From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: passt.top; dmarc=none (p=none dis=none) header.from=gibson.dropbear.id.au Authentication-Results: passt.top; dkim=pass (2048-bit key; secure) header.d=gibson.dropbear.id.au header.i=@gibson.dropbear.id.au header.a=rsa-sha256 header.s=202512 header.b=JH5+XUwI; dkim-atps=neutral Received: from mail.ozlabs.org (gandalf.ozlabs.org [150.107.74.76]) by passt.top (Postfix) with ESMTPS id 4F47E5A0624 for ; Tue, 09 Dec 2025 06:13:31 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gibson.dropbear.id.au; s=202512; t=1765257208; bh=kOTB0TfKfRR200POBMf3Ti8M1yB056Xi46KXYC2w2Bk=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=JH5+XUwIj7m03ss8finLUL3VZ9XT4/GHpagp2xqwqAyKH3R1tNW2Zh8EZl1tSvNyE bRusvFjhmPflLG6mL4zi5kgDCh+0o4yCkMYITmvKetfMjdPBaS4H8WaJxnZvQ0M686 ObiIfIhfW2PJuRlUetPjHKcKMLgzvlObUfM4rrUSx/kCGCBOn+5odoFQ9O2BfP797L j9t2sTFx3oj82vAbcpDjC6LOujCwaDIrQ95dyTk5dJJkQU1GZWx1nHVawYbPTE6Hzg BlTqv4ug+th0eaizFDqeZ91RXV01IVcPqdYdjmxxPMf3ov9tqrFQvg2a0PQHAxfnPo VYvpWingd5Rmw== Received: by gandalf.ozlabs.org (Postfix, from userid 1007) id 4dQRp04kqFz4w9R; Tue, 09 Dec 2025 16:13:28 +1100 (AEDT) Date: Tue, 9 Dec 2025 16:05:22 +1100 From: David Gibson To: Stefano Brivio Subject: Re: [PATCH v3 02/10] tcp: Change usage factor of sending buffer in tcp_get_sndbuf() to 75% Message-ID: References: <20251208072024.3884137-1-sbrivio@redhat.com> <20251208072024.3884137-3-sbrivio@redhat.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="hvdsKWeCEtkSrj6K" Content-Disposition: inline In-Reply-To: <20251208072024.3884137-3-sbrivio@redhat.com> Message-ID-Hash: LJDVCCMN7HMSRAP4E5WVFO632TOKV5SX X-Message-ID-Hash: LJDVCCMN7HMSRAP4E5WVFO632TOKV5SX X-MailFrom: dgibson@gandalf.ozlabs.org X-Mailman-Rule-Misses: dmarc-mitigation; no-senders; approved; emergency; loop; banned-address; member-moderation; nonmember-moderation; administrivia; implicit-dest; max-recipients; max-size; news-moderation; no-subject; digests; suspicious-header CC: passt-dev@passt.top, Max Chernoff X-Mailman-Version: 3.3.8 Precedence: list List-Id: Development discussion and patches for passt Archived-At: Archived-At: List-Archive: List-Archive: List-Help: List-Owner: List-Post: List-Subscribe: List-Unsubscribe: --hvdsKWeCEtkSrj6K Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Mon, Dec 08, 2025 at 08:20:15AM +0100, Stefano Brivio wrote: > Now that we have a new clamped_scale() function, which makes it simple > to specify a precise usage factor, change the amount of sending buffer > we want to use at and above 4 MiB: 75% looks perfectly safe. >=20 > Signed-off-by: Stefano Brivio Reviewed-by: David Gibson > --- > tcp.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) >=20 > diff --git a/tcp.c b/tcp.c > index 026546a..37aceed 100644 > --- a/tcp.c > +++ b/tcp.c > @@ -773,7 +773,7 @@ static void tcp_rtt_dst_check(const struct tcp_tap_co= nn *conn, > } > =20 > /** > - * tcp_get_sndbuf() - Get, scale SO_SNDBUF between thresholds (1 to 0.5 = usage) > + * tcp_get_sndbuf() - Get, scale SO_SNDBUF between thresholds (1 to 0.75= usage) > * @conn: Connection pointer > */ > static void tcp_get_sndbuf(struct tcp_tap_conn *conn) > @@ -788,7 +788,7 @@ static void tcp_get_sndbuf(struct tcp_tap_conn *conn) > return; > } > =20 > - v =3D clamped_scale(sndbuf, sndbuf, SNDBUF_SMALL, SNDBUF_BIG, 50); > + v =3D clamped_scale(sndbuf, sndbuf, SNDBUF_SMALL, SNDBUF_BIG, 75); > =20 > SNDBUF_SET(conn, MIN(INT_MAX, v)); > } > --=20 > 2.43.0 >=20 --=20 David Gibson (he or they) | I'll have my music baroque, and my code david AT gibson.dropbear.id.au | minimalist, thank you, not the other way | around. http://www.ozlabs.org/~dgibson --hvdsKWeCEtkSrj6K Content-Type: application/pgp-signature; name=signature.asc -----BEGIN PGP SIGNATURE----- iQIzBAEBCgAdFiEEO+dNsU4E3yXUXRK2zQJF27ox2GcFAmk3rhIACgkQzQJF27ox 2GcUAhAAp1TpVRq0opShSXHQgRIwIzEg+wPEWibzYUsDRRj1qjA5gCcN6jBKa7W4 PiMjjx4iM6PeouaQplSbnYvh8x2H0yHyZjUpuT4Zhxznk0vt/BcybFILYUKzBaPs I05IYfnK6YTM59o5heqMU7NjwOLPswWl9+sF0DAgasaruiCQ7/iXyov7vHN6HIF5 CbWEhoagGt6MfZovmRyvYllXXkZIBIrbTK1IzToTPaizxVGm5qjCgS1ZpZWMYRsB 1VHACIaLL84zUNPc0KRVrNOiGKbUAgbs1NwsBhVnSlX86QJ0v/QTYSZ5ftF6lYH5 3HRyBF8P9bVYrBQIYKWfED+7h2gXXtv4hIC+QzQ5p/i+TPWUhyS38YhEARKY7Dc6 uOudzKAkW7CqFU7fQecURhbaHYQXHl9y7kQ/jA5Y6c3UIBmENNmMU5IHiiwJ9iuV O9n4e5Tntb8kfJzkEHdVO0YADo7hkXAiW1IoCLM988BWBB8ujIvUvZYeB1mmThpL i7Shg4XkPT91nzsWz2+ijzR14EPI7riPU4qbq6yzt3w0o8TiO6nQMSz+uGmM714l Z417Skezuqp0INeeyRJLPZKFW3TwuksL4sHP/C6KeHumZD8+yQukbmw0fy47Nis0 bK8xYIP5dyy72V3+MsgW2/sSCBciccyxTPfZCIxy4zCdKiIpN2Y= =9ZPA -----END PGP SIGNATURE----- --hvdsKWeCEtkSrj6K--