Re: [PATCH] RDMA/siw: Reuse value read using READ_ONCE instead of re-reading it

From: Greg Sword
Date: Sun Mar 10 2024 - 13:02:40 EST


On Sun, Mar 10, 2024 at 7:33 PM Leon Romanovsky <leon@xxxxxxxxxx> wrote:
>
> 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().

Agree. Read the link
https://www.kernel.org/doc/Documentation/memory-barriers.txt, too

>
> Thanks
>