Make CpuInfo::get_current_core work

be/CMakeLists.txt

@@ -287,6 +287,14 @@ execute_process(
   OUTPUT_VARIABLE LLVM_MODULE_LIBS
   OUTPUT_STRIP_TRAILING_WHITESPACE
 )
+
+# Check if functions are supported in this platform. All flags will generated
+# in gensrc/build/common/env_config.h.
+# You can check funcion here which depends on platform. Don't forget add this
+# to be/src/common/env_config.h.in
+include(CheckFunctionExists)
+check_function_exists(sched_getcpu HAVE_SCHED_GETCPU)
+
 # compiler flags that are common across debug/release builds
 #  -Wall: Enable all warnings.
 #  -Wno-sign-compare: suppress warnings for comparison between signed and unsigned
@@ -461,7 +469,6 @@ include_directories(
     ${THIRDPARTY_DIR}/include/event/
 )
 
-
 set(WL_START_GROUP "-Wl,--start-group")
 set(WL_END_GROUP "-Wl,--end-group")
 

be/src/common/CMakeLists.txt

@@ -26,4 +26,5 @@ add_library(Common STATIC
   configbase.cpp
 )
 
-#ADD_BE_TEST(resource_tls_test)
+# Generate env_config.h according to env_config.h.in
+configure_file(${CMAKE_CURRENT_SOURCE_DIR}/env_config.h.in ${GENSRC_DIR}/common/env_config.h)

be/src/common/config.h

@@ -344,8 +344,9 @@ namespace config {
 
     CONF_Bool(enable_prefetch, "true");
 
-    // cpu count
-    CONF_Int32(flags_num_cores, "32");
+    // Number of cores Doris will used, this will effect only when it's greater than 0.
+    // Otherwise, Doris will use all cores returned from "/proc/cpuinfo".
+    CONF_Int32(num_cores, "0");
 
     CONF_Bool(thread_creation_fault_injection, "false");
 

be/src/common/env_config.h.in

@@ -0,0 +1,24 @@
+// Licensed to the Apache Software Foundation (ASF) under one
+// or more contributor license agreements.  See the NOTICE file
+// distributed with this work for additional information
+// regarding copyright ownership.  The ASF licenses this file
+// to you under the Apache License, Version 2.0 (the
+// "License"); you may not use this file except in compliance
+// with the License.  You may obtain a copy of the License at
+//
+//   http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing,
+// software distributed under the License is distributed on an
+// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+// KIND, either express or implied.  See the License for the
+// specific language governing permissions and limitations
+// under the License.
+
+#pragma once
+
+namespace doris {
+
+#cmakedefine HAVE_SCHED_GETCPU @HAVE_SCHED_GETCPU@
+
+}

be/src/util/cpu_info.cpp

@@ -35,6 +35,7 @@
 #include <sys/sysinfo.h>
 
 #include "common/config.h"
+#include "common/env_config.h"
 #include "gflags/gflags.h"
 #include "gutil/strings/substitute.h"
 #include "util/pretty_printer.h"
@@ -156,13 +157,13 @@ void CpuInfo::init() {
   } else {
     num_cores_ = 1;
   }
-  if (config::flags_num_cores > 0) num_cores_ = config::flags_num_cores;
+  if (config::num_cores > 0) num_cores_ = config::num_cores;
   max_num_cores_ = get_nprocs_conf();
 
   // Print a warning if something is wrong with sched_getcpu().
 #ifdef HAVE_SCHED_GETCPU
   if (sched_getcpu() == -1) {
-    LOG(WARNING) << "Kernel does not support getcpu(). Performance may be impacted.";
+    LOG(WARNING) << "Kernel does not support sched_getcpu(). Performance may be impacted.";
   }
 #else
   LOG(WARNING) << "Built on a system without sched_getcpu() support. Performance may"
@@ -284,15 +285,21 @@ void CpuInfo::enable_feature(long flag, bool enable) {
 }
 
 int CpuInfo::get_current_core() {
-  // sched_getcpu() is not supported on some old kernels/glibcs (like the versions that
-  // shipped with CentOS 5). In that case just pretend we're always running on CPU 0
-  // so that we can build and run with degraded perf.
+    // sched_getcpu() is not supported on some old kernels/glibcs (like the versions that
+    // shipped with CentOS 5). In that case just pretend we're always running on CPU 0
+    // so that we can build and run with degraded perf.
 #ifdef HAVE_SCHED_GETCPU
-  int cpu = sched_getcpu();
-  // The syscall may not be supported even if the function exists.
-  return cpu == -1 ? 0 : cpu;
+    int cpu = sched_getcpu();
+    if (cpu < 0) return 0;
+    if (cpu >= max_num_cores_) {
+        LOG_FIRST_N(WARNING, 5) << "sched_getcpu() return value " << cpu
+            << ", which is greater than get_nprocs_conf() retrun value " << max_num_cores_
+            << ", now is " << get_nprocs_conf();
+        cpu %= max_num_cores_;
+    }
+    return cpu;
 #else
-  return 0;
+    return 0;
 #endif
 }