linux-kernel - Re: [PATCH] RDMA/siw: Reuse value read using READ

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Message-ID: <20240310113306.GF12921@unreal>
Date: Sun, 10 Mar 2024 13:33:06 +0200
From: Leon Romanovsky <leon@...nel.org>
To: linke li <lilinke99@...com>
Cc: Bernard Metzler <bmt@...ich.ibm.com>, Jason Gunthorpe <jgg@...pe.ca>,
	linux-rdma@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH] RDMA/siw: Reuse value read using READ_ONCE instead of
 re-reading it

On Sat, Mar 09, 2024 at 08:27:16PM +0800, linke li wrote:
> In siw_orqe_start_rx, the orqe's flag in the if condition is read using
> READ_ONCE, checked, and then re-read, voiding all guarantees of the
> checks. Reuse the value that was read by READ_ONCE to ensure the
> consistency of the flags throughout the function.

Please read include/asm-generic/rwonce.h comments when READ_ONCE() is used.
There is no value in caching the output of READ_ONCE().

Thanks