kernel_optimize_test/tools/build/feature/test-sync-compare-and-swap.c
Jiri Olsa e6c76d6203 perf build: Move feature checks code under tools/build
Moving feature checks code under tools/build directory.

Changing also $feature_dir to point to new feature directory location
and perf Makefiles to include Makefile.feature from new location.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: David Ahern <david.ahern@oracle.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/n/tip-3lamtb30dhf4wo99y1n8kxg0@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2015-03-21 14:53:35 -03:00

15 lines
251 B
C

#include <stdint.h>
volatile uint64_t x;
int main(int argc, char *argv[])
{
uint64_t old, new = argc;
argv = argv;
do {
old = __sync_val_compare_and_swap(&x, 0, 0);
} while (!__sync_bool_compare_and_swap(&x, old, new));
return old == new;
}