Date: Sun, 14 Dec 2014 23:20:42 +0400 From: Slawa Olhovchenkov <slw@zxy.spb.ru> To: Ian Lepore <ian@freebsd.org> Cc: Poul-Henning Kamp <phk@phk.freebsd.dk>, current@freebsd.org Subject: Re: simple task to speed up booting Message-ID: <20141214192041.GA48237@zxy.spb.ru> In-Reply-To: <1418568731.935.8.camel@freebsd.org> References: <43445.1418553160@critter.freebsd.dk> <1418568731.935.8.camel@freebsd.org>
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On Sun, Dec 14, 2014 at 07:52:11AM -0700, Ian Lepore wrote:
> On Sun, 2014-12-14 at 10:32 +0000, Poul-Henning Kamp wrote:
> > The rotating swirlie ('-/|\') in the loader accounts for a surprisingly
> > large part of our boot time on systems with slow-ish serial consoles.
> >
> > I think right now it takes a step for each 512 byte read, reducing that
> > to once every 64kB or even 1MB would be an improvement with the kind of
> > kernel sizes we have today.
> >
>
> I experimented with that a while ago using the attached patch and was
> disappointed with the results. As I vaguely remember it, a divisor of 8
> looked fine, but had no significant speedup. With a divisor of 32 the
> difference was measureable (only like 1.5 seconds or so faster), but it
> gave the impression that something was wrong, and the overall perception
> was that it was slower rather than faster, despite what a stopwatch
> said.
>
> I was testing at 115kbps, maybe at 9600 it would be significant. I
> don't understand why anything these days is still defaulting to 9600.
> It's the 21st century, but we never got the George Jetson flying cars we
> were promised, and apparently we're never going to break loose from the
> standards set by accoustic-coupled modems.
You not always working with self-owned servers.
Default is 9600,8n1
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