Skip site navigation (1)Skip section navigation (2)
Date:      Thu, 21 Sep 2000 16:18:23 -0700
From:      Mike Smith <msmith@freebsd.org>
To:        Warner Losh <imp@village.org>
Cc:        current@FreeBSD.ORG
Subject:   Re: new idle_proc() makes my laptop very hot 
Message-ID:  <200009212318.QAA92785@mass.osd.bsdi.com>
In-Reply-To: Your message of "Thu, 21 Sep 2000 17:10:51 MDT." <200009212310.RAA62949@harmony.village.org> 

next in thread | previous in thread | raw e-mail | index | archive | help
> In message <200009212303.QAA62850@mass.osd.bsdi.com> Mike Smith writes:
> : If I remember from a discussion with John Baldwin, the reason we don't do 
> : this (yet) is that HLT only wakes up when you take an interrupt, and 
> : there are cases where we can't guarantee that we'll take an interrupt in 
> : order to get us out of the HLT.
> 
> I thought that's what the timer interrupts were for...  We can't
> guarantee that we'll get one?  That seems very serious to me.

Think about the MP environment.  There's one timer interrupt, and more 
than one CPU.  In the UP case, you could probably rely on HLT to DTRT 
though; this is an optimisation that will probably come back shortly.

> : HLT helps a lot, yes, but the thermal management code is responsible for 
> : running the system fan(s) in ACPI mode as well as throttling the CPU.  In 
> : some cases, that's a real issue (eg. I'm building the world now and 
> : extremely worried about how hot this system is because I forgot to turn 
> : ACPI off first. 8)
> 
> Ah.  I don't have a system fan :-)

Some of us need them. 8)

-- 
... every activity meets with opposition, everyone who acts has his
rivals and unfortunately opponents also.  But not because people want
to be opponents, rather because the tasks and relationships force
people to take different points of view.  [Dr. Fritz Todt]




To Unsubscribe: send mail to majordomo@FreeBSD.org
with "unsubscribe freebsd-current" in the body of the message




Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?200009212318.QAA92785>