svn commit: r277204 - head/sys/amd64/conf

[Slawa Olhovchenkov]

On Thu, Jan 15, 2015 at 01:44:46PM +0000, Alexey Dokuchaev wrote:

> On Thu, Jan 15, 2015 at 04:23:03PM +0300, Slawa Olhovchenkov wrote:
> > On Thu, Jan 15, 2015 at 12:42:07AM +0000, Warner Losh wrote:
> > > New Revision: 277204
> > > URL: https://svnweb.freebsd.org/changeset/base/277204
> > > 
> > > Log:
> > >   New MINIMAL kernel config. The goal with this configuration is to
> > >   only compile in those options in GENERIC that cannot be loaded as
> > >   modules. ufs is still included because many of its options aren't
> > >   present in the kernel module. There's some other exceptions documented
> > 
> > Are you sure?
> > I think defining UFS options in kernel connfig affect to module too.
> > When I define this options in kernel config (w/o options FFS) I got
> > ufs.ko with this SU, quota, acl etc.
> > 
> > [...]
> > This is loadable too.
> 
> Right, it does not look like minimal to me either.  But I welcome the
> intention.  AFAIR last time we had a discussion about why our default
> kernel is not MINIMAL, it boiled down to two main problems: 1) loader's
> caching of disk reads (which makes loading *.ko's from /boot/loader.conf

reading large monolitic kernel is slow too.

> a PITA, esp. on ZFS), and 2) robust way to figure out which modules to
> load on an arbitrary user's system (so they won't have to write their
> /boot/loader.conf from scratch themselves).

/boot/loader.conf (with all modules currently present in GENERIC) may
be instaled by bsdinstall (and may be part of base.txz).

> Speaking of (1), I recall there was one or two attempts to address it
> (keyword: fast-loader-3.diff).  Can someone with more details on their
> hands comment a bit what had happened to that work and are there any
> ETA for it to get committed?  That would be a big leap forward towards
> minimal kernel which can be feasible enough to replace (or be a real
> alternative to) GENERIC in the future.

This is not only space saving.
This is allow to

kenv hw.cxgbe.nrxq10g=8 ; kldunload if_cxgbe ; kldload if_cxgbe ; /etc/netstart

only a few seconds downtime.