From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mails.dpdk.org (mails.dpdk.org [217.70.189.124]) by inbox.dpdk.org (Postfix) with ESMTP id C5C9A459D7 for ; Fri, 20 Sep 2024 17:11:37 +0200 (CEST) Received: from mails.dpdk.org (localhost [127.0.0.1]) by mails.dpdk.org (Postfix) with ESMTP id B326143459; Fri, 20 Sep 2024 17:11:37 +0200 (CEST) Received: from mail-pl1-f182.google.com (mail-pl1-f182.google.com [209.85.214.182]) by mails.dpdk.org (Postfix) with ESMTP id A5B554067E for ; Fri, 20 Sep 2024 17:11:36 +0200 (CEST) Received: by mail-pl1-f182.google.com with SMTP id d9443c01a7336-206e614953aso22548275ad.1 for ; Fri, 20 Sep 2024 08:11:36 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1726845096; x=1727449896; darn=dpdk.org; h=content-transfer-encoding:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:from:to:cc:subject:date :message-id:reply-to; bh=QUMNWZq/+eWvV5mIqr6fZFJZsGIWS6yte5XHdy2SKa4=; b=h2VujlVTWbFZkHUrnWd7yqhWvtbRm9nQnftc5/sUAw8GPaZiTPiM7qKuEqFINvFGt0 lLv2THgQRmeA5aEjQAGDcAXu98nL/s48zvXfI96hXIhR+ZDmu6eRluJ4H26VXj4vO/5F D2xIyCHUd/u0jMBLpjHzG0wtTGrnQ3TEZQ5laSryWGd9g3D0ZZwYriTfkiN4LorPMJDp zFX9z8YKLVD0P6J2lKIJLDjWglJFEhCALIXChM53crR2evpfOiy7mKfhBTvnH2dmgqCI fUKxFuhoTx8Var/qy7eHs7/lP87v3YrEmXqvb0/nNqVVPosg/mdJLmaJuCrqSLdLGJCP 3LSQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1726845096; x=1727449896; h=content-transfer-encoding:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=QUMNWZq/+eWvV5mIqr6fZFJZsGIWS6yte5XHdy2SKa4=; b=K3TF6cM8/TS1wNblsD3R7EU4efEQTExWxSykTMiZH2tTtUd0bmOfq1vLlR+ulfGl0c sPEKugRK21E2PkFrRvl2zcwPD5VLpcvxLa62yje3Sw39AKJbYc3FG214AhvnKHht1gEM QAGUdqt+q83a4hyABOPY9Fg94wfvspb3c6O+4akQs32Gn47PEaRoZj5/CK+Im8rPD628 dErRJAMA5IeEwmvMcP2iCMI5WtimQJBZJi2GGv1nFUs1yvoWZvFNFfouHu8MH2a4Zf+s G8K1vxaMUotBosg9wMPGK1nhe7JSmNrsu8GpvYkgErpyDxD+goXcsMY6HICNVk6FcKWe sn1A== X-Forwarded-Encrypted: i=1; AJvYcCVAval3VfAeZoHoZf3R5mxQAPMo4OuuuOXyejlZ7j0d+lIsXLDdZw42ND8enb6lKyqavtRsAw==@dpdk.org X-Gm-Message-State: AOJu0Yz3bRy+Fhd+TGPI0gjwSyWeaLPgaJhUZ6s3Iodh8Z3mLDbfO5Dw ZgwB8KtEd7aJH7X2iX6eMQyI4dpjSExpZMqx8vs0GL3p4c4hg4srION0ugwkWL1U69Z2V+FbcrE GCMsmlHUr29IIUfbmuhlhZaqbEkR4iAc3 X-Google-Smtp-Source: AGHT+IGJ3sWc8ZPskuxR07BLQaKqoEscLUW+tVZnFIRuFB6QIXmgggGC1ctlcUKGKL0jVsMt/QcYFZl/4cqf6HBnV6g= X-Received: by 2002:a17:902:db12:b0:207:5cfc:504a with SMTP id d9443c01a7336-208d836cb41mr54446135ad.4.1726845095748; Fri, 20 Sep 2024 08:11:35 -0700 (PDT) MIME-Version: 1.0 References: <20240919152148.45a19343@hermes.local> <20240920073657.342332a7@hermes.local> In-Reply-To: <20240920073657.342332a7@hermes.local> From: Isaac Boukris Date: Fri, 20 Sep 2024 18:11:24 +0300 Message-ID: Subject: Re: Accuracy of rte_get_tsc_hz() compared to linux To: Stephen Hemminger Cc: David Marchand , users@dpdk.org Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-BeenThere: users@dpdk.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: DPDK usage discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: users-bounces@dpdk.org On Fri, Sep 20, 2024 at 5:36=E2=80=AFPM Stephen Hemminger wrote: > > On Fri, 20 Sep 2024 09:26:05 +0200 > David Marchand wrote: > > > On Fri, Sep 20, 2024 at 12:22=E2=80=AFAM Stephen Hemminger > > wrote: > > > Sigh. exposing tsc frequency through sysfs is a Redhat extension > > > that never got merged upstream. > > > > Counter sight :-). > > > > Not sure where this assertion comes from. > > I see no trace of this downstream: RH policy is "upstream first". > > > > I missed the driver stuff in original mail and assumed that > since it wasn't in upstream (or Debian) that it came from Redhat. Sorry. > > It would be good if kernel exposed it, and there was a proposal > to do that, but it seemed to die from "no one should ever need or care ab= out that" > > https://lwn.net/Articles/388263/ > Too bad it wasn't merged, the tsc_mult and tsc_shift would have been even better than tsc_khz itself, we could've implemented an even more efficient cycles_ts_ns.I don't get what is the point of making rdtsc available in userspace without this.