__get_cpu_var() is used for multiple purposes in the kernel source. One of
them is address calculation via the form &__get_cpu_var(x).  This calculates
the address for the instance of the percpu variable of the current processor
based on an offset.

Other use cases are for storing and retrieving data from the current
processors percpu area.  __get_cpu_var() can be used as an lvalue when
writing data or on the right side of an assignment.

__get_cpu_var() is defined as :

#define __get_cpu_var(var) (*this_cpu_ptr(&(var)))

__get_cpu_var() always only does an address determination. However, store
and retrieve operations could use a segment prefix (or global register on
other platforms) to avoid the address calculation.

this_cpu_write() and this_cpu_read() can directly take an offset into a
percpu area and use optimized assembly code to read and write per cpu
variables.

This patch converts __get_cpu_var into either an explicit address
calculation using this_cpu_ptr() or into a use of this_cpu operations that
use the offset.  Thereby address calculations are avoided and less registers
are used when code is generated.

At the end of the patch set all uses of __get_cpu_var have been removed so
the macro is removed too.

The patch set includes passes over all arches as well. Once these operations
are used throughout then specialized macros can be defined in non -x86
arches as well in order to optimize per cpu access by f.e.  using a global
register that may be set to the per cpu base.

Transformations done to __get_cpu_var()

1. Determine the address of the percpu instance of the current processor.

	DEFINE_PER_CPU(int, y);
	int *x = &__get_cpu_var(y);

    Converts to

	int *x = this_cpu_ptr(&y);

2. Same as #1 but this time an array structure is involved.

	DEFINE_PER_CPU(int, y[20]);
	int *x = __get_cpu_var(y);

    Converts to

	int *x = this_cpu_ptr(y);

3. Retrieve the content of the current processors instance of a per cpu
variable.

	DEFINE_PER_CPU(int, y);
	int x = __get_cpu_var(y)

   Converts to

	int x = __this_cpu_read(y);

4. Retrieve the content of a percpu struct

	DEFINE_PER_CPU(struct mystruct, y);
	struct mystruct x = __get_cpu_var(y);

   Converts to

	memcpy(&x, this_cpu_ptr(&y), sizeof(x));

5. Assignment to a per cpu variable

	DEFINE_PER_CPU(int, y)
	__get_cpu_var(y) = x;

   Converts to

	__this_cpu_write(y, x);

6. Increment/Decrement etc of a per cpu variable

	DEFINE_PER_CPU(int, y);
	__get_cpu_var(y)++

   Converts to

	__this_cpu_inc(y)

CC: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

Pull arch signal handling cleanup from Richard Weinberger:
 "This patch series moves all remaining archs to the get_signal(),
  signal_setup_done() and sigsp() functions.

  Currently these archs use open coded variants of the said functions.
  Further, unused parameters get removed from get_signal_to_deliver(),
  tracehook_signal_handler() and signal_delivered().

  At the end of the day we save around 500 lines of code."

* 'signal-cleanup' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/misc: (43 commits)
  powerpc: Use sigsp()
  openrisc: Use sigsp()
  mn10300: Use sigsp()
  mips: Use sigsp()
  microblaze: Use sigsp()
  metag: Use sigsp()
  m68k: Use sigsp()
  m32r: Use sigsp()
  hexagon: Use sigsp()
  frv: Use sigsp()
  cris: Use sigsp()
  c6x: Use sigsp()
  blackfin: Use sigsp()
  avr32: Use sigsp()
  arm64: Use sigsp()
  arc: Use sigsp()
  sas_ss_flags: Remove nested ternary if
  Rip out get_signal_to_deliver()
  Clean up signal_delivered()
  tracehook_signal_handler: Remove sig, info, ka and regs
  ...

Use sigsp() instead of the open coded variant.

Signed-off-by: Richard Weinberger <richard@nod.at>
Acked-by: Steven Miao <realmz6@gmail.com>

Use the more generic functions get_signal() signal_setup_done()
for signal delivery.

Signed-off-by: Richard Weinberger <richard@nod.at>
Acked-by: Steven Miao <realmz6@gmail.com>

Pull perf changes from Ingo Molnar:
 "Kernel side changes:

   - Consolidate the PMU interrupt-disabled code amongst architectures
     (Vince Weaver)

   - misc fixes

  Tooling changes (new features, user visible changes):

   - Add support for pagefault tracing in 'trace', please see multiple
     examples in the changeset messages (Stanislav Fomichev).

