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>
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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
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