This avoids the fsck-on-reboot symptoms if you're shutting down with a
hung or unreachable NFS server mounted. Also remove non-local
filesystems from the mount list to prevent the system hanging when it tries
to unmount them (for the same reason).
Drew points out that there's a good argument for forcibly removing all
"non syncable" filesystems from the mount list (eg. NFS mounts, disks
that aren't responding, etc.) as this then allows you to sync and
cleanly unmount their parents. No such change is included in this
patch.
Submitted by: Andrew Gallatin <gallatin@cs.duke.edu>
pid space somewhat more sparse which improves the performance of finding
an unused pid on systems with large numbers of processes. The new value
was chosen so that it doesn't overflow the 5 digit pid fields in various
programs.
This yields startling performance increases for NFS clients for many
access profiles, due to the fact that ACCESS results are persistently
cached in the namecache in many cases.
Note that the code is somewhat conservative in that it requires an
exact credential match for a cache hit. This bloats the nfsnode
structure by sizeof(struct ucred) (96 bytes). Any less conservative
approach opens the possibility for a false veto in eg. setuid
applications. Alternative suggestions would be welcomed.
The cache is normally disabled, to activate set the sysctl variable
vfs.nfs.access_cache_timeout to a nonzero value. This is the time in
seconds that a cached entry will be considered valid; useful values appear
to be 2-10 seconds. Performance of the cache can be monitored with the
vfs.nfs.access_cache_hits and vfs.nfs.access_cache_hits variables.
basically do a on-the-fly defragmentation of the FFS filesystem, changing
file block allocations to make them contiguous. Thanks to Kirk McKusick
for providing hints on what needed to be done to get this working.
configured in the kernel. It gives them a device name of "none" and
monotonically incrementing unit numbers. (starting at 0) Before, pciconf
would just skip over unconfigured devices. (unconfigured devices can be
detected because they have a null string for a device name)
Update the man page to reflect the new pciconf output. Unfortunately, this
causes the sample 'pciconf -l' output lines to wrap, but I'm not sure what
to do about that really.
If anyone presents a reasonable case for printing out something other than
"none1" for unconfigured devices, I'm willing to listen.
