Fix last COW INFO report, Skip test on non-linux platforms (#8301)

- the last COW report wasn't always read from the pipe
  (receiveLastChildInfo wasn't used)
- but in fact, there's no reason we won't always try to drain that pipe
  so i'm unifying receiveLastChildInfo with receiveChildInfo
- adjust threshold of the COW test when run in accurate mode
- add some prints in case this test fails again
- fix indentation, page size, and PID! in MacOS proc info

p.s. it seems that pri_pages_dirtied is always 0

1 files changed, 11 insertions, 8 deletions

diff --git a/src/zmalloc.c b/src/zmalloc.c
index 86b15b0ee..eacce67bd 100644
--- a/src/zmalloc.c
+++ b/src/zmalloc.c
@@ -580,15 +580,18 @@ size_t zmalloc_get_smap_bytes_by_field(char *field, long pid) {
 size_t zmalloc_get_smap_bytes_by_field(char *field, long pid) {
 #if defined(__APPLE__)
     struct proc_regioninfo pri;
-    if (proc_pidinfo(pid, PROC_PIDREGIONINFO, 0, &pri, PROC_PIDREGIONINFO_SIZE) ==
-	PROC_PIDREGIONINFO_SIZE) {
-	if (!strcmp(field, "Private_Dirty:")) {
-            return (size_t)pri.pri_pages_dirtied * 4096;
-	} else if (!strcmp(field, "Rss:")) {
-            return (size_t)pri.pri_pages_resident * 4096;
-	} else if (!strcmp(field, "AnonHugePages:")) {
+    if (pid == -1) pid = getpid();
+    if (proc_pidinfo(pid, PROC_PIDREGIONINFO, 0, &pri,
+                     PROC_PIDREGIONINFO_SIZE) == PROC_PIDREGIONINFO_SIZE)
+    {
+        int pagesize = getpagesize();
+        if (!strcmp(field, "Private_Dirty:")) {
+            return (size_t)pri.pri_pages_dirtied * pagesize;
+        } else if (!strcmp(field, "Rss:")) {
+            return (size_t)pri.pri_pages_resident * pagesize;
+        } else if (!strcmp(field, "AnonHugePages:")) {
             return 0;
-	}
+        }
     }
     return 0;
 #endif