From nobody Fri Apr 07 22:07:13 2023 X-Original-To: freebsd-current@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 4PtXXr1NZvz44FyR for ; Fri, 7 Apr 2023 22:07:24 +0000 (UTC) (envelope-from freebsd-rwg@gndrsh.dnsmgr.net) Received: from gndrsh.dnsmgr.net (br1.CN84in.dnsmgr.net [69.59.192.140]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id 4PtXXq3bL9z4MTM; Fri, 7 Apr 2023 22:07:23 +0000 (UTC) (envelope-from freebsd-rwg@gndrsh.dnsmgr.net) Authentication-Results: mx1.freebsd.org; none Received: from gndrsh.dnsmgr.net (localhost [127.0.0.1]) by gndrsh.dnsmgr.net (8.13.3/8.13.3) with ESMTP id 337M7DaG016130; Fri, 7 Apr 2023 15:07:13 -0700 (PDT) (envelope-from freebsd-rwg@gndrsh.dnsmgr.net) Received: (from freebsd-rwg@localhost) by gndrsh.dnsmgr.net (8.13.3/8.13.3/Submit) id 337M7Dim016129; Fri, 7 Apr 2023 15:07:13 -0700 (PDT) (envelope-from freebsd-rwg) From: "Rodney W. Grimes" Message-Id: <202304072207.337M7Dim016129@gndrsh.dnsmgr.net> Subject: Re: textdumps are too slow In-Reply-To: To: Alan Somers Date: Fri, 7 Apr 2023 15:07:13 -0700 (PDT) CC: Warner Losh , Poul-Henning Kamp , FreeBSD CURRENT X-Mailer: ELM [version 2.4ME+ PL121h (25)] List-Id: Discussions about the use of FreeBSD-current List-Archive: https://lists.freebsd.org/archives/freebsd-current List-Help: List-Post: List-Subscribe: List-Unsubscribe: Sender: owner-freebsd-current@freebsd.org MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset=US-ASCII X-Rspamd-Queue-Id: 4PtXXq3bL9z4MTM X-Spamd-Bar: ---- X-Spamd-Result: default: False [-4.00 / 15.00]; REPLY(-4.00)[]; ASN(0.00)[asn:13868, ipnet:69.59.192.0/19, country:US] X-Rspamd-Pre-Result: action=no action; module=replies; Message is reply to one we originated X-ThisMailContainsUnwantedMimeParts: N > On Fri, Apr 7, 2023 at 12:08?PM Warner Losh wrote: > > > > > > > > On Fri, Apr 7, 2023 at 6:20?AM Poul-Henning Kamp wrote: > >> > >> -------- > >> Alan Somers writes: > >> > On Fri, Apr 7, 2023 at 2:22=E2=80=AFAM Poul-Henning Kamp wrote: > >> > >> > > I would expect them to be limited by the serial console speed before > >> > > the video system speed ? > >> > > >> > That was my first guess, too. But my serial console is 115200 baud, > >> > which is faster than the low performance server grade video card. > >> > >> Ok, that must truly be sucky hardware... > > > > > > That's 10x slower than 1990s era VGA cards then... 115200 is 11k characters a second, > > and FreeBSD on 1990s era VGA cards was in excess of 1MB/s, faster if not a pure ISA > > card... Video hardware that's slower than *THAT* likely indicates a big big problem in > > our video stack. > > > > Warner > > While I'm logged into the video terminal in a normal login session, I > measure about 28M characters/second. So maybe the slow speed is due > to something inefficient in ddb(4). Do you mean to a physically connected vga display and usb/ps2 connected keyboard, or do you mean a serially connected video terminal, or something else like a console created by a BMC? One other thing that could be at issue is a console redirection via serial port, that can make "VGA device" performance appear abismal. -- Rod Grimes rgrimes@freebsd.org