The ftrace function_graph time measurements of a given function is not
accurate according to those recorded by ftrace using the function
filters. This change pulls the x86_64 fix from 'commit 722b3c7469
("ftrace/graph: Trace function entry before updating index")' into the
sparc specific prepare_ftrace_return which stops ftrace from
counting interrupted tasks in the time measurement.
Example measurements for select_task_rq_fair running "hackbench 100
process 1000":
| tracing/trace_stat/function0 | function_graph
Before patch | 2.802 us | 4.255 us
After patch | 2.749 us | 3.094 us
Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Storing this value will help prevent unwinders from getting out of sync
with the function graph tracer ret_stack. Now instead of needing a
stateful iterator, they can compare the return address pointer to find
the right ret_stack entry.
Note that an array of 50 ftrace_ret_stack structs is allocated for every
task. So when an arch implements this, it will add either 200 or 400
bytes of memory usage per task (depending on whether it's a 32-bit or
64-bit platform).
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Byungchul Park <byungchul.park@lge.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Nilay Vaish <nilayvaish@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/a95cfcc39e8f26b89a430c56926af0bb217bc0a1.1471607358.git.jpoimboe@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
As the data parameter is not really used by any ftrace_dyn_arch_init,
remove that from ftrace_dyn_arch_init. This also removes the addr
local variable from ftrace_init which is now unused.
Note the documentation was imprecise as it did not suggest to set
(*data) to 0.
Link: http://lkml.kernel.org/r/1393268401-24379-4-git-send-email-jslaby@suse.cz
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: linux-arch@vger.kernel.org
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
No architecture uses the "data" parameter in ftrace_dyn_arch_init() in any
way, it just sets the value to 0. And this is used as a return value
in the caller -- ftrace_init, which just checks the retval against
zero.
Note there is also "return 0" in every ftrace_dyn_arch_init. So it is
enough to check the retval and remove all the indirect sets of data on
all archs.
Link: http://lkml.kernel.org/r/1393268401-24379-3-git-send-email-jslaby@suse.cz
Cc: linux-arch@vger.kernel.org
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Most implementations of arch_syscall_addr() are the same, so create a
default version in common code and move the one piece that differs (the
syscall table) to asm/syscall.h. New arch ports don't have to waste
time copying & pasting this simple function.
The s390/sparc versions need to be different, so document why.
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Acked-by: David S. Miller <davem@davemloft.net>
Acked-by: Paul Mundt <lethal@linux-sh.org>
Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
LKML-Reference: <1264498803-17278-1-git-send-email-vapier@gentoo.org>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
o Move all files from sparc64/kernel/ to sparc/kernel
- rename as appropriate
o Update sparc/Makefile to the changes
o Update sparc/kernel/Makefile to include the sparc64 files
NOTE: This commit changes link order on sparc64!
Link order had to change for either of sparc32 and sparc64.
And assuming sparc64 see more testing than sparc32 change link
order on sparc64 where issues will be caught faster.
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Liam R. Howlett