Date: Sat, 21 Jan 2012 14:20:40 +0100 From: Martin Sugioarto <martin@sugioarto.com> To: Alexander Motin <mav@FreeBSD.org> Cc: FreeBSD-STABLE Mailing List <freebsd-stable@freebsd.org> Subject: Re: Timekeeping in stable/9 Message-ID: <20120121142040.1805e2ed@zelda.sugioarto.com> In-Reply-To: <4F1AAFFD.7070303@FreeBSD.org> References: <20120118075049.289954e8@zelda.sugioarto.com> <mailpost.1327137575.1997238.49263.mailing.freebsd.stable@FreeBSD.cs.nctu.edu.tw> <4F1AAFFD.7070303@FreeBSD.org>
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--Sig_/wodxOEI3Z8kWpGqu6x6TCIC Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: quoted-printable Am Sat, 21 Jan 2012 14:30:53 +0200 schrieb Alexander Motin <mav@FreeBSD.org>: Hi Alexander, > I am not using VirtualBox right now, so I'll need to setup it to test=20 > this. Meanwhile you could try to experiment with switching to > different timecounters and eventtimers. May be some change in 9.0 > changed default timecounter for you, causing the problem. I think we have a misunderstanding here. The host (FreeBSD 9.0R) works fine. The time is being updated under heavy load without problems. I already said that this seems to be an application problem and this email(s) should be rather seen by the VBox maintainer. The problem is that VBox seems to stop working properly when you put heavy CPU load on the host. It even does not keep the clock up-to-date. I can desync the guest clock to -1 minute in a few seconds, just by running "openssl speed -multi 20". > timecounter wrap should be the main cause of time drift (if > timecounter hardware is emulated correctly at all). Different > timecounters have different wrap periods that can be calculated by > dividing kern.timecounter.tc.X.mask on > kern.timecounter.tc.X.frequency. In my case there are: 300s for HPET, > 5s for ACPI-fast, 2s for TSC and 55ms for i8254. If system won't get > timer interrupts within half of that time -- time will drift. Start > from looking what you are using and how good it is in your case. This is my current timecounter setting: kern.timecounter.choice: TSC-low(1000) HPET(950) i8254(0) ACPI-fast(900) dummy(-1000000) kern.timecounter.hardware: TSC-low kern.timecounter.tc.ACPI-fast.mask: 16777215 kern.timecounter.tc.ACPI-fast.counter: 10400371 kern.timecounter.tc.ACPI-fast.frequency: 3579545 kern.timecounter.tc.ACPI-fast.quality: 900 kern.timecounter.tc.i8254.mask: 65535 kern.timecounter.tc.i8254.counter: 41849 kern.timecounter.tc.i8254.frequency: 1193182 kern.timecounter.tc.i8254.quality: 0 kern.timecounter.tc.HPET.mask: 4294967295 kern.timecounter.tc.HPET.counter: 3255982446 kern.timecounter.tc.HPET.frequency: 14318180 kern.timecounter.tc.HPET.quality: 950 kern.timecounter.tc.TSC-low.mask: 4294967295 kern.timecounter.tc.TSC-low.counter: 1587561917 kern.timecounter.tc.TSC-low.frequency: 8593928 kern.timecounter.tc.TSC-low.quality: 1000 kern.timecounter.smp_tsc: 1 kern.timecounter.invariant_tsc: 1 I can try other timer counter settings, if you think it will improve responsivity inside VBox guest. -- Martin --Sig_/wodxOEI3Z8kWpGqu6x6TCIC Content-Type: application/pgp-signature; name=signature.asc Content-Disposition: attachment; filename=signature.asc -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.18 (FreeBSD) iQIcBAEBAgAGBQJPGruzAAoJEF8wvLx/5p/7wfIP/0kJOte5etn1PMUjP0OcdC13 UyDooq76PAloAPn7eFbnPX52YQgOzlGzg6gAtX5ut6xHhgbtoWJFSLk0o4Edhz/O npZ9wZDJ5vt5BvRa1eyTMxhxfgN91rLiPVkPe5VHQFUmezAzHSgX/i9LjAb2VQAh kJMIfoG+MKAo/qaoR7+8lNSn79ZPJJmKYOnpwn2RvBQ7x9KyMZUR62v8TX0cpwKL XEROvvMj5S9B4ikSpBwyPnFS473AOmx+LKL5/vosYxpT8HBxXfwuUp/iFz1G7BMG PI2ybdwzgqnzdneHV3eM26VeuvNmi4C0XvcqEimqkMsRtl12bz+s80flNcs4Y+s/ 09WTDS13eTigGHsprmeAjkqsYcq4HtuLOpFnV5bOqczp5cLMFYaBKnKMAs+P4683 rkPYfj/bxp7zQHASCEQs9cb/mMRPBtlluKxL46d06GpnOb+DIPvsKzOS5o3PX0sO DYYZUR6BcRNwAd5ExI3s5QE/Sa2FQsO0lSaYaUrfPhrhbBwtw8ZEiUEcFTY8PXMX xrahI2IDjnzN63KhTJCBUp5yU6wgelyJAsW+cpsEqIE0T34EVp9DVm8YImkvOT7u rPEXHmakkDcgAfczvtnyGUqNQPhPp2cF/mprv6Wh0X/GkYgkJvKW120f8PS/jBUC QTEwwV1Qfb24765zMaoY =nTKx -----END PGP SIGNATURE----- --Sig_/wodxOEI3Z8kWpGqu6x6TCIC--
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