From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.17]) (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 A93492836B1 for ; Sat, 11 Oct 2025 18:18:24 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.175.65.17 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760206706; cv=none; b=S6xTZtgG4gDit+VImk9W2UzS4qpXEGkcWHMUVoYyOSnpNNw4aucqYAXSSje8zYLjl3z3dX3Jt3ztt7bwcuxWrRrv6qxUGactOiUWUNrvSPN2VWKScV6w3ksMM6saX0NH5ZC3WBABiX0+fpwQlzvqkQFNz80/YqP8x3hbG8jBKng= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760206706; c=relaxed/simple; bh=9oov8ViGgsZaxAZzpTlsnaOcdJ/Jv8NLa7EsoSw2oPE=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=JsV8TTkODWXWFKIKrzZGo3NxMw8hU5p/OWk4qVG3F1HoqgFqWBsu2TcQGUVWw1R9rnOAFP+1s9fHghtr+g8SHhcTCX8Srq+6rXX7gAPQLfCi2R3P+f6W+h6FG6DDQXFxrgsSAi265RFjsNyqSNVDyYiSw0j1kUou9k2jg/TFWas= 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=maHNOTTa; arc=none smtp.client-ip=198.175.65.17 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="maHNOTTa" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1760206705; x=1791742705; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=9oov8ViGgsZaxAZzpTlsnaOcdJ/Jv8NLa7EsoSw2oPE=; b=maHNOTTaUom4zOfjF9aQgzk/EHInefpcQXQBpZ407o2A6QAh7rtx4d1V uIUh04rGM6MxEKMGQGzPbEcwmEUVnQVNQXhq0m60vo8GIlq3nI3UFHh2/ okHOmrxdhoN3uwbNZN5d2mGAMO3ADHunEGtbLYRsJ5ffyJXYwvK9ZYj6n ZqWJDYCygmb5LDln/D3icLbLhH8Zm6QWr4yAgVZQ73wl/I3EgDdp+pIYb aLimiW5HUOhIlD+krR4Rg02sINFyPrZ2h5VJdZ1v01hMqilwa2zgPVcWi tEJ0OmQs9iwf0mBA0kNnJx5l2NSvLy+2FE84H8lwtH6U/4ySfKAnmdVGc Q==; X-CSE-ConnectionGUID: LhZ9XN5ESr6ORNd5zvY9sA== X-CSE-MsgGUID: UBKHEBpdQNSkGD6fqT87jQ== X-IronPort-AV: E=McAfee;i="6800,10657,11531"; a="62339711" X-IronPort-AV: E=Sophos;i="6.17,312,1747724400"; d="scan'208";a="62339711" Received: from orviesa004.jf.intel.com ([10.64.159.144]) by orvoesa109.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 11 Oct 2025 11:18:24 -0700 X-CSE-ConnectionGUID: M/4LVw/6Qg626wVKqENzqw== X-CSE-MsgGUID: hqk2hnIER+q1aJ8R3vcczQ== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.19,221,1754982000"; d="scan'208";a="185487203" Received: from b04f130c83f2.jf.intel.com ([10.165.154.98]) by orviesa004.jf.intel.com with ESMTP; 11 Oct 2025 11:18:24 -0700 From: Tim Chen To: Peter Zijlstra , Ingo Molnar , K Prateek Nayak , "Gautham R . Shenoy" Cc: Tim Chen , Vincent Guittot , 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 , Len Brown , Aubrey Li , Zhao Liu , Chen Yu , Chen Yu , Libo Chen , Adam Li , Tim Chen , linux-kernel@vger.kernel.org Subject: [PATCH 06/19] sched/fair: Assign preferred LLC ID to processes Date: Sat, 11 Oct 2025 11:24:43 -0700 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: 8bit With cache-aware scheduling enabled, each task is assigned a preferred LLC ID. This allows quick identification of the LLC domain where the task prefers to run, similar to numa_preferred_nid in NUMA balancing. Signed-off-by: Tim Chen --- include/linux/sched.h | 1 + init/init_task.c | 3 +++ kernel/sched/fair.c | 7 +++++++ 3 files changed, 11 insertions(+) diff --git a/include/linux/sched.h b/include/linux/sched.h index d7ddb7ce6c4b..8a5e4038cd5c 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -1402,6 +1402,7 @@ struct task_struct { #ifdef CONFIG_SCHED_CACHE struct callback_head cache_work; + int preferred_llc; #endif #ifdef CONFIG_RSEQ diff --git a/init/init_task.c b/init/init_task.c index e557f622bd90..5fffbe766f57 100644 --- a/init/init_task.c +++ b/init/init_task.c @@ -188,6 +188,9 @@ struct task_struct init_task __aligned(L1_CACHE_BYTES) = { .numa_group = NULL, .numa_faults = NULL, #endif +#ifdef CONFIG_SCHED_CACHE + .preferred_llc = -1, +#endif #if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS) .kasan_depth = 1, #endif diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 61c129bde8b6..d6167a029c47 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -1312,6 +1312,7 @@ void account_mm_sched(struct rq *rq, struct task_struct *p, s64 delta_exec) struct mm_struct *mm = p->mm; struct mm_sched *pcpu_sched; unsigned long epoch; + int mm_sched_llc = -1; if (!sched_cache_enabled()) return; @@ -1342,6 +1343,12 @@ void account_mm_sched(struct rq *rq, struct task_struct *p, s64 delta_exec) if (mm->mm_sched_cpu != -1) mm->mm_sched_cpu = -1; } + + if (mm->mm_sched_cpu != -1) + mm_sched_llc = per_cpu(sd_llc_id, mm->mm_sched_cpu); + + if (p->preferred_llc != mm_sched_llc) + p->preferred_llc = mm_sched_llc; } static void task_tick_cache(struct rq *rq, struct task_struct *p) -- 2.32.0