From nobody Wed Sep 17 07:21:18 2025 X-Original-To: net@mlmmj.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mlmmj.nyi.freebsd.org (Postfix) with ESMTP id 4cRVYp6vjkz68PY8 for ; Wed, 17 Sep 2025 07:21:18 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from mxrelay.nyi.freebsd.org (mxrelay.nyi.freebsd.org [IPv6:2610:1c1:1:606c::19:3]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256 client-signature RSA-PSS (4096 bits) client-digest SHA256) (Client CN "mxrelay.nyi.freebsd.org", Issuer "R12" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 4cRVYp4y9Dz3qxg for ; Wed, 17 Sep 2025 07:21:18 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1758093678; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=rB1a1clyNEmNmYuUTXXEnSvujjUOASHU4LbRKhZUTnY=; b=NbiqTzRRHtxOWj73pxs0uo/mALzUPpf/+jVxruLXAhSdQ+j3F5HJPjEBQ5jF/biDxRohld UfNq3zq0l4OG8GZ+k3wS/vxhAxC6GAvIlw3Y2t605TdkQZ9wIdHCJxFenl8Q9Df9FiA+JC IteXzQjxgacDrWRtqeSmSWDivpYBOMsBvXG/TLjYbbmFSbvJLKIdcBB9rlzIlgMop7QXYd jNnuG3EvXYoKPkgKO1zD2QCLQ9ULZpY7K7JOAN4Qzk46eEhD50KwiWbSQY+LXkEP1gUBIA +vFTn4J+8/czD+4hV56+eqBkNHQT1ZSop/yeHQK1N+hsXQZjl8ic1qwQiq3LVw== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1758093678; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=rB1a1clyNEmNmYuUTXXEnSvujjUOASHU4LbRKhZUTnY=; b=iBSoFkOZeLBouvj2Y3IDWq30tjVMV8G/IJzvYqh2iL2JINF3Sdi+wjjs3zPZUTGeGrXfGQ U2LEFyHi89pvUZpCDXj1n0ENYsSPtGOAyVVsZeXEN8MYCdNAG5wvOqqWnqVnJU+OXR1iNz Yq+OMhCL2qLoOveYmKPO5JhYHUsobxVgo/DmoShDFhaMoeP2fR1yWca9td/SFtqCX/ku/F dE7AJ+MsC9ta3dWZ+1U+yx4p+Evsv0me5eIHPfglpR5ySEfwvmqgz2CWlE87b+MuK9a2rt YO1FusmiqI96ceNsWSUboTAX2Tnm/0k5UUHOFPPyTBocdFbHA3bXc1x3vqcAvA== ARC-Seal: i=1; s=dkim; d=freebsd.org; t=1758093678; a=rsa-sha256; cv=none; b=yJlNELXVAiFx9zMoMYuxfjNfo+TMhH79P3D7WFSR1E7IMJIfyVMF7mQTU0eUeukIVhD++5 bhTlUwtjuX8o6rhb7Qac3o4w7LGjnwfs1JfzNtWpsOTRmq6bpsRonPgrWCKS4YP28WCYV/ jsSl4W2uCjNFb8wsPjQ8MtwAZGAVF1YmNCk2yQ71x3r1nxWEKOWtra7iLyX4CKS2HYMiF7 t8MpP+QBOdw4vRRRJ3d4Zb3MJ0+l5+FzeRCKqy3/WfmBJuNEteFuPQYw2lgRtRgkxqAz3J CLIhByRoa4sEW9rpUGH9EVfALfDUcqHa/uFQVBjr2NEF6YaY+/IuQ4gzxAdONg== ARC-Authentication-Results: i=1; mx1.freebsd.org; none Received: from kenobi.freebsd.org (kenobi.freebsd.org [IPv6:2610:1c1:1:606c::50:1d]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (Client did not present a certificate) by mxrelay.nyi.freebsd.org (Postfix) with ESMTPS id 4cRVYp4XRVz1rM for ; Wed, 17 Sep 2025 07:21:18 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from kenobi.freebsd.org ([127.0.1.5]) by kenobi.freebsd.org (8.15.2/8.15.2) with ESMTP id 58H7LItu041813 for ; Wed, 17 Sep 2025 07:21:18 GMT (envelope-from bugzilla-noreply@freebsd.org) Received: (from www@localhost) by kenobi.freebsd.org (8.15.2/8.15.2/Submit) id 58H7LIHM041812 for net@FreeBSD.org; Wed, 17 Sep 2025 07:21:18 GMT (envelope-from bugzilla-noreply@freebsd.org) X-Authentication-Warning: kenobi.freebsd.org: www set sender to bugzilla-noreply@freebsd.org using -f From: bugzilla-noreply@freebsd.org To: net@FreeBSD.org Subject: [Bug 289333] [Feature Request] HFSC overhead calculation Date: Wed, 17 Sep 2025 07:21:18 +0000 X-Bugzilla-Reason: AssignedTo X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: Base System X-Bugzilla-Component: kern X-Bugzilla-Version: Unspecified X-Bugzilla-Keywords: feature X-Bugzilla-Severity: Affects Some People X-Bugzilla-Who: freebsd@danielengel.com X-Bugzilla-Status: New X-Bugzilla-Resolution: X-Bugzilla-Priority: --- X-Bugzilla-Assigned-To: net@FreeBSD.org X-Bugzilla-Flags: X-Bugzilla-Changed-Fields: Message-ID: In-Reply-To: References: Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="UTF-8" X-Bugzilla-URL: https://bugs.freebsd.org/bugzilla/ Auto-Submitted: auto-generated List-Id: Networking and TCP/IP with FreeBSD List-Archive: https://lists.freebsd.org/archives/freebsd-net List-Help: List-Post: List-Subscribe: List-Unsubscribe: Sender: owner-freebsd-net@FreeBSD.org MIME-Version: 1.0 https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=3D289333 --- Comment #6 from Daniel Engel --- (In reply to Oleksandr Kryvulia from comment #5) I don't see a whole lot ofmuch potential in rate-limiting the number of packets. The mix of packet sizes never skews consistently in one direction= or the other. It varies by time of day and current user pattern(s). I will confess to not knowing much about ng_car and netgraph, but it appears to be mainly an API. It's not clear to me how writing a custom solution in user space is any significant improvement over writing a custom solution directly into the kernel.=20=20 So far, all I see are one-dimensional solutions to what is (at least) a 1.5 dimensional problem. The fact that Linux has a direct analog for the featu= re I am asking for implies to me that it can't be readily synthesized from some = set of lower-level features.=20=20 Based on my reading, it seems that HFSC already has almost all of the infrastructure to support a two-dimensional solution. Namely, the x and y coordinates for the service curve(s). It seems that every time that altq_hfsc.c calls m_pktlen(m) -- and there are only a small handful of such calls -- that it would be relatively easy to add a configurable parameter and/or helper function that simulates downstream overhead.=20=20 A couple of additional parameters could even allow HFSC to simulate the eff= ect of the 48-byte ATM boundaries and encoding, although the conventional 15% derating in line throughput probably remains an adequate approximation. --=20 You are receiving this mail because: You are the assignee for the bug.=