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[159.2.73.22]) by smtp.gmail.com with ESMTPSA id 6a1803df08f44-8a593bf6741sm151891956d6.18.2026.04.06.15.43.15 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 06 Apr 2026 15:43:15 -0700 (PDT) Received: from jgg by wakko with local (Exim 4.97) (envelope-from ) id 1w9sf4-0000000E5IQ-2nq6; Mon, 06 Apr 2026 19:43:14 -0300 Date: Mon, 6 Apr 2026 19:43:14 -0300 From: Jason Gunthorpe To: Pranjal Shrivastava Cc: Nafees Ahmed Abdul , joro@8bytes.org, will@kernel.org, robin.murphy@arm.com, iommu@lists.linux.dev, linux-kernel@vger.kernel.org Subject: Re: [RFC PATCH] iommu: Default to lazy DMA mode on ARM64 Message-ID: <20260406224314.GL2551565@ziepe.ca> References: <20260402195913.32084-1-nafeabd@amazon.com> Precedence: bulk X-Mailing-List: iommu@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: On Fri, Apr 03, 2026 at 02:28:17AM +0000, Pranjal Shrivastava wrote: > Thanks for the patch and the benchmarks. > > However, I'm not sure why should we change the compile-time default for > all ARM64 systems? Currently, users can already achieve this behavior by > using the `iommu.strict=0` boot parameter. Personally I really dislike these rando arch specific things. What justification is there for any arch to be unique here? I'd expect a single kconfig 'try to be strict by default' and that's it. No arch override. Jason