Date: Wed, 13 Jun 2012 17:49:55 -0500 From: Russell Cattelan <cattelan@thebarn.com> To: freebsd-hackers@freebsd.org Subject: Re: FreeBSD Boot Times Message-ID: <4FD91913.20607@thebarn.com> In-Reply-To: <20336.1339571779@critter.freebsd.dk> References: <20336.1339571779@critter.freebsd.dk>
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This is an OpenPGP/MIME signed message (RFC 2440 and 3156) --------------enigB838464551549E703833768C Content-Type: multipart/mixed; boundary="------------050802040009090709000206" This is a multi-part message in MIME format. --------------050802040009090709000206 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable On 6/13/12 2:16 AM, Poul-Henning Kamp wrote: > In message <alpine.BSF.2.00.1206130909310.73934@wojtek.tensor.gdynia.pl= >, Wojci > ech Puchar writes: >=20 > One of the major slowdowns is that we do all the device drivers > serially & synchronously. Yes definitely. I have been looking into how to potentially defer or parallelize device_attach'es. Defer is turning out to be hard enough since each system is has different requirements to reach a state where it can run /sbin/init. I've started with the John Baldwin's multipass work and have a system stops probing/attaching devices and allows the boot to continue on. The remaining passes I'm triggering from userspace once the system is up.= This is all very crude at this point and has been an some work just to understand how the kernel startup code all links together. Note systemd looks interesting from from a demand based startup scheme much like apples launchd. (note systemd uses linux process groups so porting it would take some effort) Ideally it would be nice to get to the point where many devices are only attached once there is a demand for it. Say network interfaces for example: attach it once the init scripts need to config it and then hopefully in an async fashion. Unfortunately that will require locking a bit more fine grain than the current "Giant" lock. -Russell >=20 --------------050802040009090709000206-- --------------enigB838464551549E703833768C Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.12 (Darwin) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/ iEYEARECAAYFAk/ZGRMACgkQNRmM+OaGhBhdWACfdiYT9Jn+xELa3qOnK8FNm20Y lX0An1l2IuHPa50ZGNORnqL/f3E6XcFW =OSKA -----END PGP SIGNATURE----- --------------enigB838464551549E703833768C--
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