memory: remove libnuma dependency

Seastar is currently pulling in all of libnuma to just invoke a single syscall. Additionally since libnuma being LGPL licensed, it's simpler to not include it as a dependency. Replace the call in numaif.h with a direct syscall. I'm assuming that once libnuma was depended on because it was a dependency of hwloc, however, hwloc version 2 removed the dependency on libnuma, so Seastar can too: https://github.com/open-mpi/hwloc/blob/263908a2c1f21c0e221a8d1f6472daf3a1fc07b9/NEWS#L291
scylladb · Feb 17, 2025 · 56a28fa · 56a28fa
1 parent a3a22eb
commit 56a28fa
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Showing 3 changed files with 26 additions and 14 deletions.
diff --git a/cooking_recipe.cmake b/cooking_recipe.cmake
@@ -110,7 +110,7 @@ cooking_ingredient (nettle
     BUILD_COMMAND <DISABLE>
     INSTALL_COMMAND ${make_command} install)
 
-# Also a direct dependency of Seastar.
+# A dependency of DPDK.
 cooking_ingredient (numactl
   EXTERNAL_PROJECT_ARGS
     URL https://github.com/numactl/numactl/releases/download/v2.0.12/numactl-2.0.12.tar.gz

diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
@@ -127,10 +127,6 @@ target_link_libraries (seastar-module
     yaml-cpp::yaml-cpp
     "$<BUILD_INTERFACE:Valgrind::valgrind>"
     Threads::Threads)
-if (Seastar_NUMA)
-  target_link_libraries (seastar-module
-    PRIVATE numactl::numactl)
-endif ()
 if (Seastar_HWLOC)
   target_link_libraries (seastar-module
     PRIVATE hwloc::hwloc)

diff --git a/src/core/memory.cc b/src/core/memory.cc
@@ -101,10 +101,8 @@ module;
 #include <utility>
 #include <boost/intrusive/list.hpp>
 #include <sys/mman.h>
+#include <sys/syscall.h>
 
-#ifdef SEASTAR_HAVE_NUMA
-#include <numaif.h>
-#endif
 #endif // !defined(SEASTAR_DEFAULT_ALLOCATOR)
 
 #ifdef SEASTAR_MODULE
@@ -1832,6 +1830,23 @@ void configure_minimal() {
     init_cpu_mem();
 }
 
+static long mbind(void *addr,
+                  unsigned long len,
+                  int mode,
+                  const unsigned long *nodemask,
+                  unsigned long maxnode,
+                  unsigned flags) {
+  return syscall(
+    SYS_mbind,
+    reinterpret_cast<long>(addr),
+    len,
+    mode,
+    reinterpret_cast<long>(nodemask),
+    maxnode,
+    flags
+  );
+}
+
 internal::numa_layout
 configure(std::vector<resource::memory> m, bool mbind,
         bool transparent_hugepages,
@@ -1865,16 +1880,18 @@ configure(std::vector<resource::memory> m, bool mbind,
         get_cpu_mem().replace_memory_backing(sys_alloc);
     }
     get_cpu_mem().resize(total, sys_alloc);
-#ifdef SEASTAR_HAVE_NUMA
     size_t pos = 0;
     for (auto&& x : m) {
         unsigned long nodemask = 1UL << x.nodeid;
         if (mbind) {
             auto start = get_cpu_mem().mem() + pos;
-            auto r = ::mbind(start, x.bytes,
-                            MPOL_PREFERRED,
-                            &nodemask, std::numeric_limits<unsigned long>::digits,
-                            MPOL_MF_MOVE);
+            static constexpr int mpol_preferred = 1;
+            static constexpr unsigned int mpol_mf_move = 2;
+            auto r = seastar::memory::mbind(
+                           start, x.bytes,
+                           mpol_preferred,
+                           &nodemask, std::numeric_limits<unsigned long>::digits,
+                           mpol_mf_move);
 
             if (r == -1) {
                 char err[1000] = {};
@@ -1890,7 +1907,6 @@ configure(std::vector<resource::memory> m, bool mbind,
         }
         pos += x.bytes;
     }
-#endif
     return ret_layout;
 }