From nobody Fri Dec 19 21:09:00 2025 Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.11]) (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 D24952F0C5B for ; Wed, 3 Dec 2025 23:01:30 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.175.65.11 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1764802893; cv=none; b=oh6ql8wRtQTKo8nnK9dUK9t3JsNVUN1SrqTTOLrpZpUDsIKZ+qt9qst5oOs9c5FDd2R9eecOFriCSP4q8iJw0WZIClfw/A2n3lz9QanZX0TndqedBRildmD/ptw2VXSsbXzzCrUFl3ehtEIBnQQqE0gyq5YyFY1waemEa1gZMq0= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1764802893; c=relaxed/simple; bh=ubwbCrnLe+FpFs84fmQJ8NDFPPh85CKovnWcqS4HszM=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=Q4hmeOs7hnwqOE8JDGvxpGVeABvVS45aiDvLk6ZpSrPGuTfn+4YcfZc0AFuBMnvnutRPD41rCA1to3LTp3U/rg4Ky2sVe8bcd4xUTzxW+ljCc0tBYewYHhc60QRARoN5k0NGQJalWwDG5Ur5+u4g9f7uSgwIhh8HrXiFwlORSOs= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com; spf=pass smtp.mailfrom=linux.intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=ngl+EBZ5; arc=none smtp.client-ip=198.175.65.11 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="ngl+EBZ5" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1764802890; x=1796338890; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=ubwbCrnLe+FpFs84fmQJ8NDFPPh85CKovnWcqS4HszM=; b=ngl+EBZ5jKSYuF1GoScWtzUvUawQCvSqX6vXeypzCig51al5M6EFhEW6 6ZPkta/KDGc5tm3cLZAn+Q0r4sAGXevBcvNbEeEF94NWh0Q5o4Qi40yoE 6fENyQt6WsIYC5Biv3AXCHk/Ns+vA3D+5k8K971vxD5ci0G6jwAhua/Ip V4EYKsxzhnY36WL45Wqmck026Nhmf3XpLNt/wYGNgwSMFF7INI6pnMGxW qdO3IW9AZPldmpFj84igpzlIJMlsU2GHA5/5/K1uwnar4bbN3Va12Jz5l CXyXS2But8o6/1q/DIrjmb1ErBv9PahFCMwFzVlsm1m+7SCCYHQiWGEv4 A==; X-CSE-ConnectionGUID: 1JiC3BwvQxSVrDu/qUQ3kA== X-CSE-MsgGUID: lKtqqExhQ5+Xp1L40Y0AnQ== X-IronPort-AV: E=McAfee;i="6800,10657,11631"; a="77136340" X-IronPort-AV: E=Sophos;i="6.20,247,1758610800"; d="scan'208";a="77136340" Received: from fmviesa004.fm.intel.com ([10.60.135.144]) by orvoesa103.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 03 Dec 2025 15:01:30 -0800 X-CSE-ConnectionGUID: lyR4BYigTY+QEoG74KEnKQ== X-CSE-MsgGUID: lE96dcq2TgepzkLPnZNnrg== X-Ironport-Invalid-End-Of-Message: True X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.20,247,1758610800"; d="scan'208";a="199763795" Received: from b04f130c83f2.jf.intel.com ([10.165.154.98]) by fmviesa004.fm.intel.com with ESMTP; 03 Dec 2025 15:01:30 -0800 From: Tim Chen To: Peter Zijlstra , Ingo Molnar , K Prateek Nayak , "Gautham R . Shenoy" , Vincent Guittot Cc: Tim Chen , Juri Lelli , Dietmar Eggemann , Steven Rostedt , Ben Segall , Mel Gorman , Valentin Schneider , Madadi Vineeth Reddy , Hillf Danton , Shrikanth Hegde , Jianyong Wu , Yangyu Chen , Tingyin Duan , Vern Hao , Vern Hao , Len Brown , Aubrey Li , Zhao Liu , Chen Yu , Chen Yu , Adam Li , Aaron Lu , Tim Chen , linux-kernel@vger.kernel.org Subject: [PATCH v2 08/23] sched/cache: Calculate the per runqueue task LLC preference Date: Wed, 3 Dec 2025 15:07:27 -0800 Message-Id: X-Mailer: git-send-email 2.32.0 In-Reply-To: References: Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Calculate the number of tasks' LLC preferences for each runqueue. This statistic is computed during task enqueue and dequeue operations, and is used by the cache-aware load balancing. Co-developed-by: Chen Yu Signed-off-by: Chen Yu Signed-off-by: Tim Chen --- Notes: v1->v2: Split from previous patch for easier review. kernel/sched/fair.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index d46a70a9d9fb..b0e87616e377 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -1231,11 +1231,12 @@ static void account_llc_enqueue(struct rq *rq, stru= ct task_struct *p) return; =20 pref_llc =3D p->preferred_llc; - if (pref_llc < 0) + if (pref_llc < 0 || pref_llc >=3D max_llcs) return; =20 rq->nr_llc_running++; rq->nr_pref_llc_running +=3D (pref_llc =3D=3D task_llc(p)); + rq->nr_pref_llc[pref_llc]++; p->sched_llc_active =3D true; } =20 @@ -1252,11 +1253,12 @@ static void account_llc_dequeue(struct rq *rq, stru= ct task_struct *p) return; =20 pref_llc =3D p->preferred_llc; - if (pref_llc < 0) + if (pref_llc < 0 || pref_llc >=3D max_llcs) return; =20 rq->nr_llc_running--; rq->nr_pref_llc_running -=3D (pref_llc =3D=3D task_llc(p)); + rq->nr_pref_llc[pref_llc]--; p->sched_llc_active =3D false; } =20 --=20 2.32.0