From owner-freebsd-current@freebsd.org Wed Apr 7 05:22:50 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 8A47A5CB177 for ; Wed, 7 Apr 2021 05:22:50 +0000 (UTC) (envelope-from phk@critter.freebsd.dk) Received: from mailman.nyi.freebsd.org (mailman.nyi.freebsd.org [IPv6:2610:1c1:1:606c::50:13]) by mx1.freebsd.org (Postfix) with ESMTP id 4FFXpf2dN7z3v5P for ; Wed, 7 Apr 2021 05:22:50 +0000 (UTC) (envelope-from phk@critter.freebsd.dk) Received: by mailman.nyi.freebsd.org (Postfix) id 5A3A55CB212; Wed, 7 Apr 2021 05:22:50 +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 5A05B5CB284 for ; Wed, 7 Apr 2021 05:22:50 +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 4FFXpd2bJRz3vDf for ; Wed, 7 Apr 2021 05:22:48 +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 513B28928B for ; Wed, 7 Apr 2021 05:22:41 +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 1375Mfu0069121 (version=TLSv1.3 cipher=TLS_AES_256_GCM_SHA384 bits=256 verify=NO) for ; Wed, 7 Apr 2021 05:22:41 GMT (envelope-from phk@critter.freebsd.dk) Received: (from phk@localhost) by critter.freebsd.dk (8.16.1/8.16.1/Submit) id 1375Meub069120; Wed, 7 Apr 2021 05:22:40 GMT (envelope-from phk) To: current@freebsd.org Subject: console getty uses 1.5% of CPU From: Poul-Henning Kamp MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-ID: <69118.1617772960.1@critter.freebsd.dk> Content-Transfer-Encoding: quoted-printable Date: Wed, 07 Apr 2021 05:22:40 +0000 Message-ID: <69119.1617772960@critter.freebsd.dk> X-Rspamd-Queue-Id: 4FFXpd2bJRz3vDf 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 [-0.31 / 15.00]; RCVD_TLS_ALL(0.00)[]; ARC_NA(0.00)[]; FREEFALL_USER(0.00)[phk]; FROM_HAS_DN(0.00)[]; RBL_DBL_DONT_QUERY_IPS(0.00)[130.225.244.222:from]; TO_MATCH_ENVRCPT_ALL(0.00)[]; R_SPF_ALLOW(-0.20)[+mx]; MIME_GOOD(-0.10)[text/plain]; TO_DN_NONE(0.00)[]; PREVIOUSLY_DELIVERED(0.00)[current@freebsd.org]; 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_HAM_LONG(-1.00)[-1.000]; NEURAL_HAM_SHORT(-0.31)[-0.313]; 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 05:22:50 -0000 I have two 12.2-R systems where the serial console is attached to a termin= al 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 mod= em-handshake on the DE-9 connector, the CPU usage stops. Anybody else seeing something like this ? -- = 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= .