[PATCH 11/11] perf record: Fix mmap error output condition

From: Jiri Olsa
Date: Sat Oct 20 2012 - 10:33:54 EST

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 <jolsa@xxxxxxxxxx>
Cc: Arnaldo Carvalho de Melo <acme@xxxxxxxxxxxxxxxxxx>
Cc: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxx>
Cc: Paul Mackerras <paulus@xxxxxxxxx>
Cc: Corey Ashford <cjashfor@xxxxxxxxxxxxxxxxxx>
Cc: Frederic Weisbecker <fweisbec@xxxxxxxxx>
Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
tools/perf/builtin-record.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
index 3cf7fe2..93dc67e 100644
--- a/tools/perf/builtin-record.c
+++ b/tools/perf/builtin-record.c
@@ -358,7 +358,8 @@ try_again:
"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 {

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