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Howlett" , akpm@linux-foundation.org, willy@infradead.org, lorenzo.stoakes@oracle.com, mhocko@suse.com, vbabka@suse.cz, hannes@cmpxchg.org, mjguzik@gmail.com, oliver.sang@intel.com, mgorman@techsingularity.net, david@redhat.com, peterx@redhat.com, oleg@redhat.com, dave@stgolabs.net, paulmck@kernel.org, brauner@kernel.org, dhowells@redhat.com, hdanton@sina.com, hughd@google.com, lokeshgidra@google.com, minchan@google.com, jannh@google.com, shakeel.butt@linux.dev, souravpanda@google.com, pasha.tatashin@soleen.com, klarasmodin@gmail.com, corbet@lwn.net, linux-doc@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, kernel-team@android.com Subject: Re: [PATCH v6 10/16] mm: replace vm_lock and detached flag with a reference count Message-ID: <20241219085515.GB26551@noisy.programming.kicks-ass.net> References: <20241218100601.GI12500@noisy.programming.kicks-ass.net> <20241218161850.GG2354@noisy.programming.kicks-ass.net> <20241218174428.GQ2354@noisy.programming.kicks-ass.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Rspamd-Server: rspam06 X-Rspamd-Queue-Id: B76D340003 X-Rspam-User: X-Stat-Signature: k55jq6cr4cwzodipuazt8331cuhdgxqe X-HE-Tag: 1734598490-448581 X-HE-Meta: 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 0exsWtFe Y1QF9KlEM+atc5V2NGhPTBpMAfWy8gantntNihqxU/8rmlN10YD/AjlVYgSigQxThj54Ie2ATnMVKRST8hQgQVVjoecdM920Mxox0ArfnEPfWNRTG58w5CYjn3b2KVKia5DHEzD29BvysiDRtdXUZNcT0yzi3Y4EWmgwJl7nKfRqOByP6lUIVZrY1kVl7bEl19O1suHtCQcaP5D/2wlH0MyAJTzKHKAjoZk5QXiWlgB1yWnk= 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, Dec 18, 2024 at 11:29:23AM -0800, Suren Baghdasaryan wrote: > Yeah, I think we can simply do this: > > vms_complete_munmap_vmas > vms_clear_ptes > remove_vma > vma_mark_detached > mmap_write_downgrade > > If my assumption is incorrect, assertion inside vma_mark_detached() > should trigger. I tried a quick test and so far nothing exploded. I think that would be unfortunate and could cause regressions. I think we want to keep vms_clear_ptes() under the read-lock.