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Thu, 29 Oct 2026 07:49:03 -0700 (PDT) Received: from andreayoga.localdomain ([151.57.246.226]) by smtp.gmail.com with ESMTPSA id 5b1f17b1804b1-4aa7f322c46sm66634665e9.2.2026.10.29.07.49.00 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 29 Oct 2026 07:49:02 -0700 (PDT) From: Andrea Parri To: KunWu Chan Cc: Andrea Parri , "Paul E. McKenney" , Mathieu Desnoyers , Frederic Weisbecker , Neeraj Upadhyay , Joel Fernandes , Josh Triplett , Boqun Feng , Uladzislau Rezki , Steven Rostedt , Lai Jiangshan , Zqiang , Gary Guo , Bradley Morgan , rcu@vger.kernel.org, lkmm@lists.linux.dev, linux-kernel@vger.kernel.org Subject: Re: [PATCH -rcu/dev 0/4] hazptrtorture: Fix shutdown hang and catch slot owner race Date: Thu, 29 Oct 2026 15:48:53 +0100 Message-ID: <20261029144855.213308-1-parri.andrea@gmail.com> X-Mailer: git-send-email 2.53.0 In-Reply-To: References: <20261027163811.2470569-1-parri.andrea@gmail.com> X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit On Thu, Oct 29, 2026 at 05:58:27PM +0800, KunWu Chan wrote: > I ran into both issues independently while developing new shared-scan > hazptr series and its torture-test scenarios. Thank you for testing these, and for the arm64 data points! [...] > Paul's concern about `torture_must_stop()` is valid: `fullstop` can make the > drainer exit before the readers have stopped, so its exit-time flush is not > necessarily final. The reader-exit approach looks worth testing against both > the forced-slowpath case and the PREEMPT scenario Andrea reported. do_pending does leave its loop then, but v1's for_each_possible_cpu() pass comes after torture_kthread_stopping(), which returns only once hazptr_torture_cleanup() stops do_pending, after the readers. Either way, I have been testing Paul's suggestion of a pass after each reader's loop, without v1's pass in do_pending. [...] > These tests independently reproduced both issues in my setup. I'll check the > final cleanup approach against the forced-slowpath scenario as the > series settles. That would be very helpful, thank you. Thanks, Andrea