From owner-freebsd-current@freebsd.org Sat Mar 6 10:47:29 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 0F9A5561707 for ; Sat, 6 Mar 2021 10:47:29 +0000 (UTC) (envelope-from Alexander@leidinger.net) Received: from mailgate.Leidinger.net (mailgate.leidinger.net [IPv6:2a00:1828:2000:313::1:5]) (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 4Dt1Wz4rN0z3jJR for ; Sat, 6 Mar 2021 10:47:27 +0000 (UTC) (envelope-from Alexander@leidinger.net) Received: from outgoing.leidinger.net (p508d5b59.dip0.t-ipconnect.de [80.141.91.89]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-256) server-digest SHA256) (Client did not present a certificate) by mailgate.Leidinger.net (Postfix) with ESMTPSA id 8F2993ACEF for ; Sat, 6 Mar 2021 11:47:18 +0100 (CET) Received: from webmail.leidinger.net (localhost [127.0.0.1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-256) server-digest SHA256) (Client did not present a certificate) by outgoing.leidinger.net (Postfix) with ESMTPS id CCC7A3E63 for ; Sat, 6 Mar 2021 11:46:58 +0100 (CET) Date: Sat, 06 Mar 2021 11:46:58 +0100 Message-ID: <20210306114658.Horde.3TT5LEaEorYtcBz_kyAYJPI@webmail.leidinger.net> From: Alexander Leidinger To: freebsd-current@freebsd.org Subject: Re: Waiting for bufdaemon References: <20210115.201030.1395690536446474720.yasu@utahime.org> <20210116.040323.136067379540977557.yasu@utahime.org> <20210128.050242.1986722766748729591.yasu@utahime.org> <20210305.160311.867123118349124334.yasu@utahime.org> In-Reply-To: Accept-Language: de,en Content-Type: multipart/signed; boundary="=_TFwLucKTOLGmAR3L0ewLpoc"; protocol="application/pgp-signature"; micalg=pgp-sha1 MIME-Version: 1.0 X-Rspamd-Queue-Id: 4Dt1Wz4rN0z3jJR X-Spamd-Bar: ---- X-Spamd-Result: default: False [-4.10 / 15.00]; RCVD_VIA_SMTP_AUTH(0.00)[]; ARC_NA(0.00)[]; R_DKIM_ALLOW(-0.20)[leidinger.net:s=outgoing-alex]; NEURAL_HAM_MEDIUM(-1.00)[-1.000]; FROM_HAS_DN(0.00)[]; TO_MATCH_ENVRCPT_ALL(0.00)[]; R_SPF_ALLOW(-0.20)[+mx]; MIME_GOOD(-0.20)[multipart/signed,text/plain]; TO_DN_NONE(0.00)[]; PREVIOUSLY_DELIVERED(0.00)[freebsd-current@freebsd.org]; RCPT_COUNT_ONE(0.00)[1]; SPAMHAUS_ZRD(0.00)[2a00:1828:2000:313::1:5:from:127.0.2.255]; RCVD_COUNT_THREE(0.00)[3]; DKIM_TRACE(0.00)[leidinger.net:+]; DMARC_POLICY_ALLOW(-0.50)[leidinger.net,quarantine]; NEURAL_HAM_SHORT(-1.00)[-1.000]; NEURAL_HAM_LONG(-1.00)[-1.000]; FROM_EQ_ENVFROM(0.00)[]; MIME_TRACE(0.00)[0:+,1:+,2:~]; RBL_DBL_DONT_QUERY_IPS(0.00)[2a00:1828:2000:313::1:5:from]; ASN(0.00)[asn:34240, ipnet:2a00:1828::/32, country:DE]; RCVD_TLS_ALL(0.00)[]; MAILMAN_DEST(0.00)[freebsd-current]; RECEIVED_SPAMHAUS_PBL(0.00)[80.141.91.89:received] 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: Sat, 06 Mar 2021 10:47:29 -0000 This