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[85.239.239.237]) by smtp.gmail.com with ESMTPSA id d9443c01a7336-2df5d0588e9sm6100495ad.76.2026.09.22.01.44.59 (version=TLS1_3 cipher=TLS_CHACHA20_POLY1305_SHA256 bits=256/256); Tue, 22 Sep 2026 01:45:16 -0700 (PDT) From: Lian Wang To: Boqun Feng Cc: Kunwu Chan , stern@rowland.harvard.edu, parri.andrea@gmail.com, will@kernel.org, peterz@infradead.org, npiggin@gmail.com, dhowells@redhat.com, j.alglave@ucl.ac.uk, luc.maranget@inria.fr, paulmck@kernel.org, corbet@lwn.net, mingo@redhat.com, dave@stgolabs.net, josh@joshtriplett.org, frederic@kernel.org, neeraj.upadhyay@kernel.org, urezki@gmail.com, akiyks@gmail.com, dlustig@nvidia.com, joelagnelf@nvidia.com, skhan@linuxfoundation.org, rdunlap@infradead.org, longman@redhat.com, rostedt@goodmis.org, mathieu.desnoyers@efficios.com, jiangshanlai@gmail.com, qiang.zhang@linux.dev, include@grrlz.net, linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org, lkmm@lists.linux.dev, linux-doc@vger.kernel.org, rcu@vger.kernel.org, lianux.mm@gmail.com Subject: Re: [RFC/WIP PATCH 1/4] hazptr: add shared-scan kthread Date: Tue, 22 Sep 2026 16:44:37 +0800 Message-ID: <20260922084447.58084-1-lianux.mm@gmail.com> X-Mailer: git-send-email 2.55.0 In-Reply-To: References: <20260922070950.4173245-1-kunwu.chan@gmail.com> <20260922070950.4173245-2-kunwu.chan@gmail.com> Precedence: bulk X-Mailing-List: linux-arch@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Hi Boqun, Thanks for the suggestion. Kunwu and I will work together on the next iteration of the shared-scan design, including your idea of avoiding per-synchronize allocations with a Bloom filter. We will also run the rcuscale comparisons and collect IPI counts for the lockdep workloads you suggested, then share the results with the thread. Thanks, Lian On Tue, 22 Sep 2026 10:28:24 +0200 Boqun Feng wrote: > This would requires allocation during hazptr_synchronize() and I would > like to avoid that (it's going to introduce a "allocating memory to free > memory" case). > > Mathieu brought up a useful data structure for the scan: A Bloom filter: > > Willing to give it a try?