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McKenney" Cc: Tejun Heo , Andrea Righi , sched-ext@lists.linux.dev, linux-kernel@vger.kernel.org, kernel-team@cloudflare.com Subject: Re: sched_ext/lavd hard lockup in old call_rcu_tasks_generic needadjust path Message-ID: References: <20260609104733.1184001-1-mfleming@cloudflare.com> <2179fc11-3bd5-4d2e-9ad8-609e3356ec09@paulmck-laptop> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <2179fc11-3bd5-4d2e-9ad8-609e3356ec09@paulmck-laptop> On Tue, Jun 09, 2026 at 04:23:23AM -0700, Paul E. McKenney wrote: > > Does commenting out the 'call_rcu_tasks_generic+547' printk() avoid the > issue? If so, that printk() might be deferred or some such. > > "But if you cannot trust printk(), what *can* you trust?" ;-) I tried this and it still crashes so apparently not! I'll keep digging to find the real cause (it's somewhat cumbersome to reproduce this hard lockup).