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b=bqIZIXJdo1vgb4dJgvLtTgj1mBU5YPAQ2rZJDKygUJMuEwOxOdUigrAwjHoR5DIxk sa43vkpKRRl1zIBPdWhEGtIGoKIU/2My9OJ254/pMQpThUqd52zCUV//0Ddr3kR1NE 1URG4Tbp4OEPwicJVM8iMnaBwSpDPkwK/fYu6qbU= Date: Wed, 7 May 2025 14:54:02 -0700 From: Andrew Morton To: Pantelis Antoniou Cc: , , Artem Krupotkin , Charles Briere , Wade Farnsworth Subject: Re: [PATCH 0/1] Fix zero copy I/O on __get_user_pages allocated pages Message-Id: <20250507145402.d162d92fa29130d690461a0b@linux-foundation.org> In-Reply-To: <20250507154105.763088-1-p.antoniou@partner.samsung.com> References: <20250507154105.763088-1-p.antoniou@partner.samsung.com> X-Mailer: Sylpheed 3.7.0 (GTK+ 2.24.33; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Rspamd-Server: rspam10 X-Rspamd-Queue-Id: 0F11820015 X-Stat-Signature: 9scxixgrrfw69chmcsbxksixxke85mms X-Rspam-User: X-HE-Tag: 1746654843-759246 X-HE-Meta: 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 jqpNCUP+ ukUZK6qR9F03DcfhQRJeuu7IecsTaCedhrUqjnkbUBZjXJLkkj7/vF1BJXEDKwc344MEGcVlsz2e5NsXTCwVkEi0LM+sXzS/iY/5s96GQdThvxWEr0+8rwJoudpxzFkfzd/yjLd2+wFypOq4S+HMmDOjBkF4CJHX22KmGB5b00b+j5h68oFKSvj9GilCZcT7bz2BugR7OhLiKrcMMPmW4nhHCLUhABzmNNLm4bGsQBtxBGfidqbj50p1LGBUXuCUxbttXwpTKkC+BWyQZjzRKMpFO74PdF1R6aTXX6sgrCPjqhmVASsLjfN0IOgL0EAzV5zyZ X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Wed, 7 May 2025 10:41:04 -0500 Pantelis Antoniou wrote: > One example of that is the 9p filesystem which is commonly used in qemu > based setups for sharing files with the host. > > In our emulation environment we have noticed failing writes when performing > I/O from a userspace mapped DRM GEM buffer object. > The platform does not use VRAM, all graphics memory is regular DRAM memory, > allocated via __get_free_pages > > The same write was successful from a heap allocated bounce buffer. > > The sequence of events is as follows. > > .. > There's a lot of good stuff in this [0/N], but a single patch "series" is cumbersome. Can you please redo this as a standalone patch in which the changelog is the union of [0/1] and [1/1]?