libperf: Move 'page_size' global variable to libperf

We need the 'page_size' variable in libperf, so move it there.

Add a libperf_init() as a global libperf init function to obtain this
value via sysconf() at tool start.

Committer notes:

Add internal/lib.h to tools/perf/ files using 'page_size', sometimes
replacing util.h with it if that was the only reason for having util.h
included.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lore.kernel.org/lkml/20190913132355.21634-33-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/arch/x86/tests/intel-cqm.c

@@ -5,6 +5,7 @@
 #include "evlist.h"
 #include "evsel.h"
 #include "arch-tests.h"
+#include <internal/lib.h> // page_size
 
 #include <signal.h>
 #include <sys/mman.h>

tools/perf/arch/x86/tests/rdpmc.c

@@ -13,7 +13,7 @@
 #include "tests/tests.h"
 #include "cloexec.h"
 #include "event.h"
-#include "util.h" // page_size
+#include <internal/lib.h> // page_size
 #include "arch-tests.h"
 
 static u64 rdpmc(unsigned int counter)

tools/perf/arch/x86/util/intel-bts.c

@@ -23,7 +23,7 @@
 #include "../../util/tsc.h"
 #include "../../util/auxtrace.h"
 #include "../../util/intel-bts.h"
-#include "../../util/util.h" // page_size
+#include <internal/lib.h> // page_size
 
 #define KiB(x) ((x) * 1024)
 #define MiB(x) ((x) * 1024 * 1024)

tools/perf/arch/x86/util/intel-pt.c

@@ -27,7 +27,7 @@
 #include "../../util/record.h"
 #include "../../util/target.h"
 #include "../../util/tsc.h"
-#include "../../util/util.h" // page_size
+#include <internal/lib.h> // page_size
 #include "../../util/intel-pt.h"
 
 #define KiB(x) ((x) * 1024)

tools/perf/arch/x86/util/machine.c

@@ -4,7 +4,7 @@
 #include <limits.h>
 #include <stdlib.h>
 
-#include "../../util/util.h" // page_size
+#include <internal/lib.h> // page_size
 #include "../../util/machine.h"
 #include "../../util/map.h"
 #include "../../util/symbol.h"