   - Add pagefault statistics in 'trace' (Stanislav Fomichev)

   - Add header for columns in 'top' and 'report' TUI browsers (Jiri
     Olsa)

   - Add pagefault statistics in 'trace' (Stanislav Fomichev)

   - Add IO mode into timechart command (Stanislav Fomichev)

   - Fallback to syscalls:* when raw_syscalls:* is not available in the
     perl and python perf scripts.  (Daniel Bristot de Oliveira)

   - Add --repeat global option to 'perf bench' to be used in benchmarks
     such as the existing 'futex' one, that was modified to use it
     instead of a local option.  (Davidlohr Bueso)

   - Fix fd -> pathname resolution in 'trace', be it using /proc or a
     vfs_getname probe point.  (Arnaldo Carvalho de Melo)

   - Add suggestion of how to set perf_event_paranoid sysctl, to help
     non-root users trying tools like 'trace' to get a working
     environment.  (Arnaldo Carvalho de Melo)

   - Updates from trace-cmd for traceevent plugin_kvm plus args cleanup
     (Steven Rostedt, Jan Kiszka)

   - Support S/390 in 'perf kvm stat' (Alexander Yarygin)

  Tooling infrastructure changes:

   - Allow reserving a row for header purposes in the hists browser
     (Arnaldo Carvalho de Melo)

   - Various fixes and prep work related to supporting Intel PT (Adrian
     Hunter)

   - Introduce multiple debug variables control (Jiri Olsa)

   - Add callchain and additional sample information for python scripts
     (Joseph Schuchart)

   - More prep work to support Intel PT: (Adrian Hunter)
     - Polishing 'script' BTS output
     - 'inject' can specify --kallsym
     - VDSO is per machine, not a global var
     - Expose data addr lookup functions previously private to 'script'
     - Large mmap fixes in events processing

   - Include standard stringify macros in power pc code (Sukadev
     Bhattiprolu)

  Tooling cleanups:

   - Convert open coded equivalents to asprintf() (Andy Shevchenko)

   - Remove needless reassignments in 'trace' (Arnaldo Carvalho de Melo)

   - Cache the is_exit syscall test in 'trace) (Arnaldo Carvalho de
     Melo)

   - No need to reimplement err() in 'perf bench sched-messaging', drop
     barf().  (Davidlohr Bueso).

   - Remove ev_name argument from perf_evsel__hists_browse, can be
     obtained from the other parameters.  (Jiri Olsa)

  Tooling fixes:

   - Fix memory leak in the 'sched-messaging' perf bench test.
     (Davidlohr Bueso)

   - The -o and -n 'perf bench mem' options are mutually exclusive, emit
     error when both are specified.  (Davidlohr Bueso)

   - Fix scrollbar refresh row index in the ui browser, problem exposed
     now that headers will be added and will be allowed to be switched
     on/off.  (Jiri Olsa)

   - Handle the num array type in python properly (Sebastian Andrzej
     Siewior)

   - Fix wrong condition for allocation failure (Jiri Olsa)

   - Adjust callchain based on DWARF debug info on powerpc (Sukadev
     Bhattiprolu)

   - Fix a risk for doing free on uninitialized pointer in traceevent
     lib (Rickard Strandqvist)

   - Update attr test with PERF_FLAG_FD_CLOEXEC flag (Jiri Olsa)

   - Enable close-on-exec flag on perf file descriptor (Yann Droneaud)

   - Fix build on gcc 4.4.7 (Arnaldo Carvalho de Melo)

   - Event ordering fixes (Jiri Olsa)"

* 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (123 commits)
  Revert "perf tools: Fix jump label always changing during tracing"
  perf tools: Fix perf usage string leftover
  perf: Check permission only for parent tracepoint event
  perf record: Store PERF_RECORD_FINISHED_ROUND only for nonempty rounds
  perf record: Always force PERF_RECORD_FINISHED_ROUND event
  perf inject: Add --kallsyms parameter
  perf tools: Expose 'addr' functions so they can be reused
  perf session: Fix accounting of ordered samples queue
  perf powerpc: Include util/util.h and remove stringify macros
  perf tools: Fix build on gcc 4.4.7
  perf tools: Add thread parameter to vdso__dso_findnew()
  perf tools: Add dso__type()
  perf tools: Separate the VDSO map name from the VDSO dso name
  perf tools: Add vdso__new()
  perf machine: Fix the lifetime of the VDSO temporary file
  perf tools: Group VDSO global variables into a structure
  perf session: Add ability to skip 4GiB or more
  perf session: Add ability to 'skip' a non-piped event stream
  perf tools: Pass machine to vdso__dso_findnew()
  perf tools: Add dso__data_size()
  ...

