The original port of ftrace to PowerPC kept a lot of the code used
by x86. Some of this code was to handle x86's 5 byte instruction.
This was handled by using character arrays to manipulate the
code.
PowerPC has a consistent 4 byte instruction. Using unsigned ints
makes the code more efficient as well as more readable.
By converting to use unsigned ints to represent instructions,
I was able to remove the side effects that were needed for
manipulating character strings.
i.e. memcpy and memcmp
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
This patch ports the function graph tracer for PowerPC, but only
for static function tracing.
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
The TOCS used by modules are different than the one used by
the core kernel code. The function graph tracer must save and
restore the TOC whenever it traces a module call. But this
is an added overhead to burden the majority of core kernel
code being traced.
Benjamin Herrenschmidt suggested in testing the entry of
the call to tell if it is a core kernel function or a module.
He recommended using the REGION_ID() macro to perform this test.
This patch implements Benjamin's idea, and uses a different
return_to_handler routine dependent on if the entry is a core
kernel function or not. The module version saves the TOC, where as
the core kernel version does not.
Geoff Lavand tested on PS3.
Tested-by: Geoff Levand <geoffrey.levand@am.sony.com>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
This is the port of the function graph tracer to PowerPC with
dynamic tracing.
Geoff Lavand tested on PS3.
Tested-by: Geoff Levand <geoffrey.levand@am.sony.com>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
This is a port of the function graph tracer that was written by
Frederic Weisbecker for the x86.
This only works for PPC64 at the moment and only for static tracing.
PPC32 and dynamic function graph tracing support will come later.
The trace produces a visual calling of functions:
# tracer: function_graph
#
# CPU DURATION FUNCTION CALLS
# | | | | | | |
0) 2.224 us | }
0) ! 271.024 us | }
0) ! 320.080 us | }
0) ! 324.656 us | }
0) ! 329.136 us | }
0) | .put_prev_task_fair() {
0) | .update_curr() {
0) 2.240 us | .update_min_vruntime();
0) 6.512 us | }
0) 2.528 us | .__enqueue_entity();
0) + 15.536 us | }
0) | .pick_next_task_fair() {
0) 2.032 us | .__pick_next_entity();
0) 2.064 us | .__clear_buddies();
0) | .set_next_entity() {
0) 2.672 us | .__dequeue_entity();
0) 6.864 us | }
Geoff Lavand tested on PS3.
Tested-by: Geoff Levand <geoffrey.levand@am.sony.com>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Michael Neuling reported a compile bug when dynamic ftrace was
configured in and modules were not. This was due to the ftrace
code referencing module specific structures.
Reported-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Impact: cleanup
The PowerPC ftrace code uses a hacked up DEBUGP macro for prints.
This patch converts it to the standard pr_debug.
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Impact: fix dynamic ftrace with large modules in PPC64
The math to calculate the offset into the TOC that is taken from reading
the trampoline is incorrect. The bottom half of the offset is a signed
extended short. The current code was using an OR to create the offset
when it should have been using an addition.
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Acked-by: Geoff Levand <geoffrey.levand@am.sony.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Impact: clean up
Paul Mackerras pointed out that the code to determine if the branch
can reach the destination is incorrect. Michael Ellerman suggested
to pull out the code from create_branch and use that.
Simply using create_branch is probably the best.
Reported-by: Michael Ellerman <michael@ellerman.id.au>
Reported-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: fix to PowerPC code modification
After modifying code it is essential to flush the icache. This patch
adds the missing flush.
Reported-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: clean up and robustness addition
This patch addresses the comments made by Paul Mackerras.
It removes the type casting between unsigned int and unsigned char
pointers, and replaces them with a use of all unsigned int.
Verification that the jump is indeed made to a trampoline has also
been added.
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: add ability to trace modules on 32 bit PowerPC
This patch performs the necessary trampoline calls to handle
modules with dynamic ftrace on 32 bit PowerPC.
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Impact: Allow 64 bit PowerPC to trace modules with dynamic ftrace
This adds code to handle the PPC64 module trampolines, and allows for
PPC64 to use dynamic ftrace.
Thanks to Paul Mackerras for these updates:
- fix the mod and rec->arch.mod NULL checks.
- fix to is_bl_op compare.
Thanks to Milton Miller for:
- finding the nasty race with using two nops, and recommending
instead that I use a branch 8 forward.
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Impact: use cleaner probe_kernel API over assembly
Using probe_kernel_read/write interface is a much cleaner approach
than the current assembly version.
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Impact: update to PowerPC ftrace arch API
This patch converts PowerPC to use the new dynamic ftrace arch API.
Thanks to Paul Mackennas for pointing out the mistakes of my original
test_24bit_addr function.
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
The entire file of ftrace.c in the arch code needs to be marked
as notrace. It is much cleaner to do this from the Makefile with
CFLAGS_REMOVE_ftrace.o.
[ powerpc already had this in its Makefile. ]
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
The arch dependent function ftrace_mcount_set was only used by the daemon
start up code. This patch removes it.
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Record the address of the mcount call-site. Currently all archs except sparc64
record the address of the instruction following the mcount call-site. Some
general cleanups are entailed. Storing mcount addresses in rec->ip enables
looking them up in the kprobe hash table later on to check if they're kprobe'd.
Signed-off-by: Abhishek Sagar <sagar.abhishek@gmail.com>
Cc: davem@davemloft.net
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This patch cleans up the ftrace code in PowerPC based on the comments from
Michael Ellerman.
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Cc: Michael Ellerman <michael@ellerman.id.au>
Cc: proski@gnu.org
Cc: a.p.zijlstra@chello.nl
Cc: Pekka Paalanen <pq@iki.fi>
Cc: Steven Rostedt <srostedt@redhat.com>
Cc: linuxppc-dev@ozlabs.org
Cc: Soeren Sandmann Pedersen <sandmann@redhat.com>
Cc: paulus@samba.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This patch adds full support for ftrace for PowerPC (both 64 and 32 bit).
This includes dynamic tracing and function filtering.
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
