From owner-freebsd-current@freebsd.org Fri Mar 5 07:03:43 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 292D65502F4 for ; Fri, 5 Mar 2021 07:03:43 +0000 (UTC) (envelope-from yasu@utahime.org) Received: from maybe.home.utahime.org (gate.home.utahime.org [183.180.29.210]) (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 4DsJcF6WJ5z3kx3 for ; Fri, 5 Mar 2021 07:03:41 +0000 (UTC) (envelope-from yasu@utahime.org) Received: from eastasia.home.utahime.org (eastasia.home.utahime.org [192.168.174.1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-384) server-digest SHA384) (No client certificate requested) by maybe.home.utahime.org (Postfix) with ESMTPS id DEFEF2D5F6 for ; Fri, 5 Mar 2021 16:03:31 +0900 (JST) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=utahime.org; s=maybe2019112701; t=1614927811; bh=0xqPGweKD0WQcuhXzMSEgpBlO+vBLT6nC1haDebqqHI=; h=Date:To:Subject:From:In-Reply-To:References; b=SByJvhgGVtAbYV7cDCXFSB7DctADIUvaLoBQ9Myi0N2iIimlqNXdQOZKWLIyajteT WjxS3OK9QbD9ZFbm0K/7a8YE16ZjJEJ2fLaWSWJfawTWaOwP/wpoPhjdhHKvkBXodN 1fTC4E9pMoPHRuraXi5pb5Pg/R0SMT3CJyFgFjT4xb/5X5sMfRTxDN5MBMEnejJkm9 uBtj9SyQ2WpQ5cU359poI+y8HMFq3zBVRfz0PEMaDmzzTqVtxoUerKef7QzisxfWGH 0e8+dSPVLozBV3ClBuutnE6DBvw7g+bVanSmsBJnBdC5pNRMsj4ePJ+NgAdOTMWH/F 8I1/IMGIAmJBQ== Received: from localhost (rolling.home.utahime.org [192.168.174.11]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-384) server-digest SHA384) (No client certificate requested) by eastasia.home.utahime.org (Postfix) with ESMTPSA id 174552DABD; Fri, 5 Mar 2021 16:03:29 +0900 (JST) X-Virus-Status: Clean X-Virus-Scanned: clamav-milter 0.103.1 at eastasia.home.utahime.org Date: Fri, 05 Mar 2021 16:03:11 +0900 (JST) Message-Id: <20210305.160311.867123118349124334.yasu@utahime.org> To: freebsd-current@freebsd.org Subject: Re: Waiting for bufdaemon From: Yasuhiro Kimura In-Reply-To: <20210128.050242.1986722766748729591.yasu@utahime.org> References: <20210115.201030.1395690536446474720.yasu@utahime.org> <20210116.040323.136067379540977557.yasu@utahime.org> <20210128.050242.1986722766748729591.yasu@utahime.org> X-Mailer: Mew version 6.8 on Emacs 27.1 Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Rspamd-Queue-Id: 4DsJcF6WJ5z3kx3 X-Spamd-Bar: / Authentication-Results: mx1.freebsd.org; dkim=pass header.d=utahime.org header.s=maybe2019112701 header.b=SByJvhgG; dmarc=none; spf=pass (mx1.freebsd.org: domain of yasu@utahime.org designates 183.180.29.210 as permitted sender) smtp.mailfrom=yasu@utahime.org X-Spamd-Result: default: False [-0.70 / 15.00]; RCVD_VIA_SMTP_AUTH(0.00)[]; MV_CASE(0.50)[]; R_SPF_ALLOW(-0.20)[+a:spf-authorized.utahime.org]; HFILTER_HELO_NORES_A_OR_MX(0.30)[maybe.home.utahime.org]; TO_DN_NONE(0.00)[]; HFILTER_HELO_IP_A(1.00)[maybe.home.utahime.org]; RCVD_COUNT_THREE(0.00)[3]; DKIM_TRACE(0.00)[utahime.org:+]; NEURAL_HAM_SHORT(-1.00)[-0.999]; FROM_EQ_ENVFROM(0.00)[]; MIME_TRACE(0.00)[0:+]; RBL_DBL_DONT_QUERY_IPS(0.00)[183.180.29.210:from]; ASN(0.00)[asn:2519, ipnet:183.180.