perf record: Fix mmap error output condition

The mmap_pages default value is not power of 2 (UINT_MAX).

Together with perf_evlist__mmap function returning error value different
from EPERM, we get misleading error message: "--mmap_pages/-m value must
be a power of two."

Fixing this by adding extra check for UINT_MAX value for this error
condition.

Signed-off-by: Jiri Olsa <[email protected]>
Cc: Corey Ashford <[email protected]>
Cc: Frederic Weisbecker <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Paul Mackerras <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>

Author: Jiri Olsa

tools/perf/builtin-record.c

@@ -363,7 +363,8 @@ static int perf_record__open(struct perf_record *rec)
 			       "or try again with a smaller value of -m/--mmap_pages.\n"
 			       "(current value: %d)\n", opts->mmap_pages);
 			rc = -errno;
-		} else if (!is_power_of_2(opts->mmap_pages)) {
+		} else if (!is_power_of_2(opts->mmap_pages) &&
+			   (opts->mmap_pages != UINT_MAX)) {
 			pr_err("--mmap_pages/-m value must be a power of two.");
 			rc = -EINVAL;
 		} else {