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b=KqtuYhtv25KWFt6vqVb9KtRrmUdRt6EEg5OQl4q+pvTgATUNZ66VOxtY2VR47AeRM o8FMb4uxot39FFZZEEA4224SjOLKPfdXtYw81PiDATKN7UyiG0chazjW4Z/HeomrPZ qSEK7sPV97gfZuaSIBXTph461EQ+rZKA0v4Jlv83IMMhFDQjDohmtfmwvmfJ4xmjTw jqCrGKe+YGKYSzCMVdHOJ3zi/9j0Z/niaRdjU8yxDquV1Gz9Za2OLsaEqdwPaKMAkl mUr9dkQZ1HOPPV/4Q3GsljzzK1IkAF/RMQkIVSJFUr+6Ul1y+GYtIX9tgvjJNo8eKQ Ke3BDGZSWKWaA== Message-ID: Date: Tue, 24 Feb 2026 10:40:30 +0100 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v3 00/22] Add support for shared PTEs across processes To: Kalesh Singh , Anthony Yznaga Cc: linux-mm@kvack.org, akpm@linux-foundation.org, andreyknvl@gmail.com, arnd@arndb.de, bp@alien8.de, brauner@kernel.org, bsegall@google.com, corbet@lwn.net, dave.hansen@linux.intel.com, dietmar.eggemann@arm.com, ebiederm@xmission.com, hpa@zytor.com, jakub.wartak@mailbox.org, jannh@google.com, juri.lelli@redhat.com, khalid@kernel.org, liam.howlett@oracle.com, linyongting@bytedance.com, lorenzo.stoakes@oracle.com, luto@kernel.org, markhemm@googlemail.com, maz@kernel.org, mhiramat@kernel.org, mgorman@suse.de, mhocko@suse.com, mingo@redhat.com, muchun.song@linux.dev, neilb@suse.de, osalvador@suse.de, pcc@google.com, peterz@infradead.org, pfalcato@suse.de, rostedt@goodmis.org, rppt@kernel.org, shakeel.butt@linux.dev, surenb@google.com, tglx@linutronix.de, vasily.averin@linux.dev, vbabka@suse.cz, vincent.guittot@linaro.org, viro@zeniv.linux.org.uk, vschneid@redhat.com, willy@infradead.org, x86@kernel.org, xhao@linux.alibaba.com, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org References: <20250820010415.699353-1-anthony.yznaga@oracle.com> From: "David Hildenbrand (Arm)" Content-Language: en-US Autocrypt: addr=david@kernel.org; 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charset=UTF-8 Content-Transfer-Encoding: 7bit X-Stat-Signature: ttq3ema3aqdi7rtzw9timdcw1d9og7ix X-Rspamd-Server: rspam11 X-Rspam-User: X-Rspamd-Queue-Id: 9F945C0007 X-HE-Tag: 1771926043-631910 X-HE-Meta: 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 wz1D2yFm 48bQ1W/3Kxmh4EFnxNPfUdsm7ZTpKYAQBae12d3FtE428/fUDYexxvXWnw7YPR+zlugnLh1DGIfcW8cHoVeycWFwqfuUWXn21m2/HKU1YsBDn1dCQD7G6vyvxohsQBlnE5dQwpPu/ACQ24Yt/twwqKK5EYTqO4VOqvree/kyrPm5aigOtND4x09E2fj76GmzlW274F9M7GRkzsKnj1VSHWoQp1w9xnrtjRSO2TGObX67BCDS06eOGQ4+pyoUzehtmsdbS 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: > I believe that managing a pseudo-filesystem (msharefs) and mapping via > ioctl during process creation could introduce overhead that impacts > app startup latency. Ideally, child apps shouldn't be aware of this > sharing or need to manage the pseudo-filesystem on their end. All process must be aware of these special semantics. I'd assume that fork() would simply replicate mshare region into the fork'ed child process. So from that point of view, it's "transparent" as in "no special mshare() handling required after fork". -- Cheers, David