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([2a01:e0a:999:a3a0:bf35:904f:7a0e:6c9a]) by smtp.gmail.com with ESMTPSA id fa29-20020a056a002d1d00b006e47b5b67d1sm979347pfb.77.2024.02.27.01.11.47 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 27 Feb 2024 01:11:54 -0800 (PST) Message-ID: Date: Tue, 27 Feb 2024 10:11:41 +0100 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] riscv: deprecate CONFIG_MMU=n To: Charles Lohr , Conor Dooley Cc: Samuel Holland , Paul Walmsley , Palmer Dabbelt , Albert Ou , linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org, Conor Dooley , Andrew Jones , Damien Le Moal , =?UTF-8?B?QmrDtnJuIFTDtnBlbA==?= , Atish Patra References: <20240226140649.293254-1-cleger@rivosinc.com> <40dee2c1-ff24-40b2-a13c-6934139ba869@sifive.com> <20240226-pajamas-okay-51e16426b0f5@spud> Content-Language: en-US From: =?UTF-8?B?Q2zDqW1lbnQgTMOpZ2Vy?= In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit On 26/02/2024 20:00, Charles Lohr wrote: > WOAH! Please DO NOT deprecate NOMMU. I use the NOMMU build constantly > and NOMMU Linux on RISC-V is the avenue used by many FPGA soft cores > for Linux, as well as some limited systems. > > I get new copies of the kernel when there are releases and test them > frequently to make sure everything is still working as expected. > > For us we just don't care about XIP. I mean if someone did push it > through to fruition, I'd also test and use it, but I urge you please > do not deprecate this. While it's sometimes needed a bit of a > creative build to get everything working, I've never needed to patch > anything in the kernel beyond patching in a custom console for serial > output. > Hey Charles, No worries, we actually did not expected NOMMU to have *so many* users. I guess deprecating stuff is a good way to have immediate feedback ;). Having FDPIC psABI to be merged upstream could also probably be a positive point toward a better NOMMU support. > I am happy to discuss the possibility of me and or one of the other > RISC-V soft (FPGA) core people stepping up to try to be more active, > but so far we've just been very well serviced by the current NOMMU > Linux setup. It could probably be nice to have some feedback/Tested-by: from NOMMU users for new releases then. Thanks, Clément > > Charles > > > On Mon, Feb 26, 2024 at 8:03 AM Conor Dooley wrote: >> >> On Mon, Feb 26, 2024 at 04:25:24PM +0100, Clément Léger wrote: >>> I guess I could also mark XIP as deprecated. >> >> I'm not so sure, people recently added XIP support to QEMU (and sent >> kernel fixes in December). XIP is also not nearly as much of a problem >> to support, there's far less that it does differently, the main barrier >> was the inability to test it which is no longer the case. >> That said, XIP is gonna kill itself off I feel as it does not support >> runtime patching and therefore is extremely limited on extensions, given >> we use alternatives for all of that (although I suppose if someone has a >> usecase they could make nasty macros worse and implement a compiletime >> switch in the alternatives too). >> >> Cheers, >> Conor. >> >> _______________________________________________ >> linux-riscv mailing list >> linux-riscv@lists.infradead.org >> http://lists.infradead.org/mailman/listinfo/linux-riscv