[PATCH] perf bench: Share 'start', 'end', 'runtime' global vars

[Arnaldo Carvalho de Melo <arnaldo.melo@gmail.com>]

Hi,

	Noticed with gcc 10 (fedora rawhide) that those variables were
not being declared as static, so end up with:

ld: /tmp/build/perf/bench/epoll-wait.o:/git/perf/tools/perf/bench/epoll-wait.c:93: multiple definition of `end'; /tmp/build/perf/bench/futex-hash.o:/git/perf/tools/perf/bench/futex-hash.c:40: first defined here
ld: /tmp/build/perf/bench/epoll-wait.o:/git/perf/tools/perf/bench/epoll-wait.c:93: multiple definition of `start'; /tmp/build/perf/bench/futex-hash.o:/git/perf/tools/perf/bench/futex-hash.c:40: first defined here
ld: /tmp/build/perf/bench/epoll-wait.o:/git/perf/tools/perf/bench/epoll-wait.c:93: multiple definition of `runtime'; /tmp/build/perf/bench/futex-hash.o:/git/perf/tools/perf/bench/futex-hash.c:40: first defined here
ld: /tmp/build/perf/bench/epoll-ctl.o:/git/perf/tools/perf/bench/epoll-ctl.c:38: multiple definition of `end'; /tmp/build/perf/bench/futex-hash.o:/git/perf/tools/perf/bench/futex-hash.c:40: first defined here
ld: /tmp/build/perf/bench/epoll-ctl.o:/git/perf/tools/perf/bench/epoll-ctl.c:38: multiple definition of `start'; /tmp/build/perf/bench/futex-hash.o:/git/perf/tools/perf/bench/futex-hash.c:40: first defined here
ld: /tmp/build/perf/bench/epoll-ctl.o:/git/perf/tools/perf/bench/epoll-ctl.c:38: multiple definition of `runtime'; /tmp/build/perf/bench/futex-hash.o:/git/perf/tools/perf/bench/futex-hash.c:40: first defined here
make[4]: *** [/git/perf/tools/build/Makefile.build:145: /tmp/build/perf/bench/perf-in.o] Error 1

	Just prefixing them with 'extern' in all but one (futex-hash.c)
seems to be enough, ok?

- Arnaldo

diff --git a/tools/perf/bench/epoll-ctl.c b/tools/perf/bench/epoll-ctl.c
index bb617e568841..8a7681fca8ab 100644
--- a/tools/perf/bench/epoll-ctl.c
+++ b/tools/perf/bench/epoll-ctl.c
@@ -35,7 +35,7 @@
 
 static unsigned int nthreads = 0;
 static unsigned int nsecs    = 8;
-struct timeval start, end, runtime;
+extern struct timeval start, end, runtime;
 static bool done, __verbose, randomize;
 
 /*
diff --git a/tools/perf/bench/epoll-wait.c b/tools/perf/bench/epoll-wait.c
index 7af694437f4e..170b96938275 100644
--- a/tools/perf/bench/epoll-wait.c
+++ b/tools/perf/bench/epoll-wait.c
@@ -90,7 +90,7 @@
 
 static unsigned int nthreads = 0;
 static unsigned int nsecs    = 8;
-struct timeval start, end, runtime;
+extern struct timeval start, end, runtime;
 static bool wdone, done, __verbose, randomize, nonblocking;
 
 /*
diff --git a/tools/perf/bench/futex-lock-pi.c b/tools/perf/bench/futex-lock-pi.c
index d0cae8125423..253ae62e618d 100644
--- a/tools/perf/bench/futex-lock-pi.c
+++ b/tools/perf/bench/futex-lock-pi.c
@@ -37,7 +37,7 @@ static bool silent = false, multi = false;
 static bool done = false, fshared = false;
 static unsigned int nthreads = 0;
 static int futex_flag = 0;
-struct timeval start, end, runtime;
+extern struct timeval start, end, runtime;
 static pthread_mutex_t thread_lock;
 static unsigned int threads_starting;
 static struct stats throughput_stats;