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 7498E1A76BB for ; Thu, 5 Feb 2026 21:25:47 +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=1770326748; cv=none; b=smAsgTJdwNFTtoX/xqLBJSOoI3ZeUkBkcN9OTpI//av4kW599XZCnr00Jmk7puDbkt+PwmFTqO8lzwy3pRIkj8LtZ+TnOyGfFIsJi7Zpr1bPpaHq080ujT0661TRl67rQG1ItzkSqWopQcVj0HGVrb3Ckj50WpEAU2IWf8IgXzM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770326748; c=relaxed/simple; bh=T+xsP/3fml7WhRkdmRz4pmlMJefBxdAQn+mBHHSbBCE=; h=From:To:Cc:Subject:Date:Message-Id:MIME-Version; b=hqy96yKCdUwsci+QifxjIuFJJm5GbmQejLzU47p2lwGSKDXHln/txpYdHtPrB6Wp5zZnnc4A4WGFdN6xZtYByDi7bSNlmQozJE58QCQ5/6dOUQj1/tcCyeK6bzebvCW8o4c0oluarPaBTYAobkjVjHsdEJjnpqvTcRnTf/nUwA0= 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=c5Q7ptp0; 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="c5Q7ptp0" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1770326748; x=1801862748; h=from:to:cc:subject:date:message-id:mime-version: content-transfer-encoding; bh=T+xsP/3fml7WhRkdmRz4pmlMJefBxdAQn+mBHHSbBCE=; b=c5Q7ptp0AbyZtQVjXcQsdHE2mjzwUBRCLiJO2iI1IpQGkEtv/HVUJ0Pp PnzocMFK/LkUJJyOYXtzGUU2HI71WUvNbB4B3ZIHghYk0+O1y4qhLnDE/ LckqlFwbb8jAHLdyRqdHMnikR0sRfTVSlhyYHTtQXDdV/3Hv+kv1RQdUw VFVthFBgwSwK+kApTJ8NVBPoIvk5QNiV7xbwGRmA/TtuxAbLQA2CEMpgw Wi8vRoXzctxWt2xyjwL05piAtfi3H7l+WT0f2SBhl5fRfh5AEHMWGZDnd 2CpZw83WDBSWTZM38dgh+p/1HPfxaXiFiqCqgUY5R0oyGfXV44kDSMgBx A==; X-CSE-ConnectionGUID: oLuJVnO5QQy1CRk/vJw3NA== X-CSE-MsgGUID: GenmAsoTTs6rv3/xaWCZNA== X-IronPort-AV: E=McAfee;i="6800,10657,11692"; a="71529145" X-IronPort-AV: E=Sophos;i="6.21,275,1763452800"; d="scan'208";a="71529145" Received: from fmviesa005.fm.intel.com ([10.60.135.145]) by orvoesa109.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 05 Feb 2026 13:25:47 -0800 X-CSE-ConnectionGUID: MuBJFfPfSliQwSQUQFcEvg== X-CSE-MsgGUID: P/8uF3qkR+GRiVPVek+pRA== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.21,275,1763452800"; d="scan'208";a="215175676" Received: from b04f130c83f2.jf.intel.com ([10.165.154.98]) by fmviesa005.fm.intel.com with ESMTP; 05 Feb 2026 13:25:46 -0800 From: Tim Chen To: stable@vger.kernel.org Cc: Tim Chen , Peter Zijlstra , Ingo Molnar , Chen Yu , Doug Nelson , Mohini Narkhede , Vincent Guittot , K Prateek Nayak , Srikar Dronamraju , nathan@kernel.org Subject: [PATCH 6.18 0/2] Acquire sched_balance_running only when needed Date: Thu, 5 Feb 2026 13:31:55 -0800 Message-Id: X-Mailer: git-send-email 2.32.0 Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Balancing sched domains NUMA and above are serialized. Currently, multiple sched group leader directly under NUMA domain could attempt to acquire the global sched_balance_running flag via cmpxchg() before checking whether load balancing is due. Fix unnecessary sched_balance_running acquisition and also put newidle balance properly in serialization. This improves performance for OLTP workload on large core count machines. These patches have been merged upstream. Thanks. Tim Peter Zijlstra (1): sched/fair: Have SD_SERIALIZE affect newidle balancing Tim Chen (1): sched/fair: Skip sched_balance_running cmpxchg when balance is not due kernel/sched/fair.c | 54 +++++++++++++++++++++++---------------------- 1 file changed, 28 insertions(+), 26 deletions(-) -- 2.32.0