Simplify numasupport (dotnet#84207)

* Simplify numasupport

* short-circuit

* Cleanup from QUIC readme

* Address CR feedback: early bail for < 2 NUMA nodes

* Fix node numbering, which is 0-based

.devcontainer/libraries/Dockerfile

@@ -23,7 +23,6 @@ RUN apt-get update && export DEBIAN_FRONTEND=noninteractive \
         libicu-dev \
         liblttng-ust-dev \
         libssl-dev \
-        libnuma-dev \
         libkrb5-dev \
         zlib1g-dev \
         ninja-build

.devcontainer/wasm/Dockerfile

@@ -23,7 +23,6 @@ RUN apt-get update && export DEBIAN_FRONTEND=noninteractive \
         libicu-dev \
         liblttng-ust-dev \
         libssl-dev \
-        libnuma-dev \
         libkrb5-dev \
         zlib1g-dev \
         ninja-build

docs/workflow/requirements/linux-requirements.md

@@ -37,14 +37,13 @@ Install the following packages for the toolchain:
 * liblttng-ust-dev
 * libssl-dev
 * libkrb5-dev
-* libnuma-dev (optional, enables numa support)
 * zlib1g-dev
 * ninja-build (optional, enables building native code with ninja instead of make)
 
 ```bash
 sudo apt install -y cmake llvm lld clang build-essential \
 python-is-python3 curl git lldb libicu-dev liblttng-ust-dev \
-libssl-dev libnuma-dev libkrb5-dev zlib1g-dev ninja-build
+libssl-dev libkrb5-dev zlib1g-dev ninja-build
 ```
 
 You now have all the required components.

eng/install-native-dependencies.sh

@@ -28,7 +28,7 @@ case "$os" in
         apt update
 
         apt install -y build-essential gettext locales cmake llvm clang lldb liblldb-dev libunwind8-dev libicu-dev liblttng-ust-dev \
-            libssl-dev libkrb5-dev libnuma-dev zlib1g-dev
+            libssl-dev libkrb5-dev zlib1g-dev
 
         localedef -i en_US -c -f UTF-8 -A /usr/share/locale/locale.alias en_US.UTF-8
         ;;

src/coreclr/gc/unix/CMakeLists.txt

@@ -5,7 +5,7 @@ include(configure.cmake)
 
 set(GC_PAL_SOURCES
     gcenv.unix.cpp
-    numasupport.dynamic.cpp
+    numasupport.cpp
     events.cpp
     cgroup.cpp)
 

src/coreclr/gc/unix/config.gc.h.in

@@ -11,7 +11,6 @@
 #cmakedefine01 HAVE_VM_FLAGS_SUPERPAGE_SIZE_ANY
 #cmakedefine01 HAVE_MAP_HUGETLB
 #cmakedefine01 HAVE_SCHED_GETCPU
-#cmakedefine01 HAVE_NUMA_H
 #cmakedefine01 HAVE_VM_ALLOCATE
 #cmakedefine01 HAVE_SWAPCTL
 #cmakedefine01 HAVE_SYSCTLBYNAME

src/coreclr/gc/unix/configure.cmake

@@ -10,7 +10,6 @@ include(CheckLibraryExists)
 
 check_include_files(sys/time.h HAVE_SYS_TIME_H)
 check_include_files(sys/mman.h HAVE_SYS_MMAN_H)
-check_include_files(numa.h HAVE_NUMA_H)
 check_include_files(pthread_np.h HAVE_PTHREAD_NP_H)
 
 check_function_exists(vm_allocate HAVE_VM_ALLOCATE)

src/coreclr/gc/unix/gcenv.unix.cpp

@@ -318,7 +318,6 @@ void GCToOSInterface::Shutdown()
     munmap(g_helperPage, OS_PAGE_SIZE);
 
     CleanupCGroup();
-    NUMASupportCleanup();
 }
 
 // Get numeric id of the current thread if possible on the
@@ -615,7 +614,7 @@ bool GCToOSInterface::VirtualCommit(void* address, size_t size, uint16_t node)
     }
 #endif
 
-#if HAVE_NUMA_H
+#ifdef TARGET_LINUX
     if (success && g_numaAvailable && (node != NUMA_NODE_UNDEFINED))
     {
         if ((int)node <= g_highestNumaNode)
@@ -628,12 +627,12 @@ bool GCToOSInterface::VirtualCommit(void* address, size_t size, uint16_t node)
             int index = node / sizeof(unsigned long);
             nodeMask[index] = ((unsigned long)1) << (node & (sizeof(unsigned long) - 1));
 