message is in MIME format and has been PGP signed. --=_TFwLucKTOLGmAR3L0ewLpoc Content-Type: text/plain; charset=utf-8; format=flowed; DelSp=Yes Content-Disposition: inline Content-Transfer-Encoding: quoted-printable Quoting Konstantin Belousov (from Fri, 5 Mar=20=20 2021=2022:43:58 +0200): > On Fri, Mar 05, 2021 at 04:03:11PM +0900, Yasuhiro Kimura wrote: >> 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 CP= U) >> >> Origin=3D"GenuineIntel" Id=3D0x906ed Family=3D0x6 Model=3D0x9e = Stepping=3D13 >> >>=20=20=20=20 >>=20Features=3D0x1783fbff >> >>=20=20=20=20 >>=20Features2=3D0x5eda2203 >> >> AMD Features=3D0x28100800 >> >> AMD Features2=3D0x121 >> >> Structured Extended=20=20 >>=20Features=3D0x842421 >> >> Structured Extended Features3=3D0x30000400 >> >> IA32_ARCH_CAPS=3D0x29 >> >> 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=20=20 >>=20time when we >> > have to effectively disable TSC use in VM. For instance, it=20=20 >>=20was reported >> > (complained) in https://github.com/JuliaLang/julia/issues/38877 th= at >> > 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. > > My belief is that this commit helps more users than it hurts. Namely, > the VMWare and KVM users, which are majority, use fast timecounter, > comparing to the more niche hypervisors like VirtualBox. > > For you, a simple but manual workaround, setting the timecounter to > ACPI (?) or might be HPET, with a loader tunable, should do it. Do you propose this to him as a test if this solves the issue with the=20= =20 intend=20to change the code to use a more suitable TC if VirtualBox is=20= =20 detected? Bye, Alexander. --=20 http://www.Leidinger.net Alexander@Leidinger.net: PGP 0x8F31830F9F2772BF http://www.FreeBSD.org netchild@FreeBSD.org : PGP 0x8F31830F9F2772BF --=_TFwLucKTOLGmAR3L0ewLpoc Content-Type: application/pgp-signature Content-Description: Digitale PGP-Signatur Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iQIcBAABAgAGBQJgQ12iAAoJEBINsJsD+NiG1gsP/jY4NII2uSQjR0fwFY5WtQA9 r0F2DeVJtX+J7m/3xudvHUWIIOr0qlqniXpvIROIf5VZ5heoBtb8yv8O4YBnk6sQ QDUxkra+A1K93O44UYTmkfUeCjXF4ouWs+kUXXc5UMyfisjJQn/BnJnZU/qymWtO 0JQXrLGeSttMV5qdIOLs+coiaaJyqJJ0jqpAH6k2fnUfNYvoGy33UOW649UhnUTV oExPtnNAtz3j02816O0jL5ReuaFSci8aaHHFhaLeWZy88bweF54XSpspoqUr9Czm hcD9Dx1lewYm/g2/2GVNGTmsq3RfkmOBoQr3yvS+AVK4kTCoMv/Zn06OGGlDma+f /d183dFTvQ8+uJGBh0WQBUOYIxdT0BmEq9xLNLmnuB93Q4Fk/s3qaOaavPyKAIh5 LexojEskZl/MFu79ToWeZTchjAXT8FpzP9i/oxnq/zriBg3EM2W6/vdO2DHRk6Ts HcSOAEXUgzb0bFDsfbm9pTg9z2GZmV1wNFBonajsO1NRX8tl3kT51S6wG2PWH9FT /JqEKGA80+NlAQsu9A3jsyOfj3a9zAVQnv2QO0J+YXrPTRhSVUJTMXUd7/AghOkE LIbpPYAVA1o0ZQxs1DwLTY4AmNRuiXyr6b/GdFNNNHnMNljH2Z1iFEZKBSCLxnH5 rmpmibOhm9031buV47R1 =hIWL -----END PGP SIGNATURE----- --=_TFwLucKTOLGmAR3L0ewLpoc--