From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp-fw-2101.amazon.com (smtp-fw-2101.amazon.com [72.21.196.25]) (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 1F2B5200CB4; Fri, 18 Oct 2024 09:54:36 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=72.21.196.25 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1729245278; cv=none; b=O/EOnaKauK8PDkPjaH96WpP/YUIEkWPRjg2LaLaRZvWu1+cTyLqsfwAkHu5PozCmqiymrIz/xFUhqcuR2CVhjO6sE1ybeKLNxaPYEBlzofrpiEICm5rJh1Uk8VCbFmWc3Sdkt5S0A2Xie1RCaRYkSZhXMmCQD69p3Ha3LIYIIeA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1729245278; c=relaxed/simple; bh=TvnoTTRhmWEdm4EKU+Bod3Liuxl2TsfTwJ29DhNOaLY=; h=Subject:Message-ID:Date:MIME-Version:To:CC:References:From: In-Reply-To:Content-Type; b=VOppINJDoJkPmhchFgUJP7vQrakSgYdwqeSPldZLq1QOWRPA4CALSVCEQxxQOJml/rJumCyYWBYUFH3m4XSInX7Db9C4oBikCoCSs+90sdtu2TOA+ampTaVTLtjJQkiqfhoTwlVBn6ImhygeD8GerG2t3hgUNo2VdHQ5Dre8Dpo= 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 (1024-bit key) header.d=amazon.com header.i=@amazon.com header.b=WK6h/5tV; arc=none smtp.client-ip=72.21.196.25 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 (1024-bit key) header.d=amazon.com header.i=@amazon.com header.b="WK6h/5tV" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amazon.com; i=@amazon.com; q=dns/txt; s=amazon201209; t=1729245277; x=1760781277; h=message-id:date:mime-version:to:cc:references:from: in-reply-to:content-transfer-encoding:subject; bh=iXSmeheKIAOLwXx9bM6D0zvFWASH0Zm7l/lL/GdVuS4=; b=WK6h/5tVhVQUpCeh4FPiWuDq3oYShrcmzUrmbe1H85J1yMijFmMzWS1K TEHm65+xGed6fcJToTl8UfPE6kMG510uwDned/nIVmkf1sFpq5/OizIe6 7yjNYNkyvJ2mjVIk0Jopwlqys8Ritc3pjsE8AgZuVWcDaLqmOYRbKFPdg U=; X-IronPort-AV: E=Sophos;i="6.11,213,1725321600"; d="scan'208";a="436141146" Subject: Re: [PATCH 0/2] [tip: sched/core] sched: Disable PLACE_LAG and RUN_TO_PARITY and move them to sysctl Received: from iad12-co-svc-p1-lb1-vlan3.amazon.com (HELO smtpout.prod.us-west-2.prod.farcaster.email.amazon.dev) ([10.43.8.6]) by smtp-border-fw-2101.iad2.amazon.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 18 Oct 2024 09:54:33 +0000 Received: from EX19MTAEUA002.ant.amazon.com [10.0.10.100:35414] by smtpin.naws.eu-west-1.prod.farcaster.email.amazon.dev [10.0.47.49:2525] with esmtp (Farcaster) id 33701318-bce5-4192-970c-29155082d837; Fri, 18 Oct 2024 09:54:30 +0000 (UTC) X-Farcaster-Flow-ID: 33701318-bce5-4192-970c-29155082d837 Received: from EX19D018EUA004.ant.amazon.com (10.252.50.85) by EX19MTAEUA002.ant.amazon.com (10.252.50.126) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA) id 15.2.1258.34; Fri, 18 Oct 2024 09:54:30 +0000 Received: from [192.168.198.222] (10.106.83.41) by EX19D018EUA004.ant.amazon.com (10.252.50.85) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA) id 15.2.1258.34; Fri, 18 Oct 2024 09:54:30 +0000 Message-ID: Date: Fri, 18 Oct 2024 10:54:19 +0100 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird To: "Prundeanu, Cristian" , Peter Zijlstra CC: "linux-tip-commits@vger.kernel.org" , "linux-kernel@vger.kernel.org" , Ingo Molnar , "x86@kernel.org" , "linux-arm-kernel@lists.infradead.org" , "Doebel, Bjoern" , "Blake, Geoff" , "Saidi, Ali" , "Csoma, Csaba" , "gautham.shenoy@amd.com" References: <20241017052000.99200-1-cpru@amazon.com> <20241017091036.GT16066@noisy.programming.kicks-ass.net> <70D6B66E-B4BC-4A92-9A23-0DADE9B8C3FE@amazon.com> Content-Language: en-US From: "Mohamed Abuelfotoh, Hazem" In-Reply-To: <70D6B66E-B4BC-4A92-9A23-0DADE9B8C3FE@amazon.com> Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 7bit X-ClientProxiedBy: EX19D004EUA004.ant.amazon.com (10.252.50.183) To EX19D018EUA004.ant.amazon.com (10.252.50.85) >> And sysctl is arguably more of an ABI than debugfs, which >> doesn't really sound suitable for workaround. >> >> And I don't see how adding a line to /etc/rc.local is harder than adding >> a line to /etc/sysctl.conf > > Adding a line is equally difficult both ways, you're right. But aren't > most distros better equipped to manage (persist, modify, automate) sysctl > parameters in a standardized manner? > Whereas rc.local seems more "individual need / edge case" oriented. For > instance: changes are done by editing the file, which is poorly scriptable > (unlike the sysctl command, which is a unified interface that reconciles > changes); the load order is also typically late in the boot stage, making > it not an ideal place for settings that affect system processes. > I'd add to what Cristian mentioned is that having these tunables as sysctls will make them more detectable to the end users because checking output of sysctl -a is usually one of the first steps during performance troubleshooting vs checking /sys/kernel/debug/sched/ files so it's easier for people to spot these configurations as sysctls if they notice performance difference after upgrading the kernel. Hazem