-            int st = mbind(address, size, MPOL_PREFERRED, nodeMask, usedNodeMaskBits, 0);
+            int st = BindMemoryPolicy(address, size, nodeMask, usedNodeMaskBits);
             assert(st == 0);
             // If the mbind fails, we still return the allocated memory since the node is just a hint
         }
     }
-#endif // HAVE_NUMA_H
+#endif // TARGET_LINUX
 
     return success;
 }
@@ -1430,14 +1429,14 @@ bool GCToOSInterface::GetProcessorForHeap(uint16_t heap_number, uint16_t* proc_n
             if (availableProcNumber == heap_number)
             {
                 *proc_no = procNumber;
-#if HAVE_NUMA_H
+#ifdef TARGET_LINUX
                 if (GCToOSInterface::CanEnableGCNumaAware())
                 {
-                    int result = numa_node_of_cpu(procNumber);
+                    int result = GetNumaNodeNumByCpu(procNumber);
                     *node_no = (result >= 0) ? (uint16_t)result : NUMA_NODE_UNDEFINED;
                 }
                 else
-#endif // HAVE_NUMA_H
+#endif // TARGET_LINUX
                 {
                     *node_no = NUMA_NODE_UNDEFINED;
                 }

src/coreclr/gc/unix/numasupport.cpp

@@ -0,0 +1,86 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+#include "numasupport.h"
+
+#include <stdlib.h>
+#include <unistd.h>
+#include <errno.h>
+#include <stdio.h>
+#include <dirent.h>
+#include <string.h>
+#include <sys/syscall.h>
+#include <minipal/utils.h>
+
+// The highest NUMA node available
+int g_highestNumaNode = 0;
+// Is numa available
+bool g_numaAvailable = false;
+
+#ifdef TARGET_LINUX
+static int GetNodeNum(const char* path, bool firstOnly)
+{
+    DIR *dir;
+    struct dirent *entry;
+    int result = -1;
+
+    dir = opendir(path);
+    if (dir)
+    {
+        while ((entry = readdir(dir)) != NULL)
+        {
+            if (strncmp(entry->d_name, "node", STRING_LENGTH("node")))
+                continue;
+
+            int nodeNum = strtoul(entry->d_name + STRING_LENGTH("node"), NULL, 0);
+            if (result < nodeNum)
+                result = nodeNum;
+
+            if (firstOnly)
+                break;
+        }
+
+        closedir(dir);
+    }
+
+    return result;
+}
+#endif
+
+void NUMASupportInitialize()
+{
+#ifdef TARGET_LINUX
+    if (syscall(__NR_get_mempolicy, NULL, NULL, 0, 0, 0) < 0 && errno == ENOSYS)
+        return;
+
+    int highestNumaNode = GetNodeNum("/sys/devices/system/node", false);
+    // we only use this implementation when there are two or more NUMA nodes available
+    if (highestNumaNode < 1)
+        return;
+
+    g_numaAvailable = true;
+    g_highestNumaNode = highestNumaNode;
+#endif
+}
+
+int GetNumaNodeNumByCpu(int cpu)
+{
+#ifdef TARGET_LINUX
+    char path[64];
+    if (snprintf(path, sizeof(path), "/sys/devices/system/cpu/cpu%d", cpu) < 0)
+        return -1;
+
+    return GetNodeNum(path, true);
+#else
+    return -1;
+#endif
+}
+
+long BindMemoryPolicy(void* start, unsigned long len, const unsigned long* nodemask, unsigned long maxnode)
+{
+#ifdef TARGET_LINUX
+    return syscall(__NR_mbind, (long)start, len, 1, (long)nodemask, maxnode, 0);
+#else
+    return -1;
+#endif
+}

src/coreclr/gc/unix/numasupport.h

@@ -4,39 +4,8 @@
 #ifndef __NUMASUPPORT_H__
 #define __NUMASUPPORT_H__
 
-#include "config.gc.h"
-
-#if HAVE_NUMA_H
-
-#include <numa.h>
-#include <numaif.h>
-
-#endif // HAVE_NUMA_H
-
 void NUMASupportInitialize();
-void NUMASupportCleanup();
-
-#if HAVE_NUMA_H
-
-// List of all functions from the numa library that are used
-#define FOR_ALL_NUMA_FUNCTIONS \
-    PER_FUNCTION_BLOCK(mbind) \
-    PER_FUNCTION_BLOCK(numa_available) \
-    PER_FUNCTION_BLOCK(numa_max_node) \
-    PER_FUNCTION_BLOCK(numa_node_of_cpu)
-
-// Declare pointers to all the used numa functions
-#define PER_FUNCTION_BLOCK(fn) extern decltype(fn)* fn##_ptr;
-FOR_ALL_NUMA_FUNCTIONS
-#undef PER_FUNCTION_BLOCK
-
-// Redefine all calls to numa functions as calls through pointers that are set
-// to the functions of libnuma in the initialization.
-#define mbind(...) mbind_ptr(__VA_ARGS__)
-#define numa_available() numa_available_ptr()
-#define numa_max_node() numa_max_node_ptr()
-#define numa_node_of_cpu(...) numa_node_of_cpu_ptr(__VA_ARGS__)
-
-#endif // HAVE_NUMA_H
+int GetNumaNodeNumByCpu(int cpu);
+long BindMemoryPolicy(void* start, unsigned long len, const unsigned long* nodemask, unsigned long maxnode);
 
 #endif // __NUMASUPPORT_H__