tracing: Remove kmemtrace ftrace plugin

We have been resisting new ftrace plugins and removing existing
ones, and kmemtrace has been superseded by kmem trace events
and perf-kmem, so we remove it.

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Acked-by: Pekka Enberg <penberg@cs.helsinki.fi>
Acked-by: Eduard - Gabriel Munteanu <eduard.munteanu@linux360.ro>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Steven Rostedt <rostedt@goodmis.org>
[ remove kmemtrace from the makefile, handle slob too ]
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>

kernel/trace/Kconfig

@@ -354,26 +354,6 @@ config STACK_TRACER
 
 	  Say N if unsure.
 
-config KMEMTRACE
-	bool "Trace SLAB allocations"
-	select GENERIC_TRACER
-	help
-	  kmemtrace provides tracing for slab allocator functions, such as
-	  kmalloc, kfree, kmem_cache_alloc, kmem_cache_free, etc. Collected
-	  data is then fed to the userspace application in order to analyse
-	  allocation hotspots, internal fragmentation and so on, making it
-	  possible to see how well an allocator performs, as well as debug
-	  and profile kernel code.
-
-	  This requires an userspace application to use. See
-	  Documentation/trace/kmemtrace.txt for more information.
-
-	  Saying Y will make the kernel somewhat larger and slower. However,
-	  if you disable kmemtrace at run-time or boot-time, the performance
-	  impact is minimal (depending on the arch the kernel is built for).
-
-	  If unsure, say N.
-
 config WORKQUEUE_TRACER
 	bool "Trace workqueues"
 	select GENERIC_TRACER