From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.20]) (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 436FF38DEC; Mon, 22 Dec 2025 09:31:48 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.175.65.20 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1766395910; cv=none; b=U03yZ/gnPEjphKYbVXRBL/sJQn6kd9CN+QpJ4jXCMcQaSMhDa0H4jW+abWy6CdqSInufTPcyzfRZdmoww+ZB9qi/zdVWmTJamHNSOqzeGAPU6l9hNOK9V175V5/c/r+Q0whrcr+msV67Dfn3SKtndPIUMgm/fdSiv9urv+ag4Zo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1766395910; c=relaxed/simple; bh=qnUiNv3V9dqP60e7BcGstaSV3cjRHe8pm7xhofe8Q/Q=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=h29on9U2rLrBmtF1NtCiq2A6ce08MfpqY/VSxQmGqb8AiwBLFK5WRHQFDki3iTRDAW2LGz7ZFyV14LySQAOyMQlwYuPsHi+Uv4th5sh3Z2wK5+uQRsHSKcQgRiEG3tozj+elrq/FfGWF4jw1zKcgTrVg7ee341wcTlxTocmEncE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com; spf=pass smtp.mailfrom=intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=dHa/sua5; arc=none smtp.client-ip=198.175.65.20 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="dHa/sua5" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1766395908; x=1797931908; h=date:from:to:cc:subject:message-id:references: mime-version:in-reply-to; bh=qnUiNv3V9dqP60e7BcGstaSV3cjRHe8pm7xhofe8Q/Q=; b=dHa/sua5wXNLndyAp61e3+8hni1LS+9rreCsDVXVxsPh+usbDL2FdGzc GWu1ZuewqOjzlHUimmIOQWPv4ghtn7aOt/fcArN6g0jDzzXFw914GIKW8 dE863CFHQhwNPiBntCylQmxHeVd0KHdtOEMSpl1Gt3DeQfAyMD9Cyqj+2 JcFDBvJjA2CqSPVcOJX6exajTRI1rwd84sBT30WICnD04yoxI6WzFOdja oWGLE6x+rlLLdbQ/yQoyGx4b0/rBaafvWH7JxrePaiQ/JnaBAYHVUJnjS +X6FLN8GSuW1me2P9WyXAR0O7iRV4e4w2ISQGDIsOPuc1f0m4lsw1u2by g==; X-CSE-ConnectionGUID: gLCsEjB9QkyIQAyB7onASQ== X-CSE-MsgGUID: EE1UlZ2jS+6Dzhsn1bFiKw== X-IronPort-AV: E=McAfee;i="6800,10657,11649"; a="68003489" X-IronPort-AV: E=Sophos;i="6.21,167,1763452800"; d="scan'208";a="68003489" Received: from orviesa009.jf.intel.com ([10.64.159.149]) by orvoesa112.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 22 Dec 2025 01:31:48 -0800 X-CSE-ConnectionGUID: NDuSmUycRtWOBFruADL30w== X-CSE-MsgGUID: EowbdjfQR3m7f3nwp1RmhA== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.21,167,1763452800"; d="scan'208";a="199236189" Received: from lkp-server02.sh.intel.com (HELO dd3453e2b682) ([10.239.97.151]) by orviesa009.jf.intel.com with ESMTP; 22 Dec 2025 01:31:44 -0800 Received: from kbuild by dd3453e2b682 with local (Exim 4.98.2) (envelope-from ) id 1vXcGT-000000000KP-3M5u; Mon, 22 Dec 2025 09:31:41 +0000 Date: Mon, 22 Dec 2025 17:31:23 +0800 From: kernel test robot To: Wanpeng Li , Peter Zijlstra , Ingo Molnar , Thomas Gleixner , Paolo Bonzini , Sean Christopherson Cc: oe-kbuild-all@lists.linux.dev, K Prateek Nayak , Christian Borntraeger , Steven Rostedt , Vincent Guittot , Juri Lelli , linux-kernel@vger.kernel.org, kvm@vger.kernel.org, Wanpeng Li Subject: Re: [PATCH v2 5/9] sched/fair: Wire up yield deboost in yield_to_task_fair() Message-ID: <202512221734.SzKNollL-lkp@intel.com> References: <20251219035334.39790-6-kernellwp@gmail.com> Precedence: bulk X-Mailing-List: kvm@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: <20251219035334.39790-6-kernellwp@gmail.com> Hi Wanpeng, kernel test robot noticed the following build errors: [auto build test ERROR on kvm/queue] [also build test ERROR on kvm/next tip/sched/core peterz-queue/sched/core tip/master linus/master v6.19-rc2 next-20251219] [cannot apply to kvm/linux-next