From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from fra-out-003.esa.eu-central-1.outbound.mail-perimeter.amazon.com (fra-out-003.esa.eu-central-1.outbound.mail-perimeter.amazon.com [3.72.182.33]) (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 59A7E1FDA82 for ; Mon, 22 Sep 2025 12:40:10 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=3.72.182.33 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1758544812; cv=none; b=Oq0UbhEBthxSnCwFAzg9YqLRQAcyAVlq1hGUAv4nVTQm7CO2tCkS1BuMM22Em9unIyAwQcV+2w38Dm1KKjiQF2nsbWu4LY9Tgv1LasLYAmWujOUXvb45qoqZxLyWQSFBvwXR50FyUlq2DzKR+c9pWDajR1xz2eAhnFPDSvof9Lo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1758544812; c=relaxed/simple; bh=nhEwrRFXGLwGgLfeYLcFzpLwUsM4ZuRkkf0SA6e8zN8=; h=From:To:CC:Subject:Date:Message-ID:MIME-Version:Content-Type; b=uiEDbsWtHXQgqyR61I0N5UloHTdnwJw0xjMDlHUhG8hQNpuGQSK0LweKaMbWdlR4oCIxidolHCFekhnr5ruTo1K4nxSDahpd5ywcjNm30rl5nM8Co61igdICq4q9yO7IkLlNOr5qLIzCwLEtiRT85YHqZIIoo85hkFGxsPP4994= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=amazon.com; spf=pass smtp.mailfrom=amazon.com; dkim=pass (2048-bit key) header.d=amazon.com header.i=@amazon.com header.b=DxpWBtra; arc=none smtp.client-ip=3.72.182.33 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=amazon.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=amazon.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=amazon.com header.i=@amazon.com header.b="DxpWBtra" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amazon.com; i=@amazon.com; q=dns/txt; s=amazoncorp2; t=1758544810; x=1790080810; h=from:to:cc:subject:date:message-id:mime-version: content-transfer-encoding; bh=btxZE92atXUsTNqOgDRqwynLwkNYK2ArG6yO/lFWpXg=; b=DxpWBtraFwpOkHGmdUJ7LL6JiLiPXXeDP04TFkWQE1sYmtOnmdAbMlDd d7gJM1RRM4moI1b0woN4Gau8jIUtrD5Q+WZueYOsbYWpHeqgeL5HRGuGt xMge4WIMRpXzhfcy6GJqMc0TE5Nzy7OtKWVJUyurtYLeu5J44IrbK6PQ9 iOadeKONDNVPse4Hdg+BLdsPlTNPTOCeupr7wPPiYdfvNGAdodvWpD6AR 29C8r8eh1AIh5aaRXGklEFm8Gzc3lwWxuhA5DmNO4+Tw2yh2J7zwqKTJY 7ZdzVBEAqaXtOA8IkCpeN63lV3anM0USXSg+1V5lRbMQAPMp/uDbLllQQ g==; X-CSE-ConnectionGUID: HtisJo0TQW2X/5e6UdlDXw== X-CSE-MsgGUID: zKVUMNQgT7embtuxW2yzng== X-IronPort-AV: E=Sophos;i="6.18,285,1751241600"; d="scan'208";a="2482302" Received: from ip-10-6-6-97.eu-central-1.compute.internal (HELO smtpout.naws.eu-central-1.prod.farcaster.email.amazon.dev) ([10.6.6.97]) by internal-fra-out-003.esa.eu-central-1.outbound.mail-perimeter.amazon.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 22 Sep 2025 12:40:00 +0000 Received: from EX19MTAEUC002.ant.amazon.com [54.240.197.228:12495] by smtpin.naws.eu-central-1.prod.farcaster.email.amazon.dev [10.0.23.230:2525] with esmtp (Farcaster) id f2b7bf16-89f4-4539-bd78-4ec8c79bab62; Mon, 22 Sep 2025 12:40:00 +0000 (UTC) X-Farcaster-Flow-ID: f2b7bf16-89f4-4539-bd78-4ec8c79bab62 Received: from EX19D003EUB001.ant.amazon.com (10.252.51.97) by EX19MTAEUC002.ant.amazon.com (10.252.51.245) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA) id 15.2.2562.20; Mon, 22 Sep 2025 12:39:59 +0000 Received: from u5934974a1cdd59.ant.amazon.com (10.146.13.222) by EX19D003EUB001.ant.amazon.com (10.252.51.97) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA) id 15.2.2562.20; Mon, 22 Sep 2025 12:39:52 +0000 From: Fernand Sieber To: , CC: , , , , , , , , , , , , Subject: [PATCH 0/4] sched/fair: Core sched wake up path improvements Date: Mon, 22 Sep 2025 14:39:21 +0200 Message-ID: X-Mailer: git-send-email 2.43.0 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-ClientProxiedBy: EX19D035UWB002.ant.amazon.com (10.13.138.97) To EX19D003EUB001.ant.amazon.com (10.252.51.97) Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit This patch series addresses several issues and improvements in the core scheduling within the fair scheduler's wake-up paths. The overall result is better task placement reducing force idle. The main issues addressed are as follows: Slow path: 1. Fix incorrect cookie matching logic that wrongly discards idle cores 2. Better fallback logic when no cookie matching target is found Fast path: 3. Add cookie checks in wake affine idle to prevent force idle 4. Enhance task selection in select idle sibling to consider cookies Fernand Sieber (4): sched/fair: Fix cookie check on __select_idle_cpu() sched/fair: Still look for the idlest cpu with no matching cookie sched/fair: Add cookie checks on wake idle path sched/fair: Add more core cookie check in wake up fast path kernel/sched/fair.c | 49 ++++++++++++++++++++++++++++++++------------ kernel/sched/sched.h | 41 ++++++++++++++++++++---------------- 2 files changed, 59 insertions(+), 31 deletions(-) -- 2.43.0 Amazon Development Centre (South Africa) (Proprietary) Limited 29 Gogosoa Street, Observatory, Cape Town, Western Cape, 7925, South Africa Registration Number: 2004 / 034463 / 07