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From: Tristan Madani <tristmd@gmail.com>
To: Zhu Yanjun <yanjun.zhu@linux.dev>
Cc: Zhu Yanjun <zyjzyj2000@gmail.com>, Jason Gunthorpe <jgg@ziepe.ca>,
	Leon Romanovsky <leon@kernel.org>,
	Moni Shoua <monis@mellanox.com>,
	linux-rdma@vger.kernel.org, stable@vger.kernel.org
Subject: Re: [PATCH 1/2] RDMA/rxe: copy send WQE to kernel buffer before processing
Date: Tue, 18 Aug 2026 13:33:19 +0000	[thread overview]
Message-ID: <20260818133319.4128416-1-tristmd@gmail.com> (raw)
In-Reply-To: <2063d67f-27c5-4329-aaf5-39823f9de6ff@linux.dev>

Hi Yanjun,

Thank you for the review.

Regarding concern 2: unless I am mistaken, rxe_sender() calls
rxe_requester() then rxe_completer() sequentially in the same
work item (rxe_req.c:836), and do_task() prevents re-entry, so
the requester and completer should not run concurrently on the
same QP. But please correct me if there is a scheduling path
I missed.

Either way, using WRITE_ONCE() for the state and status fields
instead of a bulk memcpy() is cleaner and eliminates any concern
about tearing from concurrent userspace writes (concern 1). I
will send v2 with targeted WRITE_ONCE() writebacks for just the
fields that need to be visible, dropping the bulk memcpy.

Best regards,
Tristan Madani

  reply	other threads:[~2026-08-18 13:33 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-08-16 10:44 [PATCH 1/2] RDMA/rxe: copy send WQE to kernel buffer before processing Tristan Madani
2026-08-16 10:44 ` [PATCH 2/2] RDMA/rxe: copy completer " Tristan Madani
2026-08-16 21:44 ` [PATCH 1/2] RDMA/rxe: copy send " Zhu Yanjun
2026-08-18 13:33   ` Tristan Madani [this message]
2026-08-19  6:28     ` Zhu Yanjun

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