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Howlett" , Vlastimil Babka , Jann Horn , Pedro Falcato , Shakeel Butt , linux-kernel@vger.kernel.org, linux-mm@kvack.org, stable@vger.kernel.org Subject: Re: [PATCH] fs/proc/task_mmu: fix missed VMAs when reading /proc/PID/maps and friends Message-ID: References: <20261025-per_vma_maps-v1-1-c4eec45b9387@kernel.org> <8c5a8fb7-233e-4433-af45-b67cb2528b60@kernel.org> X-Archived-By: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <8c5a8fb7-233e-4433-af45-b67cb2528b60@kernel.org> X-Rspamd-Queue-Id: 26FFE40004 X-Rspam-User: X-Stat-Signature: roxskj3uq9kw8ikmb7kojjasqtrezw3g X-Spam-Status: No, score=-6.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_PASS,SPF_PASS autolearn=no autolearn_force=no version=4.0.1 X-Rspamd-Server: rspam03 X-HE-Tag: 1793035587-16687 X-HE-Meta: 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 ZyOIk+hj ekU6pu0kjtIvsQiZGPGndWaiespOTJwYY9DJF98Jkt6DeYMKjysySXlwN+sf8/PcvtP6SkExaMfCkhnT4EUv/fbgpPBocWi7KQc2uKOi+Ipl4ajTaG2P7Hl1DIjPKsMeZzumr/FGnLZ65gcMkP2mFq89mbTzOnsh8td0GG72Sd4jxz9t8iOtFKSZi/8SYWxxeSrPLmjPAupIdhRlonJiQ08SRw2dJU6WDehJeA8+WsWJySpKRaSw+hFXsC7DWm4ceVOXC1v/0OsCMJNtUC0oqoH9920pwmaxaiZOhS4i3VvZpz98I7nXePIrjeM3W4A2Q7FJf Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: X-Spam-Checker-Version: SpamAssassin 4.0.1 (2024-03-26) on aws-us-west-2-korg-listserv-alma10-1 On Mon, Oct 26, 2026 at 06:19:18PM +0100, David Hildenbrand (Arm) wrote: > >> + /* > >> + * No lock was held since the last call, so the iterator's cached range > >> + * may no longer be valid. Always restart by address. > >> + * > >> + * The vma_range_is_empty() checks below avoid unnecessary mmap_lock > >> + * fallbacks. > >> + */ > >> + vma_iter_set(vmi, from_addr); > > > > This is clearly simpler but this unconditional vmi reset is not ideal. > > Yes, exactly how I ended up where we am right now. > > I pref my current fix as something to backport that avoids performance changes. > > If you two disagree, please take it over and drag it over the finishing line in > a timely manner. > > I wasted enough of my weekend with this over-enginered piece of software. (had > to change one word before sending, can you guess which :P ) No problem, will take over. -- Cheers, Lorenzo