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Shutemov" , Jason Gunthorpe , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Andrew Morton , Jens Axboe , Matthew Wilcox , Dennis Dalessandro , Leon Romanovsky , Christian Benvenuti , Nelson Escobar , Bernard Metzler , Peter Zijlstra , Ingo Molnar , Arnaldo Carvalho de Melo , Mark Rutland , Alexander Shishkin , Jiri Olsa , Namhyung Kim , Ian Rogers , Adrian Hunter , Bjorn Topel , Magnus Karlsson , Maciej Fijalkowski , Jonathan Lemon , "David S . Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Christian Brauner , Richard Cochran , Alexei Starovoitov , Daniel Borkmann , Jesper Dangaard Brouer , John Fastabend , linux-fsdevel@vger.kernel.org, linux-perf-users@vger.kernel.org, netdev@vger.kernel.org, bpf@vger.kernel.org, Oleg Nesterov , Jan Kara , Pavel Begunkov , Mika Penttila , David Howells , Christoph Hellwig References: <077c4b21-8806-455f-be98-d7052a584259@lucifer.local> <62ec50da-5f73-559c-c4b3-bde4eb215e08@redhat.com> <6ddc7ac4-4091-632a-7b2c-df2005438ec4@redhat.com> <20230428160925.5medjfxkyvmzfyhq@box.shutemov.name> <39cc0f26-8fc2-79dd-2e84-62238d27fd98@redhat.com> <20230428162207.o3ejmcz7rzezpt6n@box.shutemov.name> <173337c0-14f4-3246-15ff-7fbf03861c94@redhat.com> <40fc128f-1978-42db-b9c1-77ac3c2cebfe@lucifer.local> <3d7fcfab-e445-1dc7-f000-9fbe7bea04c0@redhat.com> <7e096879-4578-36df-4809-3b04f4c20587@redhat.com> From: John Hubbard In-Reply-To: <7e096879-4578-36df-4809-3b04f4c20587@redhat.com> Content-Type: 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 g6doYaFO FVnSKmKVTcKK/oX9ME5lTIibNqzvoZjcPM0DJtJIvLIt+czXjq5nXaIbf1pIDk19s/BOTinoVK7vqCgbjTG5QKcm1i1PT/JvH3CdPS+QTu0bNkCiqRKg0vWxKUHBiaTKkVhaSb3992OaoYN1UiOx20NzWQrakZ0NFzHL2K5uefolzmxT/izVXHmGUPfOmv8HehTZQ5k8ingR9+Mu9AEUkiZwvC8sh1Lmjw/aV5K6IYStxZ7+0yIqExUJdlicYZFW+QjzIhVAuVNAqQJAeFSWj1DN5kgrrw8hl1els 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: On 4/28/23 10:29, David Hildenbrand wrote: ... >> Is that an issue with interrupts disabled though? Will block page tables being >> removed and as Kirill says (sorry I maybe misinterpreted you) we should be ok. > > Let's rule out page table freeing. If our VMA only spans a single page > and falls into the same PMD as another VMA, an munmap() would not even > free a single page table. > > However, if unmapping a page (flushing the TLB) would imply an IPI as > Kirill said, we'd be fine. I recall that that's not the case for all > architectures, but I might be just wrong. > Some architectures use IPIs, and others use an RCU-like approach instead. thanks, -- John Hubbard NVIDIA