Date: Mon, 1 Sep 2008 19:21:36 +0200 From: David Naylor <naylor.b.david@gmail.com> To: freebsd-current@freebsd.org Subject: powerd and multicore Message-ID: <200809011921.40737.naylor.b.david@gmail.com>
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--nextPart2707132.nVE3c2aNbb Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable Content-Disposition: inline Hi, The way I understand powerd works by default is that it monitors the CPU us= age=20 (or idleness) and changes the CPU frequency accordingly. The default value= s=20 are >95% idle =3D> decrease frequency; <65% idle =3D> increase frequency. = =20 The problem arises when you have a system with 4 or more 'cores'. In this= =20 case the first CPU can be running flat out but still report an overall=20 idleness of 75% and thus the frequency is not increased even though the fir= st=20 core could easily be stuck, at say 200 when capable of 2400. =20 Should powerd be changed to look at CPU specific usage and adjust according= ly=20 or scale the above defaults according to the number of CPU's. =20 =46urthermore, currently (with core 2) all CPU's are controlled using a sin= gle=20 value however (I think) it is possible to have each CPU running on a=20 different frequency (and at least with some other architectures). Does=20 powerd handle these cases? Regards=20 David P.S. sysctl dev.cpu.0.freq=3D2400 complains about an invalid argument yet=20 adjusts the value accordingly. Is this know or should I file a PR. =20 P.P.S. Should the above be filed as a PR? P.P.P.S. Willing to test patches :-) P.P.P.P.S. This is the last one :-> --nextPart2707132.nVE3c2aNbb Content-Type: application/pgp-signature; name=signature.asc Content-Description: This is a digitally signed message part. -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.4 (FreeBSD) iD8DBQBIvCSkUaaFgP9pFrIRAo+WAJ9kaje0g3R7sMy6GcYmnaiUgM/HiwCeK1rs lP+P3/k/5pJG06CIzmIkDpY= =vgYM -----END PGP SIGNATURE----- --nextPart2707132.nVE3c2aNbb--
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