0.0/16, country:JP]; ARC_NA(0.00)[]; NEURAL_HAM_MEDIUM(-1.00)[-1.000]; R_DKIM_ALLOW(-0.20)[utahime.org:s=maybe2019112701]; FROM_HAS_DN(0.00)[]; TO_MATCH_ENVRCPT_ALL(0.00)[]; NEURAL_HAM_LONG(-1.00)[-1.000]; MIME_GOOD(-0.10)[text/plain]; PREVIOUSLY_DELIVERED(0.00)[freebsd-current@freebsd.org]; DMARC_NA(0.00)[utahime.org]; RCPT_COUNT_ONE(0.00)[1]; SPAMHAUS_ZRD(0.00)[183.180.29.210:from:127.0.2.255]; MID_CONTAINS_FROM(1.00)[]; RCVD_TLS_ALL(0.00)[]; MAILMAN_DEST(0.00)[freebsd-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: Fri, 05 Mar 2021 07:03:43 -0000 Dear src committers, From: Yasuhiro Kimura Subject: Re: Waiting for bufdaemon Date: Thu, 28 Jan 2021 05:02:42 +0900 (JST) >>> I have been experiencing same problem with my 13-CURRENT amd64 >>> VirtualBox VM for about a month. The conditions that the problem >>> happens are unclear and all what I can say is >>> >>> * It happens only after I login in the VM and do something for a >>> while. If I boot the VM and shut it down immediately, it never >>> happens. >>> * When the problem happens, one or more unkillable processes seem to >>> be left. >> >> CPU of my host is not AMD but Intel. According to the >> /var/run/dmesg.boot of VM, information of CPU is as following. >> >> CPU: Intel(R) Core(TM) i7-9700 CPU @ 3.00GHz (3000.09-MHz K8-class CPU) >> Origin="GenuineIntel" Id=0x906ed Family=0x6 Model=0x9e Stepping=13 >> Features=0x1783fbff >> Features2=0x5eda2203 >> AMD Features=0x28100800 >> AMD Features2=0x121 >> Structured Extended Features=0x842421 >> Structured Extended Features3=0x30000400 >> IA32_ARCH_CAPS=0x29 >> TSC: P-state invariant >> >> Just FYI. > > It took for a while to investigate, but according to the result of > bisect following commit is the source of problem in my case. > > ---------------------------------------------------------------------- > commit 84eaf2ccc6a > Author: Konstantin Belousov > Date: Mon Dec 21 19:02:31 2020 +0200 > > x86: stop punishing VMs with low priority for TSC timecounter > > I suspect that virtualization techniques improved from the time when we > have to effectively disable TSC use in VM. For instance, it was reported > (complained) in https://github.com/JuliaLang/julia/issues/38877 that > FreeBSD is groundlessly slow on AWS with some loads. > > Remove the check and start watching for complaints. > > Reviewed by: emaste, grehan > Discussed with: cperciva > Sponsored by: The FreeBSD Foundation > Differential Revision: https://reviews.freebsd.org/D27629 > ---------------------------------------------------------------------- > > I confirmed the problem still happens with 5c325977b11 but reverting > above commit fixes it. Would someone please revert above commit from main, stable/13 and releng/13.0? As I wrote previous mail I submitted this problem to Bugzilla as bug 253087 and added the committer to Cc. But there is no response for 34 days. I confirmed the problem still happens with 37cd6c20dbc of main and 13.0-RC1. Best Regards. --- Yasuhiro Kimura