Merge branch 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull perf updates from Ingo Molnar:
 "On the kernel side the main changes in this cycle were:

   - Add Intel Kaby Lake CPU support (Srinivas Pandruvada)

   - AMD uncore driver updates for fam17 (Janakarajan Natarajan)

   - Intel/PT updates and core events optimizations and cleanups
     (Alexander Shishkin)

   - cgroups events fixes (David Carrillo-Cisneros)

   - kprobes improvements (Masami Hiramatsu)

   - ... plus misc fixes and updates.

  On the tooling side the main changes were:

   - Support clang build in tools/{perf,lib/{bpf,traceevent,api}} with
     CC=clang, to, for instance, take advantage of better warnings
     (Arnaldo Carvalho de Melo):

   - Introduce the 'delta-abs' 'perf diff' compute method, that orders
     the histogram entries by the absolute value of the percentage delta
     for a function in two perf.data files, i.e. the functions that
     changed the most (increase or decrease in samples) comes first
     (Namhyung Kim)

   - Add support for parsing Intel uncore vendor event files and add
     uncore vendor events for the Intel server processors (Haswell,
     Broadwell, IvyBridge), Xeon Phi (Knights Landing) and Broadwell DE
     (Andi Kleen)

   - Introduce 'perf ftrace' a perf front end to the kernel's ftrace
     function and function_graph tracer, defaulting to the
     "function_graph" tracer, more work will be done in reviving this
     effort, forward porting it from its initial patch submission
     (Namhyung Kim)

   - Add 'e' and 'c' hotkeys to expand/collapse call chains for a single
     hist entry in the 'perf report' and 'perf top' TUI (Jiri Olsa)

   - Account thread wait time (off CPU time) separately: sleep, iowait
     and preempt, based on the prev_state of the last event, show the
     breakdown when using "perf sched timehist --state" (Namhyumg Kim)

   - Add more triggers to switch the output file (perf.data.TIMESTAMP).

     Now, in addition to switching to a different output file when
     receiving a SIGUSR2, one can also specify file size and time based
     triggers:

           perf record -a --switch-output=signal

     is equivalent to what we had before:

           perf record -a --switch-output

     While we can also ask for the file to be "sliced" by size, taking
     into account that that will happen only when we get woken up by the
     kernel, i.e. one has to take into account the --mmap-pages (the
     size of the perf mmap ring buffer):

           perf record -a --switch-output=2G

     will break the perf.data output into multiple files limited to 2GB
     of samples, right when generating the output.

     For time based samples, alert() will be used, so to have 1 minute
     limited perf.data output files:

          perf record -a --switch-output=1m

     (Jiri Olsa)

   - Improve 'perf trace' (Arnaldo Carvalho de Melo)

   - 'perf kallsyms' toy tool to look for extended symbol information on
     the running kernel and demonstrate the machine/thread/symbol APIs
     for use in other tools, such as 'perf probe' (Arnaldo Carvalho de
     Melo)

   - ... plus tons of other changes, see the shortlog and Git log for
     details"

* 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (131 commits)
  perf tools: Add missing parse_events_error() prototype
  perf pmu: Fix check for unset alias->unit array
  perf tools: Be consistent on the type of map->symbols[] interator
  perf intel pt decoder: clang has no -Wno-override-init
  perf evsel: Do not put a variable sized type not at the end of a struct
  perf probe: Avoid accessing uninitialized 'map' variable
  perf tools: Do not put a variable sized type not at the end of a struct
  perf record: Do not put a variable sized type not at the end of a struct
  perf tests: Synthesize struct instead of using field after variable sized type
  perf bench numa: Make sure dprintf() is not defined
  Revert "perf bench futex: Sanitize numeric parameters"
  tools lib subcmd: Make it an error to pass a signed value to OPTION_UINTEGER
  tools: Set the maximum optimization level according to the compiler being used
  tools: Suppress request for warning options not existent in clang
  samples/bpf: Reset global variables
  samples/bpf: Ignore already processed ELF sections
  samples/bpf: Add missing header
  perf symbols: dso->name is an array, no need to check it against NULL
  perf tests record: No need to test an array against NULL
  perf symbols: No need to check if sym->name is NULL
  ...

1 files changed, 8 insertions, 2 deletions

diff --git a/tools/perf/Makefile.config b/tools/perf/Makefile.config
index 76c84f0eec52..2b941efadb04 100644
--- a/tools/perf/Makefile.config
+++ b/tools/perf/Makefile.config
@@ -144,8 +144,12 @@ ifndef DEBUG
 endif
 
 ifeq ($(DEBUG),0)
+ifeq ($(CC), clang)
+  CFLAGS += -O3
+else
   CFLAGS += -O6
 endif
+endif
 
 ifdef PARSER_DEBUG
   PARSER_DEBUG_BISON := -t
@@ -291,8 +295,10 @@ else
       endif
     endif
     ifneq ($(feature-dwarf), 1)
-      msg := $(warning No libdw.h found or old libdw.h found or elfutils is older than 0.138, disables dwarf support. Please install new elfutils-devel/libdw-dev);
-      NO_DWARF := 1
+      ifndef NO_DWARF
+        msg := $(warning No libdw.h found or old libdw.h found or elfutils is older than 0.138, disables dwarf support. Please install new elfutils-devel/libdw-dev);
+        NO_DWARF := 1
+      endif
     else
       ifneq ($(feature-dwarf_getlocations), 1)
         msg := $(warning Old libdw.h, finding variables at given 'perf probe' point will not work, install elfutils-devel/libdw-dev >= 0.157);