These patches provide a kernel tracing interface called "trace".
The motivation for "trace" is to:
- Provide a simple set of tracing primitives that will utilize the
high-
performance and low-overhead of relayfs for passing traces data from
kernel to user space.
- Provide a common user interface for managing kernel traces.
- Allow for binary as well as ascii trace data.
- Incorporate features from the systemtap runtime that are
useful to others.
History- Versions of this code have been submitted for review under
a couple of different names. The original submission was called UTT,
it was later re-submitted as GTSC. Christoph Hellwig commented "The
code looks fine ...but the name is just dumb". Following Christoph's
advice, I changed the name to simply "Trace".
This patch addresses review comments made by Christoph Hellwig and
Mathieu
Desnoyers. Changes include the addition of a mutex and synchronization
protecting trace state changes (using RCU) and the reduction of the
number of exports.
Patches are against 2.6.23-rc4-mm1
Required patches:
1/2 Trace code and documentation
2/2 Relay reset consumed (required for trace's "rewind" feature")
Signed-off-by: David Wilder <dwilder@us.ibm.com>