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From: Jason Gunthorpe <jgg@ziepe.ca>
To: Li Zhijian <lizhijian@fujitsu.com>
Cc: linux-rdma@vger.kernel.org, linux-kernel@vger.kernel.org,
	zyjzyj2000@gmail.com, leon@kernel.org,
	Yi Zhang <yi.zhang@redhat.com>
Subject: Re: [PATCH RFC] rxe: Fix iova-to-va conversion for MR page sizes != PAGE_SIZE
Date: Mon, 5 Jan 2026 21:01:59 -0400	[thread overview]
Message-ID: <20260106010159.GN125261@ziepe.ca> (raw)
In-Reply-To: <20251226095237.3047496-1-lizhijian@fujitsu.com>

On Fri, Dec 26, 2025 at 05:52:37PM +0800, Li Zhijian wrote:
> The current implementation incorrectly handles memory regions (MRs) with
> page sizes different from the system PAGE_SIZE. The core issue is that
> rxe_set_page() is called with mr->page_size step increments, but the
> page_list stores individual struct page pointers, each representing
> PAGE_SIZE of memory.
> 
> Problem scenarios with concrete examples:
> 
> 1. mr->page_size > PAGE_SIZE (e.g., 64K MR with 4K system pages):

Why does RXE even have mr->page_size at all?

Real HW has this value to optimize for large page sizes, but I'm not
sure we really need this for RXE..

Jason

      parent reply	other threads:[~2026-01-06  1:02 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-12-26  9:52 Li Zhijian
2025-12-27  5:24 ` Zhu Yanjun
2025-12-30  4:02   ` Zhu Yanjun
2025-12-30  4:47     ` Zhijian Li (Fujitsu)
2025-12-30  4:57       ` Zhu Yanjun
2026-01-05  6:55 ` Zhijian Li (Fujitsu)
2026-01-05  7:39   ` Zhijian Li (Fujitsu)
2026-01-06  1:07   ` Jason Gunthorpe
2026-01-07  3:02     ` Zhijian Li (Fujitsu)
2026-01-06  1:01 ` Jason Gunthorpe [this message]

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