the starting point, from the other part of the
> patch:
>
> @@ -684,9 +677,11 @@ int ib_umem_odp_map_dma_pages(struct ib_umem_odp *umem_odp,
> u64 user_virt,
> mutex_unlock(&umem_odp->umem_mutex);
>
> if (ret < 0) {
> - /* Release left over pages when handling errors. */
> - for (++j; j < npages; ++j)
release_pages() is an optimized batch put_page() so it's ok.
but! release starting from page next to one cause failure in
ib_umem_odp_map_dma_single_page() is correct because failure flow of
this functions already called put_page().
So release_pages(&local_page_list[j+1], npages - j-1) would be correct.
> - put_page(local_page_list[j]);
> + /*
> + * Release pages, starting at the the first page
> + * that experienced an error.
> + */
> + release_pages(&local_page_list[j], npages - j);
> break;
> }
> }
>
> ?
>
> thanks,
>
next prev parent reply other threads:[~2019-03-06 1:02 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-03-02 3:27 [PATCH 0/1] RDMA/umem: minor bug fix and cleanup in error handling paths john.hubbard
2019-03-02 3:27 ` [PATCH] " john.hubbard
2019-03-02 16:03 ` kbuild test robot
2019-03-02 16:14 ` kbuild test robot
2019-03-02 20:24 ` [PATCH v2] " john.hubbard
2019-03-02 19:44 ` Ira Weiny
2019-03-03 9:52 ` Artemy Kovalyov
2019-03-03 16:55 ` Ira Weiny
2019-03-04 23:11 ` John Hubbard
2019-03-04 20:13 ` Ira Weiny
2019-03-05 20:10 ` John Hubbard
2019-03-04 23:36 ` John Hubbard
2019-03-05 0:53 ` Jason Gunthorpe
2019-03-03 22:37 ` John Hubbard
2019-03-04 6:44 ` Leon Romanovsky
2019-03-06 1:02 ` Artemy Kovalyov [this message]
2019-03-06 1:32 ` Jason Gunthorpe
2019-03-06 1:34 ` John Hubbard
2019-03-06 1:37 ` John Hubbard
2019-03-06 1:51 ` Jason Gunthorpe
2019-03-06 2:04 ` John Hubbard
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