Copy stable/10@r272459 to releng/10.1 as part of
the 10.1-RELEASE process.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Copy head (r256279) to stable/10 as part of the 10.0-RELEASE cycle.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

/* -> /*- for copyright notices, minor format tweaks as necessary

Change the return value of sema_timedwait() so it returns 0 on
success and a proper errno value on failure. This makes it
consistent with cv_timedwait(), and paves the way for the
introduction of functions such as sema_timedwait_sig() which can
fail in multiple ways.

Bump __FreeBSD_version and add a note to UPDATING.

Approved by: scottl (ips driver), arch

Use __FBSDID().

Change callers of mtx_init() to pass in an appropriate lock type name. In
most cases NULL is passed, but in some cases such as network driver locks
(which use the MTX_NETWORK_LOCK macro) and UMA zone locks, a name is used.

Tested on: i386, alpha, sparc64

Repeat after me -- "Use of ANSI string concatenation can be bad."
In this case, C99's __func__ is properly defined as:

static const char __func__[] = "function-name";

and GCC 3.1 will not allow it to be used in bogus string concatenation.

Implement kernel semaphores.

Reviewed by: jhb