From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from m16.mail.163.com (m16.mail.163.com [220.197.31.4]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 85E8D466B44 for ; Thu, 10 Sep 2026 10:51:39 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=220.197.31.4 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789037502; cv=none; b=GM/X/D55M20rIeJdqIC1mG9DPB8/njL1lAeymXJ8N++dp8mgkcJJSnsWg+ebA+ARozjw8hyKKrdZpvA4EecD1QvNyy2LzLG+io0KCpWRV2PgBocBkjxXApZsLOFT6vOCJCRgUeyElgzgWTRRva7kToXlK6eDk6UQrbmmuzveHwY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789037502; c=relaxed/simple; bh=5hQWqlOjQvOgrULRNQNvsDrFTg3ZUp9uEWavniukEpg=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=qt7IsTuKlZ0Cpxgn9nsK+DXPlrt23842YeuUnzT8oKsA7v9d7dkJVzWXLkcSP3N8QPxKsPSUM/+cGByo0//ZBMJm0szqcA/+3AGo5xA2iIBchIW8Y75sta8PnOEbJj3HDCZpeN77bcvUrux+cu96fK+ZICkOkhT2c8Zl8KKAZ18= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=163.com; spf=pass smtp.mailfrom=163.com; dkim=pass (1024-bit key) header.d=163.com header.i=@163.com header.b=lmJDR4Z+; arc=none smtp.client-ip=220.197.31.4 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=163.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=163.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=163.com header.i=@163.com header.b="lmJDR4Z+" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=163.com; s=s110527; h=From:To:Subject:Date:Message-ID:MIME-Version; bh=GR 7/FIwN5jSXQMlAo82lPv7zwqHGRXa2o1ep2UsTpec=; b=lmJDR4Z+NFUUaAKfX6 hiFukwvl3FfHXFL/i603dsrsvUb26dkCHPMccCLbKRMawMyGrCcmZ6v8Ds4nwzOa Ux7jO4qeJv5Y42nadPr2Qx6PQ0QYckxCJWBEwICCZAv0YYyTXxfyYZDXi+L/a61u 8Y5preSfJ8GSqwUY8p9XazDIs= Received: from localhost (unknown []) by gzsmtp5 (Coremail) with SMTP id QCgvCgCX1Bw4i6JqOwuKQw--.33571S2; Thu, 10 Sep 2026 18:49:29 +0800 (CST) From: Hui Su To: Andrea Righi Cc: peterz@infradead.org, mingo@redhat.com, tim.c.chen@linux.intel.com, yu.c.chen@intel.com, kprateek.nayak@amd.com, juri.lelli@redhat.com, vincent.guittot@linaro.org, dietmar.eggemann@arm.com, rostedt@goodmis.org, bsegall@google.com, mgorman@suse.de, vschneid@redhat.com, connoro@google.com, jstultz@google.com, tj@kernel.org, void@manifault.com, changwoo@igalia.com, linux-kernel@vger.kernel.org, sched-ext@lists.linux.dev Subject: Re: [PATCH v4 1/5] sched: Dispatch task ticks for donor and execution classes Date: Thu, 10 Sep 2026 19:49:28 +0900 Message-ID: <20260910104928.2771533-1-sh_def@163.com> X-Mailer: git-send-email 2.55.0 In-Reply-To: References: <20260909092901.2989564-2-sh_def@163.com> <20260909104251.3131056-1-sh_def@163.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 X-CM-TRANSID:QCgvCgCX1Bw4i6JqOwuKQw--.33571S2 X-Coremail-Antispam: 1Uf129KBjvJXoWxWr4xGw4rXF4Utry3Gw4rKrg_yoW5Xr4rpF Z5Kay5Kw1DtF1rAr47Zw48X3WrX397Gr1UWrWkArykurWYqry0gFyftF1jva1UWryfuFy2 vrs0vws7GFWjvaDanT9S1TB71UUUUU7qnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDUYxBIdaVFxhVjvjDU0xZFpf9x07UNBMNUUUUU= X-CM-SenderInfo: xvkbvvri6rljoofrz/xtbC6ho0k2qiizrGXwAA33 On Wed, Sep 09, 2026 at 07:43:44PM +0200, Andrea Righi wrote: > They should be compatible soon: > https://lore.kernel.org/r/20260831134338.1531664-1-arighi@nvidia.com/ > > It'd be good to handle SCX donor/execution context ownership in this serie as > well, or we can coordinate to figure out the required changes. > > I haven't looked at the whole patch series yet (will do soon), this is JFYI. :) Thanks for the heads-up. I kept task_tick_scx() explicitly donor-gated in the current local draft and did not duplicate the donor-accounting changes from your v13 series. The common task_tick() dispatcher invokes the donor class first and, when the execution class differs, invokes the execution class second. If sched_ext is reached only as the execution class for a non-EXT donor, task_tick_scx() returns without SCX policy or slice work. I previously applied your v13 series and an integration tree containing an earlier revision of this five-patch series on the same base. In that integration, the task_tick_scx() hunk was the only textual conflict I encountered. The current revision additionally handles retained-donor scheduling-class transitions around sched_change_begin() and sched_change_end(). Your v13 series also changes that transition path, so I have not revalidated the combined tree after this latest P4 change. The expected resolution still uses task_tick(rq, queued), derives the donor from rq->donor, keeps the explicit donor-class guard, and preserves your donor-based update_curr_scx() and SCX proxy accounting. That earlier combined integration tree built and booted with CONFIG_SCHED_CLASS_EXT=y and CONFIG_SCHED_PROXY_EXEC=y. It did not provide a stable full mixed EXT->FAIR, FAIR->EXT, EXT->EXT, and RT/DL->EXT runtime matrix, and it predates the current P4 transition changes. I am therefore not claiming complete runtime compatibility for the current revision. The resolved task-tick path in the integration tree is: struct task_struct *donor = rq->donor; if (donor->sched_class != &ext_sched_class) return; update_curr_scx(rq); /* donor-based in your series */ SCX_CALL_OP_TASK(sch, tick, rq, donor); if (!donor->scx.slice) resched_curr(rq); The complete conflict resolution is carried by the integration tree; this excerpt records the donor guard retained from this series and the donor accounting retained from yours. Could you take a look at whether this donor-gated integration is the right direction? If so, I will revalidate the current combined tree, carry the result into the series, and post it as v5 after the pending runtime checks. Thanks, Hui