From nobody Tue Jun 22 19:04:34 2021 X-Original-To: bugs@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 C5EDF5D429B for ; Tue, 22 Jun 2021 19:04:34 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from mxrelay.nyi.freebsd.org (mxrelay.nyi.freebsd.org [IPv6:2610:1c1:1:606c::19:3]) (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-signature RSA-PSS (4096 bits) client-digest SHA256) (Client CN "mxrelay.nyi.freebsd.org", Issuer "R3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 4G8bRk59Zbz3pNK for ; Tue, 22 Jun 2021 19:04:34 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from kenobi.freebsd.org (kenobi.freebsd.org [IPv6:2610:1c1:1:606c::50:1d]) (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 mxrelay.nyi.freebsd.org (Postfix) with ESMTPS id 996D8161F2 for ; Tue, 22 Jun 2021 19:04:34 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from kenobi.freebsd.org ([127.0.1.5]) by kenobi.freebsd.org (8.15.2/8.15.2) with ESMTP id 15MJ4YCq041912 for ; Tue, 22 Jun 2021 19:04:34 GMT (envelope-from bugzilla-noreply@freebsd.org) Received: (from www@localhost) by kenobi.freebsd.org (8.15.2/8.15.2/Submit) id 15MJ4Y2c041911 for bugs@FreeBSD.org; Tue, 22 Jun 2021 19:04:34 GMT (envelope-from bugzilla-noreply@freebsd.org) X-Authentication-Warning: kenobi.freebsd.org: www set sender to bugzilla-noreply@freebsd.org using -f From: bugzilla-noreply@freebsd.org To: bugs@FreeBSD.org Subject: [Bug 256781] TSC-low timecounter lags on EC2 nitro instances Date: Tue, 22 Jun 2021 19:04:34 +0000 X-Bugzilla-Reason: AssignedTo X-Bugzilla-Type: new X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: Base System X-Bugzilla-Component: kern X-Bugzilla-Version: 13.0-RELEASE X-Bugzilla-Keywords: X-Bugzilla-Severity: Affects Only Me X-Bugzilla-Who: martin.stoyanov@vertalo.com X-Bugzilla-Status: New X-Bugzilla-Resolution: X-Bugzilla-Priority: --- X-Bugzilla-Assigned-To: bugs@FreeBSD.org X-Bugzilla-Flags: X-Bugzilla-Changed-Fields: bug_id short_desc product version rep_platform op_sys bug_status bug_severity priority component assigned_to reporter Message-ID: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Bugzilla-URL: https://bugs.freebsd.org/bugzilla/ Auto-Submitted: auto-generated List-Id: Bug reports List-Archive: https://lists.freebsd.org/archives/freebsd-bugs List-Help: List-Post: List-Subscribe: List-Unsubscribe: Sender: owner-freebsd-bugs@freebsd.org MIME-Version: 1.0 X-ThisMailContainsUnwantedMimeParts: N https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=3D256781 Bug ID: 256781 Summary: TSC-low timecounter lags on EC2 nitro instances Product: Base System Version: 13.0-RELEASE Hardware: amd64 OS: Any Status: New Severity: Affects Only Me Priority: --- Component: kern Assignee: bugs@FreeBSD.org Reporter: martin.stoyanov@vertalo.com I am trying to use the latest FreeBSD 13 Release AMIs on EC2 and by default they start up with: kern.timecounter.hardware: TSC-low which results in a very slow clock. I did these rudimentary tests, hopefully demonstrating the problem. (all date commands were executed one minute apart after switching the timecounter. root@buildbot_master: # sysctl kern.timecounter.hardware=3Di8254 kern.timecounter.hardware: TSC-low -> i8254 root@buildbot_master: # date Tue Jun 22 18:22:45 UTC 2021 root@buildbot_master: # date Tue Jun 22 18:23:46 UTC 2021 root@buildbot_master: # sysctl kern.timecounter.hardware=3DACPI-fast kern.timecounter.hardware: i8254 -> ACPI-fast root@buildbot_master: # date Tue Jun 22 18:24:46 UTC 2021 root@buildbot_master: # date Tue Jun 22 18:25:45 UTC 2021 root@buildbot_master: # sysctl kern.timecounter.hardware=3DHPET kern.timecounter.hardware: ACPI-fast -> HPET root@buildbot_master: # date Tue Jun 22 18:26:45 UTC 2021 root@buildbot_master: # date Tue Jun 22 18:27:45 UTC 2021 root@buildbot_master:/var/service-dir # sysctl kern.timecounter.hardware=3DTSC-low kern.timecounter.hardware: HPET -> TSC-low root@buildbot_master: # date Tue Jun 22 18:28:16 UTC 2021 root@buildbot_master: # date Tue Jun 22 18:28:43 UTC 2021 This is the uname of the machine and if you need any additional info I'd be happy to provide it: root@buildbot_master: # uname -a FreeBSD buildbot_master 13.0-RELEASE-p1 FreeBSD 13.0-RELEASE-p1 #0: Wed May= 26 22:15:09 UTC 2021=20=20=20=20 root@amd64-builder.daemonology.net:/usr/obj/usr/src/amd64.amd64/sys/GENERIC= =20 amd64 --=20 You are receiving this mail because: You are the assignee for the bug.=