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Wed, 03 Dec 2025 06:29:19 -0800 (PST) X-Google-Smtp-Source: AGHT+IGfi8R1RN7PjMKEmyEZal0As/7EtQ7zH3DM3h+Mmmedhj2U9q3HO+FOQf1Rl7HsSVvrL2JlkQ== X-Received: by 2002:a05:6000:2484:b0:42b:3298:4690 with SMTP id ffacd0b85a97d-42f731a523emr2583862f8f.33.1764772158714; Wed, 03 Dec 2025 06:29:18 -0800 (PST) Received: from jlelli-thinkpadt14gen4.remote.csb ([151.29.129.40]) by smtp.gmail.com with ESMTPSA id ffacd0b85a97d-42e1ca78f77sm39941040f8f.32.2025.12.03.06.29.18 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 03 Dec 2025 06:29:18 -0800 (PST) Date: Wed, 3 Dec 2025 15:29:16 +0100 From: Juri Lelli To: David Haufe Cc: linux-kernel@vger.kernel.org Subject: Re: Kernel 6.14.11 dl_server_timer(...) causing IPI/Function Call Interrupts on isolcpu/nohz_full cores, performance regression Message-ID: References: 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: On 25/11/25 13:33, David Haufe wrote: > f237e524f3c7 ("sched/deadline: Make dl-server nohz full aware") <-- > patch applied > 219a63335b67 ("sched/deadline: Don't count nr_running twice for > dl_server proxy tasks") <-- exists in mainline 6.17 > 7620177e8108 ("sched/deadline: Fix RT task potential starvation when > expiry time passed") <-- exists in mainline 6.17 > cccb45d7c429 ("sched/deadline: Less agressive dl_server handling") <-- > slightly different code but exists in mainline 6.17 > > The "nohz full aware" patch does stop the hrtimer interrupts. I will > watch for that merge and can patch locally for now. Thank you! Thanks for testing and reporting! Unfortunately (as I mentioned) I will be soon traveling + pto until essentially next year. So, apologies, but I will most probably need to defer cleaning up and send out a proper version to beginning of 2026. Hope that's OK. Best, Juri