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-rw-r--r--erts/emulator/test/scheduler_SUITE.erl133
1 files changed, 133 insertions, 0 deletions
diff --git a/erts/emulator/test/scheduler_SUITE.erl b/erts/emulator/test/scheduler_SUITE.erl
index 4f4458802c..06442bfad6 100644
--- a/erts/emulator/test/scheduler_SUITE.erl
+++ b/erts/emulator/test/scheduler_SUITE.erl
@@ -47,6 +47,7 @@
scheduler_bind/1,
scheduler_bind_types/1,
cpu_topology/1,
+ update_cpu_info/1,
sct_cmd/1,
sbt_cmd/1,
scheduler_suspend/1,
@@ -249,6 +250,7 @@ bound_loop(NS, N, M, Sched) ->
scheduler_bind(suite) ->
[scheduler_bind_types,
cpu_topology,
+ update_cpu_info,
sct_cmd,
sbt_cmd].
@@ -772,6 +774,137 @@ cpu_topology_cmdline_test(Config, Topology, Cmd) ->
?line stop_node(Node),
?line ok.
+update_cpu_info(Config) when is_list(Config) ->
+ ?line OldOnline = erlang:system_info(schedulers_online),
+ ?line OldAff = get_affinity_mask(),
+ ?line ?t:format("START - Affinity mask: ~p - Schedulers online: ~p - Scheduler bindings: ~p~n",
+ [OldAff, OldOnline, erlang:system_info(scheduler_bindings)]),
+ ?line case {erlang:system_info(logical_processors_available), OldAff} of
+ {Avail, _} when Avail == unknown; OldAff == unknown ->
+ %% Nothing much to test; just a smoke test
+ case erlang:system_info(update_cpu_info) of
+ unchanged -> ?line ok;
+ changed -> ?line ok
+ end;
+ _ ->
+ try
+ ?line adjust_schedulers_online(),
+ case erlang:system_info(schedulers_online) of
+ 1 ->
+ %% Nothing much to test; just a smoke test
+ ?line ok;
+ Onln0 ->
+ %% unset least significant bit
+ ?line Aff = (OldAff band (OldAff - 1)),
+ ?line set_affinity_mask(Aff),
+ ?line Onln1 = Onln0 - 1,
+ ?line case adjust_schedulers_online() of
+ {Onln0, Onln1} ->
+ ?line Onln1 = erlang:system_info(schedulers_online),
+ ?line receive after 500 -> ok end,
+ ?line ?t:format("TEST - Affinity mask: ~p - Schedulers online: ~p - Scheduler bindings: ~p~n",
+ [Aff, Onln1, erlang:system_info(scheduler_bindings)]),
+ ?line unchanged = adjust_schedulers_online(),
+ ?line ok;
+ Fail ->
+ ?line ?t:fail(Fail)
+ end
+ end
+ after
+ set_affinity_mask(OldAff),
+ adjust_schedulers_online(),
+ erlang:system_flag(schedulers_online, OldOnline),
+ receive after 500 -> ok end,
+ ?t:format("END - Affinity mask: ~p - Schedulers online: ~p - Scheduler bindings: ~p~n",
+ [get_affinity_mask(),
+ erlang:system_info(schedulers_online),
+ erlang:system_info(scheduler_bindings)])
+ end
+ end.
+
+adjust_schedulers_online() ->
+ case erlang:system_info(update_cpu_info) of
+ unchanged ->
+ unchanged;
+ changed ->
+ Avail = erlang:system_info(logical_processors_available),
+ {erlang:system_flag(schedulers_online, Avail), Avail}
+ end.
+
+read_affinity(Data) ->
+ Exp = "pid " ++ os:getpid() ++ "'s current affinity mask",
+ case string:tokens(Data, ":") of
+ [Exp, DirtyAffinityStr] ->
+ AffinityStr = string:strip(string:strip(DirtyAffinityStr,
+ both, $ ),
+ both, $\n),
+ case catch erlang:list_to_integer(AffinityStr, 16) of
+ Affinity when is_integer(Affinity) ->
+ Affinity;
+ _ ->
+ bad
+ end;
+ _ ->
+ bad
+ end.
+
+get_affinity_mask(Port, Status, Affinity) when Status == unknown;
+ Affinity == unknown ->
+ receive
+ {Port,{data, Data}} ->
+ get_affinity_mask(Port, Status, read_affinity(Data));
+ {Port,{exit_status,S}} ->
+ get_affinity_mask(Port, S, Affinity)
+ end;
+get_affinity_mask(Port, Status, bad) ->
+ unknown;
+get_affinity_mask(Port, Status, Affinity) ->
+ Affinity.
+
+get_affinity_mask() ->
+ case ?t:os_type() of
+ {unix, linux} ->
+ case catch open_port({spawn, "taskset -p " ++ os:getpid()},
+ [exit_status]) of
+ Port when is_port(Port) ->
+ get_affinity_mask(Port, unknown, unknown);
+ _ ->
+ unknown
+ end;
+ _ ->
+ unknown
+ end.
+
+set_affinity_mask(Port, unknown) ->
+ receive
+ {Port,{data, _}} ->
+ set_affinity_mask(Port, unknown);
+ {Port,{exit_status,Status}} ->
+ set_affinity_mask(Port, Status)
+ end;
+set_affinity_mask(Port, Status) ->
+ receive
+ {Port,{data, _}} ->
+ set_affinity_mask(Port, unknown)
+ after 0 ->
+ Status
+ end.
+
+set_affinity_mask(Mask) ->
+ Cmd = lists:flatten(["taskset -p ",
+ io_lib:format("~.16b", [Mask]),
+ " ",
+ os:getpid()]),
+ case catch open_port({spawn, Cmd}, [exit_status]) of
+ Port when is_port(Port) ->
+ case set_affinity_mask(Port, unknown) of
+ 0 -> ok;
+ _ -> exit(failed_to_set_affinity)
+ end;
+ _ ->
+ exit(failed_to_set_affinity)
+ end.
+
sct_cmd(Config) when is_list(Config) ->
?line Topology = ?TOPOLOGY_A_TERM,
?line OldRelFlags = clear_erl_rel_flags(),