From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-dl1-f54.google.com (mail-dl1-f54.google.com [74.125.82.54]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id D1B0343E9EE for ; Wed, 21 Jan 2026 21:15:17 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=74.125.82.54 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769030119; cv=none; b=j0LVuj6441+/P1EHI9Yij1rAf6gI9ldYnYYFF3flF7mJnXe4EjCw2RZoJ6+LFyV69joigRxexlmFTtZtAaj5NVjlNz7ShXPU8p+EoaYkJJyHQUbSLKhfUZeOVyPIVB9alsAU8maSnjY9UHwrrGDTYPB9cEvfG/iVumEVwwCKibc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769030119; c=relaxed/simple; bh=DylRHrAxfykJ18e/Px7mIW+zFbzwCePxQt33PAGkzWs=; h=From:To:Cc:Subject:In-Reply-To:References:Date:Message-ID: MIME-Version:Content-Type; b=PVvKULtg7a5YiNRZ5HgupkcVTQArGZytaTLREVPKgoJr14FdNMKTN87WM2SFbHv2zl48JHbWOZtorKGWJe4mf1wDQHnqaXT1KEHuO+TqnvtA6LavGn6N4u1MWe0fEzEHUb3gbBS9itUBGE6lRdXBPGk4iv9O+0D7PEuF/4AvtzY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=C6lMiCCQ; arc=none smtp.client-ip=74.125.82.54 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="C6lMiCCQ" Received: by mail-dl1-f54.google.com with SMTP id a92af1059eb24-12460a7caa2so466399c88.1 for ; Wed, 21 Jan 2026 13:15:17 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1769030117; x=1769634917; darn=vger.kernel.org; h=mime-version:user-agent:message-id:date:references:in-reply-to :subject:cc:to:from:from:to:cc:subject:date:message-id:reply-to; bh=DylRHrAxfykJ18e/Px7mIW+zFbzwCePxQt33PAGkzWs=; b=C6lMiCCQgVMqPXDYBm9Pw8Kp4HAAmaoAuMQWrp810QYATwjx0Dujq9xZbwZvC4/xxe javC2lKHF0cJWNY7fDj8dIsuIr7OQe9q8SsuH4S6CjrLE6imkEG0NF3GBuY1zsKOcnox QWBb9+zciYhUJ2j0XanIhnMuR/+thhAs3cQXzY+6S3HLvsWUlfXl8HqBjw4GzWfM6NNC FYjYm6TxoSruePPgC5rOGqH1Esdd80KOh/XmM5FD0Pdsua1Dz2UPMvsViIIvq54RbUE8 Z6g9/YIBs/CnkRAYewRdUWsL9hmcp+5ygyP59Q9Glzmp/WOgiD8TBEA6xWhDjFKsV+Im hONQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1769030117; x=1769634917; h=mime-version:user-agent:message-id:date:references:in-reply-to :subject:cc:to:from:x-gm-gg:x-gm-message-state:from:to:cc:subject :date:message-id:reply-to; bh=DylRHrAxfykJ18e/Px7mIW+zFbzwCePxQt33PAGkzWs=; b=OSPKbjFv/N3rBi30HvaJ/09dFeJjtdGktmUgMEYR/FTktNbIsi21jtQIflBarsT9+O pGk92nIKMI+6JdLF89K52F5EwMs5plMoOfjntyriCWwtpC9knMBzDQrTnRAbgvEtGLHh 4GBWpOmR5io8dbvG9FHajlIGzXKqy4rfP2ZY+bLEx0imv3uuZZpJv3JDv7mg23bYK8Ru 1AZweLZDHrF5gw/gQzm4OdOx2g2Nm7laf+sH7pVPD0JIayrAH+uyRsKoVe/vUEyPUuuY vLt71/JgzPC38FxPyt8wGQG1KCE5rkXBdqNQGA5rdmOArurvXlLM+NAmA3VIwdhyR5JV nUWw== X-Forwarded-Encrypted: i=1; AJvYcCXpPFyxANrqWibVhfk6Xc+++NGFPVmlQZVMDPxDZJfIFMysbHEFwtWK3ht1ki/KwyJQ9uSQl5Oq4zbMVtU=@vger.kernel.org X-Gm-Message-State: AOJu0YwFSedbbZqb8QPzspB1f4EsMToka2IYLdl2PxW6hVGhn1O9rFml WlDB8/Rz7Ke5z+QHtXhohisxwLn2/UGWO4x1uzQd549IOiGxmZitD0/u8osJVYotGQ== X-Gm-Gg: AZuq6aJm2m/0XequY7OXmnB3LaOd8MB2Zyr0EbcSTpl7XlgSW1QnJmmWfzYGmwBkMco ta2IhakfF8bZxwgy9arfySrwXZVr+lTz+AoKsgNcb6aMtnCyGWCPlYqizBEq3pTNeXJwOTGK43L 8QzJYib7L6YBqUXjRD2XzKFbHTbdJrhRA7kAWJQahAkO/IQ7YOKC/i90FW+WN6xi5Y4viulbPcs lsXHNZuIqIlIdM6Y0LfdUqK1NAFbxEoNUYtV20Yh0npz+to2TpFGKXHKFq/qPFP+JS62JFv2HXV tuD1W9WY8sU/BK8//6IMgWwMYgPPIyL8n+EokCtRut2Vpi/zLgXpApE5Lhf8gLZeAytFNYawZyG 58Tc3HP+jxVpa6YjSibvrhiRljWOwhDvqfNrY2p4NDyYHkO0PZjfYlfbFqkiGTRoC3NOa1xCNy3 PDz+q7lAQtbLxYFW+o+FbgzHb/G7XY2Z1bYH6DMTkuOuWrU9CP6guYYi8EdaBocWxtxw== X-Received: by 2002:a05:7022:6284:b0:119:e569:f611 with SMTP id a92af1059eb24-1244b30446bmr12140143c88.10.1769030116244; Wed, 21 Jan 2026 13:15:16 -0800 (PST) Received: from bsegall27.localhost ([2a00:79e0:2e5b:a:91aa:5801:8334:42d6]) by smtp.gmail.com with ESMTPSA id a92af1059eb24-1244aefaf0asm24093580c88.9.2026.01.21.13.15.14 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 21 Jan 2026 13:15:15 -0800 (PST) From: Benjamin Segall To: zenghongling Cc: mingo@redhat.com, juri.lelli@redhat.com, dietmar.eggemann@arm.com, rostedt@goodmis.org, mgorman@suse.de, vschneid@redhat.com, linux-kernel@vger.kernel.org, zhongling0719@126.com Subject: Re: [PATCH v1] sched: adjust the layout of the cfs_bandwith structure to save memory In-Reply-To: <20260119032903.11754-1-zenghongling@kylinos.cn> (zenghongling@kylinos.cn's message of "Mon, 19 Jan 2026 11:29:03 +0800") References: <20260119032903.11754-1-zenghongling@kylinos.cn> Date: Wed, 21 Jan 2026 13:15:12 -0800 Message-ID: User-Agent: Gnus/5.13 (Gnus v5.13) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain zenghongling writes: > Using pahole, we can see that there are some padding holes > in the current cfs_bandwith structure. Adjusting the > layout of cfs_bandwith can reduce these holes, > resulting in the size of the structure decreasing > from 240 bytes to 232 bytes. > It is possible to make period_timer access one more cache > line.it is already touching so many cachelines and isn't > that kind of hot path. Something more like: "This make make period_timer access one more cache line, but it is already [...]" And commits generally have a blank line between paragraphs. With that, Reviewed-by: Ben Segall