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X-CSE-ConnectionGUID: 7aAl2lObRcCKLnytua4BRA== X-CSE-MsgGUID: OXElFItwSy21sXj40CMxDw== X-IronPort-AV: E=McAfee;i="6800,10657,11718"; a="77474979" X-IronPort-AV: E=Sophos;i="6.21,322,1763452800"; d="scan'208";a="77474979" Received: from orviesa007.jf.intel.com ([10.64.159.147]) by fmvoesa106.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 03 Mar 2026 09:27:23 -0800 X-CSE-ConnectionGUID: 8ZhSIOPKR+OzFv7fTjk7gA== X-CSE-MsgGUID: a3K4UJemS/285Bk9s+1SQg== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.21,322,1763452800"; d="scan'208";a="218189779" Received: from igk-lkp-server01.igk.intel.com (HELO 9958d990ccf2) ([10.211.93.152]) by orviesa007.jf.intel.com with ESMTP; 03 Mar 2026 09:27:21 -0800 Received: from kbuild by 9958d990ccf2 with local (Exim 4.98.2) (envelope-from ) id 1vxTWf-000000001Vx-2re1; Tue, 03 Mar 2026 17:27:17 +0000 Date: Tue, 3 Mar 2026 18:26:54 +0100 From: kernel test robot To: Tommaso Cucinotta , Peter Zijlstra Cc: oe-kbuild-all@lists.linux.dev, Tommaso Cucinotta , Juri Lelli , Jonathan Corbet , Shuah Khan , Shashank Balaji , linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] sched/deadline: document new sched_getattr() feature for retrieving current parameters for DEADLINE tasks Message-ID: <202603031858.JyW2vicC-lkp@intel.com> References: <20260303104215.1324243-1-tommaso.cucinotta@santannapisa.it> Precedence: bulk X-Mailing-List: linux-doc@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: <20260303104215.1324243-1-tommaso.cucinotta@santannapisa.it> Hi Tommaso, kernel test robot noticed the following build warnings: [auto build test WARNING on f74d204baf9febf96237af6c1d7eff57fba7de36] url: https://github.com/intel-lab-lkp/linux/commits/Tommaso-Cucinotta/sched-deadline-document-new-sched_getattr-feature-for-retrieving-current-parameters-for-DEADLINE-tasks/20260303-184545 base: f74d204baf9febf96237af6c1d7eff57fba7de36 patch link: https://lore.kernel.org/r/20260303104215.1324243-1-tommaso.cucinotta%40santannapisa.it patch subject: [PATCH] sched/deadline: document new sched_getattr() feature for retrieving current parameters for DEADLINE tasks compiler: clang version 20.1.8 (https://github.com/llvm/llvm-project 87f0227cb60147a26a1eeb4fb06e3b505e9c7261) docutils: docutils (Docutils 0.21.2, Python 3.13.5, on linux) reproduce: (https://download.01.org/0day-ci/archive/20260303/202603031858.JyW2vicC-lkp@intel.com/reproduce) If you fix the issue in a separate patch/commit (i.e. not just a new version of the same patch/commit), kindly add following tags | Reported-by: kernel test robot | Closes: https://lore.kernel.org/oe-kbuild-all/202603031858.JyW2vicC-lkp@intel.com/ All warnings (new ones prefixed by >>): Checksumming on output with GSO ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ [docutils] >> Documentation/scheduler/sched-deadline.rst:631: WARNING: Inline interpreted text or phrase reference start-string without end-string. [docutils] Documentation/userspace-api/landlock:480: ./security/landlock/errata/abi-4.h:5: ERROR: Unexpected section title. vim +631 Documentation/scheduler/sched-deadline.rst 615 616 Specifying a periodic/sporadic task that executes for a given amount of 617 runtime at each instance, and that is scheduled according to the urgency of 618 its own timing constraints needs, in general, a way of declaring: 619 620 - a (maximum/typical) instance execution time, 621 - a minimum interval between consecutive instances, 622 - a time constraint by which each instance must be completed. 623 624 Therefore: 625 626 * a new struct sched_attr, containing all the necessary fields is 627 provided; 628 * the new scheduling related syscalls that manipulate it, i.e., 629 sched_setattr() and sched_getattr() are implemented. 630 > 631 The leftover runtime and absolute deadline of a SCHED_DEADLINE task can be 632 read using the sched_getattr() syscall, setting the last syscall parameter 633 `flags' to the SCHED_GETATTR_FLAG_DL_DYNAMIC=1 value. This updates the 634 runtime left, converts the absolute deadline in CLOCK_MONOTONIC reference, 635 then returns these parameters to user-space. The absolute deadline is 636 returned as the number of nanoseconds since the CLOCK_MONOTONIC time 637 reference (boot instant), as a u64 in the sched_deadline field of sched_attr, 638 which can represent nearly 585 years since boot time (calling sched_getattr() 639 with flags=0 causes retrieval of the static parameters instead). 640 641 For debugging purposes, these parameters can also be retrieved through 642 /proc//sched (entries dl.runtime and dl.deadline, both values in ns), 643 but: this is highly inefficient; the returned runtime left is not updated as 644 done by sched_getattr(); the deadline is provided in kernel rq_clock time 645 reference, that is not directly usable from user-space. 646 647 -- 0-DAY CI Kernel Test Service https://github.com/intel/lkp-tests/wiki