[PATCH 3/4] perf tool: Fix build when sysconf doesn't support cache line size

[Chris Phlipot]

Enable perf to build on libc implementations where sysconf() doesn't
support _SC_LEVEL1_DCACHE_LINESIZE as a parameter.

For example, the Bionic implementation does not support this as a
paremter. Older versions of Bionic will throw an error when this is passed
in as a parameter, and more recent versions will just return 0 as the
cache line size.

Signed-off-by: Chris Phlipot <cphlip...@gmail.com>
---
 tools/perf/perf.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/tools/perf/perf.c b/tools/perf/perf.c
index 8f21922..113ca5b 100644
--- a/tools/perf/perf.c
+++ b/tools/perf/perf.c
@@ -509,7 +509,11 @@ int main(int argc, const char **argv)
 
        /* The page_size is placed in util object. */
        page_size = sysconf(_SC_PAGE_SIZE);
+#ifdef _SC_LEVEL1_DCACHE_LINESIZE
        cacheline_size = sysconf(_SC_LEVEL1_DCACHE_LINESIZE);
+#else
+       cacheline_size = 0;
+#endif
 
        if (sysctl__read_int("kernel/perf_event_max_stack", &value) == 0)
                sysctl_perf_event_max_stack = value;
-- 
2.7.4