Make Erlang's cpu_sup function better on Android

Due to `/proc` restrictions in newer Android releases enforced by SELinux, Erlang needs a fix so that it can get some basic CPU stats (use the `sysinfo` syscall rather than reading `/proc/loadavg`).

1 files changed, 15 insertions, 11 deletions

diff --git a/lib/os_mon/src/cpu_sup.erl b/lib/os_mon/src/cpu_sup.erl
index 81e049ef22..ba2d89313e 100644
--- a/lib/os_mon/src/cpu_sup.erl
+++ b/lib/os_mon/src/cpu_sup.erl
@@ -220,17 +220,21 @@ code_change(_OldVsn, State, _Extra) ->
 %% internal functions 
 %%----------------------------------------------------------------------
 
-get_uint32_measurement(Request, #internal{os_type = {unix, linux}}) ->
-    {ok,F} = file:open("/proc/loadavg",[read,raw]),
-    {ok,D} = file:read_line(F),
-    ok = file:close(F),
-    {ok,[Load1,Load5,Load15,_PRun,PTotal],_} = io_lib:fread("~f ~f ~f ~d/~d", D),
-    case Request of
-	?avg1  -> sunify(Load1);
-	?avg5  -> sunify(Load5);
-	?avg15 -> sunify(Load15);
-	?ping -> 4711;
-	?nprocs -> PTotal
+get_uint32_measurement(Request, #internal{port = P, os_type = {unix, linux}}) ->
+    case file:open("/proc/loadavg",[read,raw]) of
+        {ok,F} ->
+            {ok,D} = file:read_line(F),
+            ok = file:close(F),
+            {ok,[Load1,Load5,Load15,_PRun,PTotal],_} = io_lib:fread("~f ~f ~f ~d/~d", D),
+            case Request of
+                ?avg1  -> sunify(Load1);
+                ?avg5  -> sunify(Load5);
+                ?avg15 -> sunify(Load15);
+                ?ping -> 4711;
+                ?nprocs -> PTotal
+            end;
+        {error,_} ->
+            port_server_call(P, Request)
     end;
 get_uint32_measurement(Request, #internal{port = P, os_type = {unix, Sys}}) when
 								Sys == sunos;