tip/auto-latest] [If your patch is applied to the wrong git tree, kindly drop us a note. And when submitting patch, we suggest to use '--base' as documented in https://git-scm.com/docs/git-format-patch#_base_tree_information] url: https://github.com/intel-lab-lkp/linux/commits/Wanpeng-Li/sched-fair-Add-rate-limiting-and-validation-helpers/20251219-125353 base: https://git.kernel.org/pub/scm/virt/kvm/kvm.git queue patch link: https://lore.kernel.org/r/20251219035334.39790-6-kernellwp%40gmail.com patch subject: [PATCH v2 5/9] sched/fair: Wire up yield deboost in yield_to_task_fair() config: i386-randconfig-003-20251222 (https://download.01.org/0day-ci/archive/20251222/202512221734.SzKNollL-lkp@intel.com/config) compiler: gcc-12 (Debian 12.4.0-5) 12.4.0 reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20251222/202512221734.SzKNollL-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/202512221734.SzKNollL-lkp@intel.com/ All errors (new ones prefixed by >>): ld: kernel/sched/fair.o: in function `yield_deboost_calculate_penalty': >> kernel/sched/fair.c:9213:(.text+0x278d): undefined reference to `__udivdi3' vim +9213 kernel/sched/fair.c 9a700d273608de Wanpeng Li 2025-12-19 9176 9a700d273608de Wanpeng Li 2025-12-19 9177 /* 9a700d273608de Wanpeng Li 2025-12-19 9178 * Calculate vruntime penalty for yield deboost. 9a700d273608de Wanpeng Li 2025-12-19 9179 * 9a700d273608de Wanpeng Li 2025-12-19 9180 * The penalty is based on: 9a700d273608de Wanpeng Li 2025-12-19 9181 * - Fairness gap: vruntime difference between yielding and target tasks 9a700d273608de Wanpeng Li 2025-12-19 9182 * - Scheduling granularity: base unit for penalty calculation 9a700d273608de Wanpeng Li 2025-12-19 9183 * - Queue size: adaptive caps to prevent starvation in larger queues 9a700d273608de Wanpeng Li 2025-12-19 9184 * 9a700d273608de Wanpeng Li 2025-12-19 9185 * Queue-size-based caps (multiplier of granularity): 9a700d273608de Wanpeng Li 2025-12-19 9186 * 2 tasks: 6.0x - Strongest push for 2-task ping-pong scenarios 9a700d273608de Wanpeng Li 2025-12-19 9187 * 3 tasks: 4.0x 9a700d273608de Wanpeng Li 2025-12-19 9188 * 4-6: 2.5x 9a700d273608de Wanpeng Li 2025-12-19 9189 * 7-8: 2.0x 9a700d273608de Wanpeng Li 2025-12-19 9190 * 9-12: 1.5x 9a700d273608de Wanpeng Li 2025-12-19 9191 * >12: 1.0x - Minimal push to avoid starvation 9a700d273608de Wanpeng Li 2025-12-19 9192 * 9a700d273608de Wanpeng Li 2025-12-19 9193 * Returns the calculated penalty value. 9a700d273608de Wanpeng Li 2025-12-19 9194 */ 9a700d273608de Wanpeng Li 2025-12-19 9195 static u64 __maybe_unused 9a700d273608de Wanpeng Li 2025-12-19 9196 yield_deboost_calculate_penalty(struct rq *rq, struct sched_entity *se_y_lca, 9a700d273608de Wanpeng Li 2025-12-19 9197 struct sched_entity *se_t_lca, 9a700d273608de Wanpeng Li 2025-12-19 9198 struct task_struct *p_target, int h_nr_queued) 9a700d273608de Wanpeng Li 2025-12-19 9199 { 9a700d273608de Wanpeng Li 2025-12-19 9200 u64 gran, need, penalty, maxp; 9a700d273608de Wanpeng Li 2025-12-19 9201 u64 weighted_need, base; 9a700d273608de Wanpeng Li 2025-12-19 9202 9a700d273608de Wanpeng Li 2025-12-19 9203 gran = calc_delta_fair(sysctl_sched_base_slice, se_y_lca); 9a700d273608de Wanpeng Li 2025-12-19 9204 9a700d273608de Wanpeng Li 2025-12-19 9205 /* Calculate fairness gap */ 9a700d273608de Wanpeng Li 2025-12-19 9206 need = 0; 9a700d273608de Wanpeng Li 2025-12-19 9207 if (se_t_lca->vruntime > se_y_lca->vruntime) 9a700d273608de Wanpeng Li 2025-12-19 9208 need = se_t_lca->vruntime - se_y_lca->vruntime; 9a700d273608de Wanpeng Li 2025-12-19 9209 9a700d273608de Wanpeng Li 2025-12-19 9210 /* Base penalty is granularity plus 110% of fairness gap */ 9a700d273608de Wanpeng Li 2025-12-19 9211 penalty = gran; 9a700d273608de Wanpeng Li 2025-12-19 9212 if (need) { 9a700d273608de Wanpeng Li 2025-12-19 @9213 weighted_need = need + need / 10; 9a700d273608de Wanpeng Li 2025-12-19 9214 if (weighted_need > U64_MAX - penalty) 9a700d273608de Wanpeng Li 2025-12-19 9215 weighted_need = U64_MAX - penalty; 9a700d273608de Wanpeng Li 2025-12-19 9216 penalty += weighted_need; 9a700d273608de Wanpeng Li 2025-12-19 9217 } 9a700d273608de Wanpeng Li 2025-12-19 9218 9a700d273608de Wanpeng Li 2025-12-19 9219 /* Apply debounce to reduce ping-pong */ 9a700d273608de Wanpeng Li 2025-12-19 9220 penalty = yield_deboost_apply_debounce(rq, p_target, penalty, need, gran); 9a700d273608de Wanpeng Li 2025-12-19 9221 9a700d273608de Wanpeng Li 2025-12-19 9222 /* Queue-size-based upper bound */ 9a700d273608de Wanpeng Li 2025-12-19 9223 if (h_nr_queued == 2) 9a700d273608de Wanpeng Li 2025-12-19 9224 maxp = gran * 6; 9a700d273608de Wanpeng Li 2025-12-19 9225 else if (h_nr_queued == 3) 9a700d273608de Wanpeng Li 2025-12-19 9226 maxp = gran * 4; 9a700d273608de Wanpeng Li 2025-12-19 9227 else if (h_nr_queued <= 6) 9a700d273608de Wanpeng Li 2025-12-19 9228 maxp = (gran * 5) / 2; 9a700d273608de Wanpeng Li 2025-12-19 9229 else if (h_nr_queued <= 8) 9a700d273608de Wanpeng Li 2025-12-19 9230 maxp = gran * 2; 9a700d273608de Wanpeng Li 2025-12-19 9231 else if (h_nr_queued <= 12) 9a700d273608de Wanpeng Li 2025-12-19 9232 maxp = (gran * 3) / 2; 9a700d273608de Wanpeng Li 2025-12-19 9233 else 9a700d273608de Wanpeng Li 2025-12-19 9234 maxp = gran; 9a700d273608de Wanpeng Li 2025-12-19 9235 9a700d273608de Wanpeng Li 2025-12-19 9236 penalty = clamp(penalty, gran, maxp); 9a700d273608de Wanpeng Li 2025-12-19 9237 9a700d273608de Wanpeng Li 2025-12-19 9238 /* Baseline push when no fairness gap exists */ 9a700d273608de Wanpeng Li 2025-12-19 9239 if (need == 0) { 9a700d273608de Wanpeng Li 2025-12-19 9240 if (h_nr_queued == 3) 9a700d273608de Wanpeng Li 2025-12-19 9241 base = (gran * 15) / 16; 9a700d273608de Wanpeng Li 2025-12-19 9242 else if (h_nr_queued >= 4 && h_nr_queued <= 6) 9a700d273608de Wanpeng Li 2025-12-19 9243 base = (gran * 5) / 8; 9a700d273608de Wanpeng Li 2025-12-19 9244 else if (h_nr_queued >= 7 && h_nr_queued <= 8) 9a700d273608de Wanpeng Li 2025-12-19 9245 base = gran / 2; 9a700d273608de Wanpeng Li 2025-12-19 9246 else if (h_nr_queued >= 9 && h_nr_queued <= 12) 9a700d273608de Wanpeng Li 2025-12-19 9247 base = (gran * 3) / 8; 9a700d273608de Wanpeng Li 2025-12-19 9248 else if (h_nr_queued > 12) 9a700d273608de Wanpeng Li 2025-12-19 9249 base = gran / 4; 9a700d273608de Wanpeng Li 2025-12-19 9250 else 9a700d273608de Wanpeng Li 2025-12-19 9251 base = gran; 9a700d273608de Wanpeng Li 2025-12-19 9252 9a700d273608de Wanpeng Li 2025-12-19 9253 if (penalty < base) 9a700d273608de Wanpeng Li 2025-12-19 9254 penalty = base; 9a700d273608de Wanpeng Li 2025-12-19 9255 } 9a700d273608de Wanpeng Li 2025-12-19 9256 9a700d273608de Wanpeng Li 2025-12-19 9257 return penalty; 9a700d273608de Wanpeng Li 2025-12-19 9258 } 9a700d273608de Wanpeng Li 2025-12-19 9259 -- 0-DAY CI Kernel Test Service https://github.com/intel/lkp-tests/wiki