From: Gal Pressman <galpress@amazon.com>
To: Leon Romanovsky <leon@kernel.org>
Cc: RDMA mailing list <linux-rdma@vger.kernel.org>
Subject: Re: ib_umem_get and DMA_API_DEBUG question
Date: Mon, 26 Aug 2019 17:39:19 +0300 [thread overview]
Message-ID: <dd49fea6-9d2f-3727-2409-afd4ce3e4bba@amazon.com> (raw)
In-Reply-To: <20190826142320.GD4584@mtr-leonro.mtl.com>
On 26/08/2019 17:23, Leon Romanovsky wrote:
> On Mon, Aug 26, 2019 at 05:05:12PM +0300, Gal Pressman wrote:
>> Hi all,
>>
>> Lately I've been seeing DMA-API call traces on our automated testing runs which
>> complain about overlapping mappings of the same cacheline [1].
>> The problem is (most likely) caused due to multiple calls to ibv_reg_mr with the
>> same address, which as a result DMA maps the same physical addresses more than 7
>> (ACTIVE_CACHELINE_MAX_OVERLAP) times.
>>
>> Is this considered a bad behavior by the test? Should this be caught by
>> ib_core/driver somehow?
>
> If I'm not mistaken here, but we (Mellanox) decided that it is a bug in
> DMA debug code.
Thanks a lot Leon, good to know that it's not just an EFA thing.
In case you remember, is it a bug in the sense that the trace is a false alarm
or is it a bug that could cause real issues?
Did you guys by any chance analyze what are the consequences of this?
next prev parent reply other threads:[~2019-08-26 14:39 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-08-26 14:05 ib_umem_get and DMA_API_DEBUG question Gal Pressman
2019-08-26 14:23 ` Leon Romanovsky
2019-08-26 14:39 ` Gal Pressman [this message]
2019-08-26 14:39 ` Jason Gunthorpe
2019-08-27 8:28 ` Gal Pressman
2019-08-27 12:00 ` Jason Gunthorpe
2019-08-27 12:53 ` Gal Pressman
2019-08-27 13:17 ` Jason Gunthorpe
2019-08-27 13:22 ` Gal Pressman
2019-08-27 13:37 ` Jason Gunthorpe
2019-08-27 13:53 ` Gal Pressman
2019-08-28 14:15 ` Jason Gunthorpe
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