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Mon, 10 Feb 2025 20:01:28 -0800 (PST) Date: Mon, 10 Feb 2025 20:01:26 -0800 From: Deepak Gupta To: Chunyan Zhang Cc: =?iso-8859-1?Q?Bj=F6rn_T=F6pel?= , Chunyan Zhang , Palmer Dabbelt , Albert Ou , Paul Walmsley , Alexandre Ghiti , Andrew Morton , linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org, Alistair Popple , linux-mm@kvack.org Subject: Re: [PATCH V5 1/3] riscv: mm: Prepare for reusing PTE RSW bit(9) Message-ID: References: <20241113095833.1805746-1-zhangchunyan@iscas.ac.cn> <20241113095833.1805746-2-zhangchunyan@iscas.ac.cn> <87frl0snf6.fsf@all.your.base.are.belong.to.us> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1; format=flowed Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: On Tue, Feb 11, 2025 at 09:20:22AM +0800, Chunyan Zhang wrote: >On Thu, 30 Jan 2025 at 16:42, Björn Töpel wrote: >> >> Chunyan Zhang writes: >> >> > The PTE bit(9) on RISC-V is reserved for software, it is used by devmap >> > now which has to be disabled if we want to use bit(9) for other features, >> > since there's no more free PTE bit on RISC-V now. >> > >> > So to make ARCH_HAS_PTE_DEVMAP selectable, this patch uses it as >> > the build condition of devmap definitions. >> >> Heads-up: It seems like Alistair's series [1] that removes the devmap >> PTE bit will most likely land in 6.15. > >Yes, I've been keeping an eye on Alistair's series, intended to update >this patchset after Alistair's patch that removes the devmap PTE bit >got merged. Please keep in mind that even after claiming back devmap PTE SW bit, a compile time decision to select between uffd-wp and soft-dirty is not desirable. > >Thanks, >Chunyan >> >> >> Björn >> >> [1] https://lore.kernel.org/linux-mm/cover.11189864684e31260d1408779fac9db80122047b.1736488799.git-series.apopple@nvidia.com/ >