From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp-fw-80009.amazon.com (smtp-fw-80009.amazon.com [99.78.197.220]) (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 12BF6433BE for ; Tue, 11 Feb 2025 06:41:31 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=99.78.197.220 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1739256093; cv=none; b=R4yg3tRtnGD+qsQKXWhH02rMUUG2wgN2GD0RD/PqiR3nN47DadHPvZqOkwBqXMe2cjdRBZPuDbGBaRW/SsukP7JfvjxeFmPAyEdlWdA7FTkdJ+XaO/uNxqwAkVaaUWjAIIIltG/TkjuPYV5sNEp75CC/1XZq6DugLmu0MeSBGsA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1739256093; c=relaxed/simple; bh=GyCUMivS4VJlWOBBze0/WQTviEBkzALAjaWeS3LlRMw=; h=Subject:From:To:CC:Date:Message-ID:References:In-Reply-To: Content-Type:MIME-Version; b=Ie3NFPbWb/Y6znYBT0vYlcodo7DEB35Px+da625a+AIlrYNBb6yKGCZuBv+k+AY3tfHHuHFxNrZA1+nlqe1lewPmMK83lfEFdMZqAa9vOTsctamzimK/a8GkRpMjyIv5qXYRPqoLAaOF7+Tdxe2N0n8VI3SMnVHPIZLzbHFbE9I= 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=LVV9yuvb; arc=none smtp.client-ip=99.78.197.220 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="LVV9yuvb" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amazon.com; i=@amazon.com; q=dns/txt; s=amazon201209; t=1739256092; x=1770792092; h=from:to:cc:date:message-id:references:in-reply-to: content-transfer-encoding:mime-version:subject; bh=kgEZXMTyNo/0vBWc6Ot4NuneWyKQNfqazBxrkuQHgkY=; b=LVV9yuvbLSJXtSNxedGvG69ZAgXXDPdb8qwcbjxKqzzq/pVmXhxGpszw EuR67s1Oj5m9HQMHRCA0ehpuZz7q/tm7j6Y945iRiB4vAPtL+uwoB3xRk 7ArACBhlSPpAKzlrtY2jYkOA5s0El5IBlf77Hp/t2ivR8OJtZLAul2oAz U=; X-IronPort-AV: E=Sophos;i="6.13,276,1732579200"; d="scan'208";a="171400092" Subject: RE: [PATCH v6 net-next 3/4] net: ena: Add PHC documentation Thread-Topic: [PATCH v6 net-next 3/4] net: ena: Add PHC documentation Received: from pdx4-co-svc-p1-lb2-vlan2.amazon.com (HELO smtpout.prod.us-east-1.prod.farcaster.email.amazon.dev) ([10.25.36.210]) by smtp-border-fw-80009.pdx80.corp.amazon.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 11 Feb 2025 06:41:29 +0000 Received: from EX19MTAEUB002.ant.amazon.com [10.0.17.79:57085] by smtpin.naws.eu-west-1.prod.farcaster.email.amazon.dev [10.0.35.229:2525] with esmtp (Farcaster) id ed518b41-7f26-4356-870c-cd93c9d093c3; Tue, 11 Feb 2025 06:41:28 +0000 (UTC) X-Farcaster-Flow-ID: ed518b41-7f26-4356-870c-cd93c9d093c3 Received: from EX19D002EUA002.ant.amazon.com (10.252.50.7) by EX19MTAEUB002.ant.amazon.com (10.252.51.79) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA) id 15.2.1258.39; Tue, 11 Feb 2025 06:41:28 +0000 Received: from EX19D005EUA002.ant.amazon.com (10.252.50.11) by EX19D002EUA002.ant.amazon.com (10.252.50.7) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA) id 15.2.1544.14; Tue, 11 Feb 2025 06:41:27 +0000 Received: from EX19D005EUA002.ant.amazon.com ([fe80::6aa4:b4a3:92f6:8e9]) by EX19D005EUA002.ant.amazon.com ([fe80::6aa4:b4a3:92f6:8e9%3]) with mapi id 15.02.1258.039; Tue, 11 Feb 2025 06:41:27 +0000 From: "Arinzon, David" To: Jakub Kicinski CC: David Miller , "netdev@vger.kernel.org" , Eric Dumazet , Paolo Abeni , Simon Horman , Richard Cochran , "Woodhouse, David" , "Machulsky, Zorik" , "Matushevsky, Alexander" , "Bshara, Saeed" , "Wilson, Matt" , "Liguori, Anthony" , "Bshara, Nafea" , "Schmeilin, Evgeny" , "Belgazal, Netanel" , "Saidi, Ali" , "Herrenschmidt, Benjamin" , "Kiyanovski, Arthur" , "Dagan, Noam" , "Bernstein, Amit" , "Agroskin, Shay" , "Abboud, Osama" , "Ostrovsky, Evgeny" , "Tabachnik, Ofir" , "Machnikowski, Maciek" , Rahul Rameshbabu , Gal Pressman Thread-Index: AQHbeKGvfULVz4EhOUW1QOSyLY+8YrM8lvgAgAQX1OCAAJwCAIAAY1Ow Date: Tue, 11 Feb 2025 06:41:27 +0000 Message-ID: <796881fe22cc4129b69eadad7ff37a8b@amazon.com> References: <20250206141538.549-1-darinzon@amazon.com> <20250206141538.549-4-darinzon@amazon.com> <20250207165516.2f237586@kernel.org> <01fd0c4d50c7493986d80e22b0506fdf@amazon.com> <20250210164358.11091722@kernel.org> In-Reply-To: <20250210164358.11091722@kernel.org> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 > > You are right in the regard that it is not a network specific functiona= lity. > > Having said that, PHC is a network card capability, making it a network= - > related component rather than purely a timekeeping feature. > > Moreover we failed to find an existing tool which would allow users to = get > valuable feedback of the system's overall health. > > > > Researching its existing support in the kernel we noted that: > > - PHC is embedded in network NIC and is supported by multiple NIC > > vendors in the kernel > > - PHC information is visible through ethtool -T > > - The Linux networking stack uses PHC for timekeeping as well as for pa= cket > timestamping (via SO_TIMESTAMPING). > > Packet timestamping statistics are available through ethtool > > get_ts_stats hook > > > > We have found `ethtool -S` as a suitable location for exposing these > statistics, which are unique to the ENA NIC. > > > > We'd appreciate your thoughts on the matter, is there an alternative to= ol > you can recommend? >=20 > We try to steer folks towards read-only debugfs files for stuff that's no= t > strictly networking related. You also add a custom sysfs file in patch 4,= I > reckon adding stats there may also be a natural place for the user? >=20 > Patch 4 FWIW is lacking slightly in the justification, would be good to c= larify > why it's disabled by default. Single sentence of "why" would be great. Hi Jakub, Thank you for the feedback and the recommendations, we will incorporate the= m in v7.