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b=mT78I1gFIY4l4WwOgJH7IieNz0sn6nIuBxmmWb3IyS/Mic/VyR47jeWT0UemhLBUa lRbZdGhDE2zSzr7DaWqqQLtoGUQfdKckmB/8wBvY5rWRi4ed0Wn+HCJuTQl3uDx/zm 3a1con5c7Eb8RkywRL2qLIFxohlyLZvZpntWOzWcIqNDf4vHwtOXM3D7rblgOnvvja sSme+E9Kv/MA4YfeqImXUQpOxNsfMxLKND+i49gTTDw1ieTM2cycEnWKeRlHUIOZfR IMAH8aGv9LL60jzFAH81CjVa4mrqHve3323I9WwMeV4ItZ/ijS3UyCzDhc2bOIypsF h2BdPR38VizVg== Date: Thu, 3 Sep 2026 12:20:47 +0300 From: Mike Rapoport To: Dave Hansen Cc: Xueyuan Chen , akpm@linux-foundation.org, david@kernel.org, ljs@kernel.org, usama.arif@linux.dev, ziy@nvidia.com, baolin.wang@linux.alibaba.com, liam@infradead.org, nico.pache@linux.dev, ryan.roberts@arm.com, dev.jain@arm.com, baohua@kernel.org, lance.yang@linux.dev, kas@kernel.org, catalin.marinas@arm.com, will@kernel.org, mark.rutland@arm.com, linux-arm-kernel@lists.infradead.org, tglx@kernel.org, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, x86@kernel.org, hpa@zytor.com, luto@kernel.org, peterz@infradead.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v7 1/3] mm: make persistent huge zero folio read-only Message-ID: References: <20260901151818.3191443-1-xueyuan.chen21@gmail.com> <20260901151818.3191443-2-xueyuan.chen21@gmail.com> <5026dbec-0b71-4408-a78a-484a4b8e77dd@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <5026dbec-0b71-4408-a78a-484a4b8e77dd@intel.com> X-Rspamd-Server: rspam05 X-Rspamd-Queue-Id: AD1D920007 X-Stat-Signature: 4ewomntikidxbytyx3t7otua1zwxosxx X-Rspam-User: X-HE-Tag: 1788427261-518822 X-HE-Meta: U2FsdGVkX19/7vx0NKjO61pnIqVknu4zXPtO198hETSIercNlLKAWbFJZP3yBfEDDWAhvy0IRBlbNRFpzhUED2rk5LWMzUcwwgvHbWq4HaRsILiqBHXPcF1TpALiH38sF62B2+fFsLDiZAEzJIFBQrxI/bLI59OFEprxIRawA2JkUcj+qd83rE887NaNUDMsEjqxhY8yNhio7spwkAWXP/Su8pOSy9jYX22IrJu6ekvKhIVipHqTZBY8PCY/o3wF6tvMB204MjE97g0IBQUGO194IAGh1e8PAExeYW2u3MHcOA9pEWfY/Wsu7oAFiWs93lF71msRrSXe3A29ixfaQ35MpiFqTwrhVeK/S7hvmvijcSxjZdv/xgxgRLnUByyDNA8TBXvBV0zAWKk21bj5Ug7Ff86jpNv1pPyTl718dMcm8zLN/CSmXIfYZJygvs53+QR76QW4I/Xm7yl1HlPP8nD4Ljma4PwNrgf4DIGcw42c+NJBAaFLJtMZw+zA0eKGpATuP4SidJUJq0fmHaUyaCFnmll6IqwIDda0MFJPr7xm+ndrXGwtBZ4TQ8eCwKLp/zZghgnwd5cMiAClvysBGC1VMnPmh6ESSfCJZ0jHXwZjDH39rPsNvRtTBftkuNfawpL98i3rhuKIXjSDpMEDikheZKYMjiJAjxfyMm+iCrBmcdedTBFRxsvx1wKVrQizJUkjy7t9JA0wLhNIlTTezSabGcMC7ktMIC2TygZEPjuvzIUvZQtLc8AfsHdH7FWMfimOHRyEce+CrQTfbmcVLinL7YWklacsHEeys6oXRdgFQrb9TplPa0xhRdBKfRHcFYGaZ/9He7RQ0+DwkbIg1t2qWEj9p3F3nve2lEyBmiT1Z+xaMdy8FLu0kiC+04gu6j8J+yPU8L9KRJdvjqNbti6+DYXVGTnc52GdbIU9SuKmZAkJX6uAQtUHYfo9r5Cw//a/mJuQlS6znV0rkeM Uf96Xrka UFZFVetiDpU6HYZTuByo0fbDZ/IAqDZr1qia8D/5kAh9xbslqdwwbk2+qhV0lg2MRB4MEmRXSiXNSqRdiOrRBIFai+FyZ05IfK+0bi5cVS3vLBv3TasJaNJb9F/Fuo5JI+U6owtzoMpuUAJvSa5mqgfs+OQ5/OT0jeioiZWMVJOODQuSBgyzBfCLMQY5RTNQU1ZhBE2WcJ3B7sscFcpadrJ3H1EOE0xd52oakq0CkD03+VRx0OH3JqKR0SF5xnk0u51R/p8s1upHwUfjuLBkI9lzPI7kXZy9tF1R/qYc7LuIgzX113tnAFOjcTRK9vWs3y302y+Of9u9YNz0= Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: Hi Dave, On Wed, Sep 02, 2026 at 01:59:15PM -0700, Dave Hansen wrote: > On 9/1/26 08:18, Xueyuan Chen wrote: > > +static inline int set_direct_map_ro(struct page *page, unsigned int nr) > > +{ > > + return 0; > > +} > > I still really think the stub here needs to return an error *or* the > thing needs to just be void and tell folks that they can't know whether > it worked or not. All other stubs return 0 here when an arch does not support set_direct_map. I'm for keeping them all consistent and fixing that technical debt as a whole rather than creating a one-off here. -- Sincerely yours, Mike.