Received-SPF: pass (google.com: domain of linux-kernel+bounces-25820-linux.lists.archive=gmail.com@vger.kernel.org designates 147.75.199.223 as permitted sender) client-ip=147.75.199.223;
Date: Mon, 15 Jan 2024 17:37:41 +0800
From: Jisheng Zhang <jszhang@kernel.org>
To: Paul Walmsley <paul.walmsley@sifive.com>,
	Palmer Dabbelt <palmer@dabbelt.com>,
	Albert Ou <aou@eecs.berkeley.edu>
Cc: linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2 0/2] riscv: enable lockless lockref implementation
Message-ID: <ZaT85b/FUDe9frUz@xhacker>
References: <20231202140323.315-1-jszhang@kernel.org>
Precedence: bulk
MIME-Version: 1.0
Content-Type: text/plain; charset=utf-8
Content-Disposition: inline
In-Reply-To: <20231202140323.315-1-jszhang@kernel.org>

On Sat, Dec 02, 2023 at 10:03:21PM +0800, Jisheng Zhang wrote:
> This series selects ARCH_USE_CMPXCHG_LOCKREF to enable the
> cmpxchg-based lockless lockref implementation for riscv. Then,
> implement arch_cmpxchg64_{relaxed|acquire|release}.
> 
> After patch1:
> Using Linus' test case[1] on TH1520 platform, I see a 11.2% improvement.
> On JH7110 platform, I see 12.0% improvement.
> 
> After patch2:
> on both TH1520 and JH7110 platforms, I didn't see obvious
> performance improvement with Linus' test case [1]. IMHO, this may
> be related with the fence and lr.d/sc.d hw implementations. In theory,
> lr/sc without fence could give performance improvement over lr/sc plus
> fence, so add the code here to leave performance improvement room on
> newer HW platforms.
> 
> Link: http://marc.info/?l=linux-fsdevel&m=137782380714721&w=4 [1]

Hi Palmer,

this series is also missed, let me know if there's something need to be
done.

Thanks
> 
> Since v1:
>   - only select ARCH_USE_CMPXCHG_LOCKREF if 64BIT
> 
> Jisheng Zhang (2):
>   riscv: select ARCH_USE_CMPXCHG_LOCKREF
>   riscv: cmpxchg: implement arch_cmpxchg64_{relaxed|acquire|release}
> 
>  arch/riscv/Kconfig               |  1 +
>  arch/riscv/include/asm/cmpxchg.h | 18 ++++++++++++++++++
>  2 files changed, 19 insertions(+)
> 
> -- 
> 2.42.0
> 
> 
> _______________________________________________
> linux-riscv mailing list
> linux-riscv@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-riscv