From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) (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 52B60257430 for ; Fri, 28 Feb 2025 10:33:36 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.133.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1740738818; cv=none; b=bzww/D+xJieXJYkGu1GRVaB+K6PWE5pR6A7u7KwTo6hrXlZsXnopkiP67i308asMXEYKyQopdAEizs9eWb482BSR2vEgUEjYOWoXkphuiGneGTAc51U0ZKS+b2JdbmEziYG55HNkk5GO36VJa0oQ4sxfnJqcwLk7ru39i1x5n4Q= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1740738818; c=relaxed/simple; bh=ovZoSm+otbQAllcxqid10BL8xtQRl/XN+WfKwxphflU=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=lD25l78O3KI/WsR6zbn9YWJeonaAK967MB7xnZxaoH2bLp2cghgaE1MWLLPKYwQ3E1+jdKUoKNQ1tx0Snh6EnVx/vmm8I/IkyKlk0EdgpomGdrydgSKlI41gNLZKrpFC0Uo0/8RuLenev8AAJ9DH0MRQ2oF3ZjRUyjg1smZfNao= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=RMpBDuQv; arc=none smtp.client-ip=170.10.133.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="RMpBDuQv" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1740738816; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=ovZoSm+otbQAllcxqid10BL8xtQRl/XN+WfKwxphflU=; b=RMpBDuQvRcnOd9+IsMw977OrQdogK884/IDJalj1Mt385OPtFcXcSQDziv0zbnBvKrglGs b6zh8ACtsh762ts7DjuFXNj8iGX6lEj77VdcP6f0xCY3fSAqRs5qZv4c4DAjKUZkAOnWLY VxysnXYOJlRPiqsawJDQAyKk5j4ROqQ= Received: from mx-prod-mc-02.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-528-ytL_e8psM9igFNE-V-i5vw-1; Fri, 28 Feb 2025 05:33:32 -0500 X-MC-Unique: ytL_e8psM9igFNE-V-i5vw-1 X-Mimecast-MFC-AGG-ID: ytL_e8psM9igFNE-V-i5vw_1740738810 Received: from mx-prod-int-02.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-02.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.15]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-02.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 78B26196E078; Fri, 28 Feb 2025 10:33:29 +0000 (UTC) Received: from redding.lan (unknown [10.45.224.147]) by mx-prod-int-02.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id 8242E19560AE; Fri, 28 Feb 2025 10:33:10 +0000 (UTC) From: Attila Fazekas To: qyousef@layalina.io Cc: dietmar.eggemann@arm.com, frederic@kernel.org, jstultz@google.com, juri.lelli@redhat.com, linux-kernel@vger.kernel.org, mingo@kernel.org, peterz@infradead.org, rostedt@goodmis.org, saravanak@google.com, tglx@linutronix.de, vincent.guittot@linaro.org Subject: Re: [PATCH] Kconfig.hz: Change default HZ to 1000 Date: Fri, 28 Feb 2025 11:33:04 +0100 Message-ID: <20250228103304.302289-1-afazekas@redhat.com> In-Reply-To: <20250210001915.123424-1-qyousef@layalina.io> References: <20250210001915.123424-1-qyousef@layalina.io> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 3.0 on 10.30.177.15 The 250Hz was set as a middle ground. There are still workloads which sensitive to cache misses and to the time spent in ticks. You still can loose ~1% performance with higher Hz, It might not sound much, but if you are running thousands of servers 1% loss can be a high cost. There are many workloads out there where 100Hz is the better choice.