perf: builtin-record: Document and check that mmap_pages must be a power of two.

[linux-2.6-block.git] / tools / perf / util / evlist.c

diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c
index 963d63dde457bba5a32211c086064e0a045e7f8a..fa1837088ca880ca5968709326e94f22fa436db4 100644 (file)
--- a/tools/perf/util/evlist.c
+++ b/tools/perf/util/evlist.c
@@ -563,6 +563,8 @@ int perf_evlist__mmap(struct perf_evlist *evlist, unsigned int pages,
         /* 512 kiB: default amount of unprivileged mlocked memory */
         if (pages == UINT_MAX)
                 pages = (512 * 1024) / page_size;
+       else if (!is_power_of_2(pages))
+               return -EINVAL;
 
        mask = pages * page_size - 1;