remove restriction on number of threads

Closes #36469
JuliaLang · Jul 23, 2020 · 149af56 · 149af56
1 parent 34b2ae5
commit 149af56
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Showing 2 changed files with 15 additions and 16 deletions.
diff --git a/src/threading.c b/src/threading.c
@@ -406,16 +406,13 @@ void jl_init_threading(void)
 #endif
 
     // how many threads available, usable
-    int max_threads = jl_cpu_threads();
     jl_n_threads = JULIA_NUM_THREADS;
     if (jl_options.nthreads < 0) // --threads=auto
-        jl_n_threads = max_threads;
+        jl_n_threads = jl_cpu_threads();
     else if (jl_options.nthreads > 0) // --threads=N
         jl_n_threads = jl_options.nthreads;
     else if ((cp = getenv(NUM_THREADS_NAME)))
         jl_n_threads = (uint64_t)strtol(cp, NULL, 10);
-    if (jl_n_threads > max_threads)
-        jl_n_threads = max_threads;
     if (jl_n_threads <= 0)
         jl_n_threads = 1;
 #ifndef __clang_analyzer__

diff --git a/test/cmdlineargs.jl b/test/cmdlineargs.jl
@@ -190,29 +190,31 @@ let exename = `$(Base.julia_cmd()) --startup-file=no`
 
     # -t, --threads
     code = "print(Threads.nthreads())"
-    cpu_threads = ccall(:jl_cpu_threads, Int32, ())
-    @test string(cpu_threads) ==
+    cpu_threads = string(ccall(:jl_cpu_threads, Int32, ()))
+    @test cpu_threads ==
           read(`$exename --threads auto -e $code`, String) ==
           read(`$exename --threads=auto -e $code`, String) ==
           read(`$exename -tauto -e $code`, String) ==
-          read(`$exename -t auto -e $code`, String) ==
-          read(`$exename -t $(cpu_threads+1) -e $code`, String)
-    if cpu_threads > 1
-        for nt in (nothing, "1"); withenv("JULIA_NUM_THREADS"=>nt) do
-            @test read(`$exename --threads 2 -e $code`, String) ==
-                  read(`$exename --threads=2 -e $code`, String) ==
-                  read(`$exename -t2 -e $code`, String) ==
+          read(`$exename -t auto -e $code`, String)
+    for nt in (nothing, "1")
+        withenv("JULIA_NUM_THREADS" => nt) do
+            @test read(`$exename --threads=2 -e $code`, String) ==
                   read(`$exename -t 2 -e $code`, String) == "2"
-        end end
+        end
+    end
+    cpu_threads *= "0"
+    @test read(`$exename -t $cpu_threads -e $code`, String) == cpu_threads
+    withenv("JULIA_NUM_THREADS" => cpu_threads) do
+        @test read(`$exename -e $code`, String) == cpu_threads
     end
     @test !success(`$exename -t 0`)
     @test !success(`$exename -t -1`)
 
     # Combining --threads and --procs: --threads does propagate
-    if cpu_threads > 1; withenv("JULIA_NUM_THREADS"=>nothing) do
+    withenv("JULIA_NUM_THREADS" => nothing) do
         code = "print(sum(remotecall_fetch(Threads.nthreads, x) for x in procs()))"
         @test read(`$exename -p2 -t2 -e $code`, String) == "6"
-    end end
+    end
 
     # --procs
     @test readchomp(`$exename -q -p 2 -e "println(nworkers())"`) == "2"