Date: Tue, 26 Oct 2010 22:57:59 +0300 From: Alexander Motin <mav@FreeBSD.org> To: Takanori Watanabe <takawata@init-main.com> Cc: acpi@freebsd.org, current@freebsd.org, hselasky@c2i.net Subject: Re: Event based scheduling and USB. Message-ID: <4CC732C7.50409@FreeBSD.org> In-Reply-To: <201010261904.o9QJ4iwq089834@sana.init-main.com> References: <201010261904.o9QJ4iwq089834@sana.init-main.com>
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Takanori Watanabe wrote: > I updated my FreeBSD tree on laptop, to the current > as of 18 Oct.2010, it works fine with CPU C3 state enabled, > > I think this is your achievement of event time scheduler, > thanks! > > But when USB driver is enabled, the load average is considerablly > high (0.6 to 1.0) if sysctl oid kern.eventtimer.periodic is set to 0. > Then kern.eventtimer.periodic is set to 1, the load average goes > to 0 quickly as before, but almost never transit to C3. > > Is this behavior expected, or something wrong? > I noticed one of usb host controller device shares HPET irq. > When I implement interrupt filter in uhci driver, the load average > goes to 0 as before. > > > ==== > % vmstat -i > interrupt total rate > irq1: atkbd0 398 2 > irq9: acpi0 408 2 > irq12: psm0 3 0 > irq19: ehci1 37 0 > irq20: hpet0 uhci0 35970 230 > irq22: ehci0 2 0 > irq256: em0 4 0 > irq257: ahci0 1692 10 > Total 38514 246 > === I haven't noticed that issue and it is surely not expected for me. I will try to reproduce it. Most likely you should be able to avoid interrupt sharing using some additional HPET options, described at hpet(4). > BTW, when USB port is enabled C3 transition rate gets lower. > I think it is likely to occur. But how can I supress power > consumption? I can't say about USB, but you may try this patch to optimize some other subsystems: http://people.freebsd.org/~mav/tm6292_idle.patch > It's time to implement powertop for freebsd, isn't it? Surely it is. I was even thinking about possibility to port one from OpenSolaris, but other work distracted me. You may take it, it you wish. -- Alexander Motin
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