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Thu, 15 Oct 2026 05:02:35 -0700 (PDT) From: Zhan Xusheng To: Christian Loehle Cc: Zhan Xusheng , Peter Zijlstra , Ingo Molnar , Balbir Singh , Juri Lelli , Vincent Guittot , Dietmar Eggemann , Valentin Schneider , Josh Snyder , Kayra Cizmeci , linux-kernel@vger.kernel.org Subject: Re: [PATCHv2] sched: Account I/O waits independently of delayed dequeue Date: Thu, 15 Oct 2026 20:02:27 +0800 Message-ID: <20261015120227.1929531-1-zhanxusheng1024@gmail.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: References: <20261014081731.1068794-1-zhanxusheng@xiaomi.com> <4ce12bff-9532-4b27-98f2-a807bbccfaf7@arm.com> <20261015025912.1541134-1-zhanxusheng@xiaomi.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Zhan Xusheng On 10/15/26 12:37, Christian Loehle wrote: > Save the CPU charged at the start of the wait. Delayed tasks can migrate > while still queued, and proxy execution can also move blocked tasks. > Decrement the saved CPU's counter on unblock, regardless of the task's > current placement, and remove the old dequeue-based accounting. This addresses what I reported, and the nr_iowait pairing holds for the paths I could find, including the should_block == false one where the decrement comes from find_proxy_task(). Reviewed-by: Zhan Xusheng