perf tools: Check mmap pages value early

Move the check of the mmap_pages value to the options parsing time, so
we could rely on this value on other parts of code.

Related changes come in the next patches.

Also changes perf_evlist::mmap_len to proper size_t type.

Signed-off-by: Jiri Olsa <jolsa@redhat.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1378031796-17892-2-git-send-email-jolsa@redhat.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

1 files changed, 37 insertions, 9 deletions

diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c
index f9f77bee0b1b..4283f49ca0ab 100644
--- a/tools/perf/util/evlist.c
+++ b/tools/perf/util/evlist.c
@@ -18,6 +18,7 @@
 #include <unistd.h>
 
 #include "parse-events.h"
+#include "parse-options.h"
 
 #include <sys/mman.h>
 
@@ -672,6 +673,40 @@ out_unmap:
         return -1;
 }
 
+static size_t perf_evlist__mmap_size(unsigned long 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 0;
+
+        return (pages + 1) * page_size;
+}
+
+int perf_evlist__parse_mmap_pages(const struct option *opt, const char *str,
+                                  int unset __maybe_unused)
+{
+        unsigned int pages, *mmap_pages = opt->value;
+        size_t size;
+        char *eptr;
+
+        pages = strtoul(str, &eptr, 10);
+        if (*eptr != '\0') {
+                pr_err("failed to parse --mmap_pages/-m value\n");
+                return -1;
+        }
+
+        size = perf_evlist__mmap_size(pages);
+        if (!size) {
+                pr_err("--mmap_pages/-m value must be a power of two.");
+                return -1;
+        }
+
+        *mmap_pages = pages;
+        return 0;
+}
+
 /** perf_evlist__mmap - Create per cpu maps to receive events
  *
  * @evlist - list of events
@@ -695,14 +730,6 @@ int perf_evlist__mmap(struct perf_evlist *evlist, unsigned int pages,
         const struct thread_map *threads = evlist->threads;
         int prot = PROT_READ | (overwrite ? 0 : PROT_WRITE), mask;
 
-        /* 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;
-
         if (evlist->mmap == NULL && perf_evlist__alloc_mmap(evlist) < 0)
                 return -ENOMEM;
 
@@ -710,7 +737,8 @@ int perf_evlist__mmap(struct perf_evlist *evlist, unsigned int pages,
                 return -ENOMEM;
 
         evlist->overwrite = overwrite;
-        evlist->mmap_len = (pages + 1) * page_size;
+        evlist->mmap_len = perf_evlist__mmap_size(pages);
+        mask = evlist->mmap_len - page_size - 1;
 
         list_for_each_entry(evsel, &evlist->entries, node) {
                 if ((evsel->attr.read_format & PERF_FORMAT_ID) &&