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Message-ID: <a344b3b0-a43f-47eb-b5e4-9d54cda62518@acm.org>
Date:   Sat, 28 Oct 2023 16:07:23 -0700
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Subject: Re: [PATCH RFC 1/2] RDMA/rxe: don't allow registering !PAGE_SIZE mr
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To:     Zhu Yanjun <yanjun.zhu@linux.dev>,
        Li Zhijian <lizhijian@fujitsu.com>, zyjzyj2000@gmail.com,
        jgg@ziepe.ca, leon@kernel.org, linux-rdma@vger.kernel.org
Cc:     linux-kernel@vger.kernel.org, rpearsonhpe@gmail.com,
        matsuda-daisuke@fujitsu.com
References: <20231027054154.2935054-1-lizhijian@fujitsu.com>
 <53c18b2a-c3b2-4936-b654-12cb5f914622@linux.dev>
 <adad4ee6-ceef-4e45-a13d-048a1377e86f@acm.org>
 <45c23e30-8405-470b-825c-e5166cd8a313@linux.dev>
From:   Bart Van Assche <bvanassche@acm.org>
In-Reply-To: <45c23e30-8405-470b-825c-e5166cd8a313@linux.dev>
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On 10/27/23 19:48, Zhu Yanjun wrote:
> In this case, ULP with folio will not work well with current RXE after 
> this commit is applied.

Why not? RDMA ULPs like the SRP initiator driver use ib_map_mr_sg(). The
latter function calls rxe_map_mr_sg() if the RXE driver is used. 
rxe_map_mr_sg() calls ib_sg_to_pages(). ib_sg_to_pages() translates
SG-entries that are larger than a virtual memory page into multiple
entries with size mr->page_size.

Thanks,

Bart.