Date: Sat, 5 Mar 2011 13:17:18 +0000 From: Alexander Best <arundel@freebsd.org> To: "illoai@gmail.com" <illoai@gmail.com> Cc: David Demelier <demelier.david@gmail.com>, freebsd-questions@freebsd.org Subject: Re: FreeBSD kernel init slower than linux Message-ID: <20110305131718.GA57122@freebsd.org> In-Reply-To: <AANLkTimOnkSZZ_jgnxVPtLCqm=uQzoF_GKpReqsuvZ7w@mail.gmail.com> References: <4D716372.2050606@gmail.com> <AANLkTimOnkSZZ_jgnxVPtLCqm=uQzoF_GKpReqsuvZ7w@mail.gmail.com>
index | next in thread | previous in thread | raw e-mail
On Fri Mar 4 11, illoai@gmail.com wrote:
> On 4 March 2011 17:10, David Demelier <demelier.david@gmail.com> wrote:
> > Hello,
> >
> > I know this is a awful subject, but I recently tried a Gentoo on my laptop
> > and I was surprised to see Linux booting about 2-3 times faster than
> > FreeBSD.
> >
> > I don't talk about the init/rc script but only kernel initialisation. For
> > linux kernel it's around 5-6 seconds vs 15-18 seconds for FreeBSD.
> >
> > Why FreeBSD is so slower than Linux to boot the kernel?
> >
>
> USB probe times for FreeBSD are extremely
> long. I'm not sure of Linux parallelizes this
> or just waits until rc time.
>
> Wireless seems to be a similar issue here.
also timeouts in freebsd were chosen very conservatively. you might want to
alter those. examples are ATA or CAM timeouts.
also there seem to be a number of hardcoded delays present in some code which
have to be altered in the source tree. an example is the folowing code in the
boot stage 2 (boot2, but also present in gptboot and the zfs counterparts):
if (autoboot && keyhit(3)) {
cheers.
alex
>
> --
> --
--
a13x
help
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20110305131718.GA57122>