package/irqbalance: use pkg-config to find numa

Use pkg-config to find numa to avoid the following build failure when
checking for numa_available:

configure:9667: checking for numa_available in -lnuma
configure:9692: /tmp/instance-7/output-1/host/bin/microblazeel-linux-gcc -o conftest -D_LARGEFILE_SOURCE -D_LARGEFILE64_SOURCE -D_FILE_OFFSET_BITS=64  -Os   -static -D_LARGEFILE_SOURCE -D_LARGEFILE64_SOURCE -D_FILE_OFFSET_BITS=64  -static conftest.c -lnuma   >&5
/tmp/instance-7/output-1/host/opt/ext-toolchain/bin/../lib/gcc/microblazeel-buildroot-linux-uclibc/9.3.0/../../../../microblazeel-buildroot-linux-uclibc/bin/ld: /tmp/instance-7/output-1/host/microblazeel-buildroot-linux-uclibc/sysroot/usr/lib/libnuma.a(libnuma.o): in function `numa_node_to_cpus_v1':
(.text+0x2a80): undefined reference to `__atomic_fetch_and_1'
/tmp/instance-7/output-1/host/opt/ext-toolchain/bin/../lib/gcc/microblazeel-buildroot-linux-uclibc/9.3.0/../../../../microblazeel-buildroot-linux-uclibc/bin/ld: /tmp/instance-7/output-1/host/microblazeel-buildroot-linux-uclibc/sysroot/usr/lib/libnuma.a(libnuma.o): in function `numa_node_to_cpus_v2':
(.text+0x2ddc): undefined reference to `__atomic_fetch_and_1'
collect2: error: ld returned 1 exit status

Fixes:
 - http://autobuild.buildroot.org/results/577a63432fba2f9ae1ed2c6c2a77c5ce54ac5521

Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
Signed-off-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>

package/irqbalance/0002-configure.ac-use-pkg-config-to-find-numa.patch

@@ -0,0 +1,38 @@
+From 274cb8ea470a10ce46b783e77784b0eb08cf20d8 Mon Sep 17 00:00:00 2001
+From: Fabrice Fontaine <fontaine.fabrice@gmail.com>
+Date: Sun, 1 Aug 2021 23:26:01 +0200
+Subject: [PATCH] configure.ac: use pkg-config to find numa
+
+Use pkg-config to find numa and fallback to current mechanism.
+Thanks to pkg-config, numa dependencies such as -latomic will be
+retrieved.
+
+Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
+[Upstream status: https://github.com/Irqbalance/irqbalance/pull/188]
+---
+ configure.ac | 9 ++++++++-
+ 1 file changed, 8 insertions(+), 1 deletion(-)
+
+diff --git a/configure.ac b/configure.ac
+index c45b9ce..50c62ba 100644
+--- a/configure.ac
++++ b/configure.ac
+@@ -23,7 +23,14 @@ AC_CHECK_HEADERS([numa.h])
+ 
+ AC_CHECK_FUNCS(getopt_long)
+ 
+-AC_CHECK_LIB(numa, numa_available)
++PKG_CHECK_MODULES([NUMA], [numa], [has_numa=yes], [AC_CHECK_LIB(numa, numa_available)])
++AS_IF([test "x$has_numa" = "xyes"], [
++  AC_SUBST([NUMA_CFLAGS])
++  AC_SUBST([NUMA_LIBS])
++  LIBS="$LIBS $NUMA_LIBS"
++  AC_SUBST([LIBS])
++])
++
+ AC_CHECK_LIB(m, floor)
+ 
+ PKG_CHECK_MODULES([GLIB2], [glib-2.0], [], [AC_MSG_ERROR([glib-2.0 is required])])
+-- 
+2.30.2
+