Messages in this thread | | | Subject | Re: [PATCH] staging: gasket: Convert get_user_pages*() --> pin_user_pages*() | From | John Hubbard <> | Date | Fri, 29 May 2020 00:38:20 -0700 |
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On 2020-05-28 23:27, Souptick Joarder wrote: > On Fri, May 29, 2020 at 11:46 AM Souptick Joarder <jrdr.linux@gmail.com> wrote: >> >> On Thu, May 28, 2020 at 4:34 PM Dan Carpenter <dan.carpenter@oracle.com> wrote: >>> >>> On Thu, May 28, 2020 at 02:32:42AM +0530, Souptick Joarder wrote: >>>> This code was using get_user_pages_fast(), in a "Case 2" scenario >>>> (DMA/RDMA), using the categorization from [1]. That means that it's >>>> time to convert the get_user_pages_fast() + put_page() calls to >>>> pin_user_pages_fast() + unpin_user_page() calls. >>> >>> You are saying that the page is used for DIO and not DMA, but it sure >>> looks to me like it is used for DMA. >> >> No, I was referring to "Case 2" scenario in change log which means it is >> used for DMA, not DIO.
Hi,
Dan, I also uncertain as to how you read this as referring to DIO. Case 2 is DMA or RDMA, and in fact the proposed commit log says both of those things: Case 2 and DMA/RDMA. I don't see "DIO" anywhere here...
>> >>> >>> 503 /* Map the page into DMA space. */ >>> 504 ptes[i].dma_addr = >>> 505 dma_map_page(pg_tbl->device, page, 0, PAGE_SIZE, >>> 506 DMA_BIDIRECTIONAL); >>> >>> To be honest, that starting paragraph was confusing. At first I thought >>> you were saying gasket was an RDMA driver. :P I shouldn't have to read >>> a different document to understand the commit message. It should be >>> summarized enough and the other documentation is supplemental. >>> >>> "In 2019 we introduced pin_user_pages() and now we are converting >>> get_user_pages() to the new API as appropriate". >> >> As all other similar conversion have similar change logs, so I was trying >> to maintain the same. John might have a different opinion on this. > > For example, I was referring to few recent similar commits for change logs. > > http://lkml.kernel.org/r/20200519002124.2025955-5-jhubbard@nvidia.com > https://lore.kernel.org/r/20200518015237.1568940-1-jhubbard@nvidia.com > > >> >> John, Any further opinion ??
Well, I've gotten away with the current wording for quite a few patches so far, but that sure doesn't mean it's perfect! :)
Maybe adding the words that Dan suggests, above, will suffice? Here:
>>> "In 2019 we introduced pin_user_pages() and now we are converting >>> get_user_pages() to the new API as appropriate".
thanks, -- John Hubbard NVIDIA
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