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

(cherry picked from commit 8ab0267)

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

src/CMakeLists.txt

@@ -130,10 +130,6 @@ 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)

src/core/memory.cc

@@ -101,10 +101,9 @@ module;
 #include <utility>
 #include <boost/intrusive/list.hpp>
 #include <sys/mman.h>
+#include <sys/syscall.h>
+#include <linux/mempolicy.h>
 
-#ifdef SEASTAR_HAVE_NUMA
-#include <numaif.h>
-#endif
 #endif // !defined(SEASTAR_DEFAULT_ALLOCATOR)
 
 #ifdef SEASTAR_MODULE
@@ -1832,6 +1831,23 @@ 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,
+        addr,
+        len,
+        mode,
+        nodemask,
+        maxnode,
+        flags
+    );
+}
+
 internal::numa_layout
 configure(std::vector<resource::memory> m, bool mbind,
         bool transparent_hugepages,
@@ -1865,13 +1881,13 @@ 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,
+            auto r = seastar::memory::mbind(
+                            start, x.bytes,
                             MPOL_PREFERRED,
                             &nodemask, std::numeric_limits<unsigned long>::digits,
                             MPOL_MF_MOVE);
@@ -1890,7 +1906,6 @@ configure(std::vector<resource::memory> m, bool mbind,
         }
         pos += x.bytes;
     }
-#endif
     return ret_layout;
 }