Pull tracing updates from Steven Rostedt:
 "This pull request has a lot of work done.  The main thing is the
  changes to the ftrace function callback infrastructure.  It's
  introducing a way to allow different functions to call directly
  different trampolines instead of all calling the same "mcount" one.

  The only user of this for now is the function graph tracer, which
  always had a different trampoline, but the function tracer trampoline
  was called and did basically nothing, and then the function graph
  tracer trampoline was called.  The difference now, is that the
  function graph tracer trampoline can be called directly if a function
  is only being traced by the function graph trampoline.  If function
  tracing is also happening on the same function, the old way is still
  done.

  The accounting for this takes up more memory when function graph
  tracing is activated, as it needs to keep track of which functions it
  uses.  I have a new way that wont take as much memory, but it's not
  ready yet for this merge window, and will have to wait for the next
  one.

  Another big change was the removal of the ftrace_start/stop() calls
  that were used by the suspend/resume code that stopped function
  tracing when entering into suspend and resume paths.  The stop of
  ftrace was done because there was some function that would crash the
  system if one called smp_processor_id()! The stop/start was a big
  hammer to solve the issue at the time, which was when ftrace was first
  introduced into Linux.  Now ftrace has better infrastructure to debug
  such issues, and I found the problem function and labeled it with
  "notrace" and function tracing can now safely be activated all the way
  down into the guts of suspend and resume

  Other changes include clean ups of uprobe code, clean up of the
  trace_seq() code, and other various small fixes and clean ups to
  ftrace and tracing"

* tag 'trace-3.17' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (57 commits)
  ftrace: Add warning if tramp hash does not match nr_trampolines
  ftrace: Fix trampoline hash update check on rec->flags
  ring-buffer: Use rb_page_size() instead of open coded head_page size
  ftrace: Rename ftrace_ops field from trampolines to nr_trampolines
  tracing: Convert local function_graph functions to static
  ftrace: Do not copy old hash when resetting
  tracing: let user specify tracing_thresh after selecting function_graph
  ring-buffer: Always run per-cpu ring buffer resize with schedule_work_on()
  tracing: Remove function_trace_stop and HAVE_FUNCTION_TRACE_MCOUNT_TEST
  s390/ftrace: remove check of obsolete variable function_trace_stop
  arm64, ftrace: Remove check of obsolete variable function_trace_stop
  Blackfin: ftrace: Remove check of obsolete variable function_trace_stop
  metag: ftrace: Remove check of obsolete variable function_trace_stop
  microblaze: ftrace: Remove check of obsolete variable function_trace_stop
  MIPS: ftrace: Remove check of obsolete variable function_trace_stop
  parisc: ftrace: Remove check of obsolete variable function_trace_stop
  sh: ftrace: Remove check of obsolete variable function_trace_stop
  sparc64,ftrace: Remove check of obsolete variable function_trace_stop
  tile: ftrace: Remove check of obsolete variable function_trace_stop
  ftrace: x86: Remove check of obsolete variable function_trace_stop
  ...

Signed-off-by: Ingo Molnar <mingo@kernel.org>

to collect some undefined section to the end of the data section and avoid section overlap

Signed-off-by: Steven Miao <realmz6@gmail.com>

Nothing sets function_trace_stop to disable function tracing anymore.
Remove the check for it in the arch code.

Link: http://lkml.kernel.org/r/3144266.ziutPk5CNZ@vapier

Acked-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

Transition to using the new generic PERF_PMU_CAP_NO_INTERRUPT method for
failing a sampling event when no PMU interrupt is available.

Signed-off-by: Vince Weaver <vincent.weaver@maine.edu>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Steven Miao <realmz6@gmail.com>
Cc: adi-buildroot-devel@lists.sourceforge.net
Link: http://lkml.kernel.org/r/alpine.DEB.2.10.1406150200360.16738@vincent-weaver-1.umelst.maine.edu
Signed-off-by: Ingo Molnar <mingo@kernel.org>