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

MFC r257037: Redefine the io provider using the SDT(9) macros

MFC slacker: markj

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

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

Add FBT for PowerPC DTrace. Also, clean up the DTrace assembly code,
much of which is not necessary for PowerPC.

The FBT module can likely be factored into 3 separate files: common,
intel, and powerpc, rather than duplicating most of the code between
the x86 and PowerPC flavors.

All DTrace modules for PowerPC will be MFC'd together once Fasttrap is
completed.

The dtnfsclient module dependency should only be added if the old NFS
client support was compiled in.

Initial commit of an I/O provider for DTrace on FreeBSD.

These probes are most useful when looking into the structures
they provide, which are listed in io.d. For example:

dtrace -n 'io:genunix::start { printf("%d\n", args[0]->bio_bcount); }'

Note that the I/O systems in FreeBSD and Solaris/Illumos are sufficiently
different that there is not a 1:1 mapping from scripts that work
with one to the other.
MFC after: 1 month

Add DTrace support to the new NFS client. This is essentially
cloned from the old NFS client, plus additions for NFSv4. A
review of this code is in progress, however it was felt by the
reviewer that it could go in now, before code slush. Any changes
required by the review can be committed as bug fixes later.

add DTrace systrace support for linux32 and freebsd32 on amd64 syscalls

Add systrace_linux32 and systrace_freebsd32 modules which provide
support for tracing compat system calls in addition to native system
call tracing provided by systrace module.

Provided that all the systrace modules are loaded now you can select
what syscalls to trace in the following manner:

syscall::xxx:yyy - work on all system calls that match the specification
syscall:freebsd:xxx:yyy - only native system calls
syscall:linux32:xxx:yyy - linux32 compat system calls
syscall:freebsd32:xxx:yyy - freebsd32 compat system calls on amd64

PR: kern/152822
Submitted by: Artem Belevich <fbsdlist@src.cx>
Reviewed by: jhb (earlier version)
MFC after: 3 weeks

Enable fasttrap and make dtraceall depend on fasttrap when building i386
or amd64.

Sponsored by: The FreeBSD Foundation
> Description of fields to fill in above: 76 columns --|
> PR: If a GNATS PR is affected by the change.
> Submitted by: If someone else sent in the change.
> Reviewed by: If someone else reviewed your modification.
> Approved by: If you needed approval for this commit.
> Obtained from: If the change is from a third party.
> MFC after: N [day[s]|week[s]|month[s]]. Request a reminder email.
> Security: Vulnerability reference (one per line) or description.
> Empty fields above will be automatically removed.

M dtrace/dtraceall/dtraceall.c
M dtrace/Makefile

Add the OpenSolaris dtrace lockstat provider. The lockstat provider
adds probes for mutexes, reader/writer and shared/exclusive locks to
gather contention statistics and other locking information for
dtrace scripts, the lockstat(1M) command and other potential
consumers.

Reviewed by: attilio jhb jb
Approved by: gnn (mentor)

Add dtnfsclient, a first cut at an NFSv2/v3 client reuest DTrace
provider. The NFS client exposes 'start' and 'done' probes for NFSv2
and NFSv3 RPCs when using the new RPC implementation, passing in the
vnode, mbuf chain, credential, and NFSv2 or NFSv3 procedure number.
For 'done' probes, the error number is also available.

Probes are named in the following way:

...
nfsclient:nfs2:write:start
nfsclient:nfs2:write:done
...
nfsclient:nfs3:access:start
nfsclient:nfs3:access:done
...

Access to the unmarshalled arguments is not easily available at this
point in the stack, but the passed probe arguments are sufficient to
to a lot of interesting things in practice. Technically, these probes
may cover multiple RPC retransmits, and even transactions if the
transaction ID change as a result of authentication failure or a
jukebox error from the server, but usefully capture the intent of a
single NFS request, such as access, getattr, write, etc.

Typical use might involve profiling RPC latency by system call, number
of RPCs, how often a getattr leads to a call to access, when failed
access control checks occur, etc. More detailed RPC information might
best be provided by adding a krpc provider. It would also be useful
to add NFS client probes for events such as the access cache or
attribute cache satisfying requests without an RPC.

Sponsored by: Google, Inc.
MFC after: 1 month

Remove the dependency on lockstat. That its still work in progress.

Add the DTrace kernel module makefiles.