From owner-freebsd-current@freebsd.org Wed Apr 7 05:25:12 2021 Return-Path: Delivered-To: freebsd-current@mailman.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.nyi.freebsd.org (Postfix) with ESMTP id F109B5CB331 for ; Wed, 7 Apr 2021 05:25:12 +0000 (UTC) (envelope-from phk@critter.freebsd.dk) Received: from mailman.nyi.freebsd.org (unknown [127.0.1.3]) by mx1.freebsd.org (Postfix) with ESMTP id 4FFXsN5YsXz3vTV for ; Wed, 7 Apr 2021 05:25:12 +0000 (UTC) (envelope-from phk@critter.freebsd.dk) Received: by mailman.nyi.freebsd.org (Postfix) id BD33C5CB3C2; Wed, 7 Apr 2021 05:25:12 +0000 (UTC) Delivered-To: current@mailman.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.nyi.freebsd.org (Postfix) with ESMTP id BCF435CB330 for ; Wed, 7 Apr 2021 05:25:12 +0000 (UTC) (envelope-from phk@critter.freebsd.dk) Received: from phk.freebsd.dk (phk.freebsd.dk [130.225.244.222]) (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 mx1.freebsd.org (Postfix) with ESMTPS id 4FFXsM6ssTz3vTT for ; Wed, 7 Apr 2021 05:25:11 +0000 (UTC) (envelope-from phk@critter.freebsd.dk) Received: from critter.freebsd.dk (v-critter.freebsd.dk [192.168.55.3]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by phk.freebsd.dk (Postfix) with ESMTPS id 1BF088928B for ; Wed, 7 Apr 2021 05:25:10 +0000 (UTC) Received: from critter.freebsd.dk (localhost [127.0.0.1]) by critter.freebsd.dk (8.16.1/8.16.1) with ESMTPS id 1375P94t069148 (version=TLSv1.3 cipher=TLS_AES_256_GCM_SHA384 bits=256 verify=NO) for ; Wed, 7 Apr 2021 05:25:09 GMT (envelope-from phk@critter.freebsd.dk) Received: (from phk@localhost) by critter.freebsd.dk (8.16.1/8.16.1/Submit) id 1375P9Y0069147; Wed, 7 Apr 2021 05:25:09 GMT (envelope-from phk) cc: current@freebsd.org Subject: Re: console getty uses 1.5% of CPU In-reply-to: <69119.1617772960@critter.freebsd.dk> From: "Poul-Henning Kamp" References: <69119.1617772960@critter.freebsd.dk> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-ID: <69145.1617773109.1@critter.freebsd.dk> Content-Transfer-Encoding: quoted-printable Date: Wed, 07 Apr 2021 05:25:09 +0000 Message-ID: <69146.1617773109@critter.freebsd.dk> X-Rspamd-Queue-Id: 4FFXsM6ssTz3vTT X-Spamd-Bar: ++ Authentication-Results: mx1.freebsd.org; dkim=none; dmarc=none; spf=pass (mx1.freebsd.org: domain of phk@critter.freebsd.dk designates 130.225.244.222 as permitted sender) smtp.mailfrom=phk@critter.freebsd.dk X-Spamd-Result: default: False [2.51 / 15.00]; ARC_NA(0.00)[]; RBL_DBL_DONT_QUERY_IPS(0.00)[130.225.244.222:from]; FREEFALL_USER(0.00)[phk]; FROM_HAS_DN(0.00)[]; R_SPF_ALLOW(-0.20)[+mx:c]; TO_MATCH_ENVRCPT_ALL(0.00)[]; MIME_GOOD(-0.10)[text/plain]; PREVIOUSLY_DELIVERED(0.00)[current@freebsd.org]; TO_DN_NONE(0.00)[]; NEURAL_SPAM_MEDIUM(1.00)[1.000]; RCPT_COUNT_ONE(0.00)[1]; SPAMHAUS_ZRD(0.00)[130.225.244.222:from:127.0.2.255]; RCVD_COUNT_THREE(0.00)[3]; DMARC_NA(0.00)[freebsd.dk]; NEURAL_SPAM_SHORT(0.51)[0.513]; NEURAL_HAM_LONG(-1.00)[-1.000]; RCVD_TLS_ALL(0.00)[]; MISSING_TO(2.00)[]; FORGED_SENDER(0.30)[phk@phk.freebsd.dk,phk@critter.freebsd.dk]; R_DKIM_NA(0.00)[]; MIME_TRACE(0.00)[0:+]; ASN(0.00)[asn:1835, ipnet:130.225.0.0/16, country:EU]; FROM_NEQ_ENVFROM(0.00)[phk@phk.freebsd.dk,phk@critter.freebsd.dk]; MAILMAN_DEST(0.00)[current] X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 07 Apr 2021 05:25:13 -0000 -------- Poul-Henning Kamp writes: > I have two 12.2-R systems where the serial console is attached to a term= inal server. > > When there are no TCP connections to the terminal server, getty soaks up= 1.5% of the > CPU in the kernel (sleeping in "ttyin"), ktrace shows no system calls. > > When a TCP connection is made to the terminal server, which raises the m= odem-handshake > on the DE-9 connector, the CPU usage stops. > > Anybody else seeing something like this ? Just checked, also happens on a similar box running 13.0-ALPHA3 -- = Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 phk@FreeBSD.ORG | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe = Never attribute to malice what can adequately be explained by incompetence= .