lib/Makefile: make union-find compilation conditional on CONFIG_CPUSETS

Currently, cpuset is the only user of the union-find implementation.
Compiling union-find in all configurations unnecessarily increases the
code size when building the kernel without cgroup support.  Modify the
build system to compile union-find only when CONFIG_CPUSETS is enabled.

Link: https://lore.kernel.org/lkml/1ccd6411-5002-4574-bb8e-3e64bba6a757@redhat.com/
Link: https://lkml.kernel.org/r/20241011141214.87096-1-visitorckw@gmail.com
Signed-off-by: Kuan-Wei Chiu <visitorckw@gmail.com>
Suggested-by: Waiman Long <llong@redhat.com>
Acked-by: Waiman Long <longman@redhat.com>
Acked-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Ching-Chun (Jim) Huang <jserv@ccns.ncku.edu.tw>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Koutný <mkoutny@suse.com>
Cc: Xavier <xavier_qy@163.com>
Cc: Zefan Li <lizefan.x@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/init/Kconfig b/init/Kconfig
index c521e14..5cb9b94 100644 (file)
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -1157,6 +1157,7 @@ config CGROUP_HUGETLB
 config CPUSETS
        bool "Cpuset controller"
        depends on SMP
+       select UNION_FIND
        help
          This option will let you create and manage CPUSETs which
          allow dynamically partitioning a system into sets of CPUs and

diff --git a/lib/Kconfig b/lib/Kconfig
index b38849a..cf303bd 100644 (file)
--- a/lib/Kconfig
+++ b/lib/Kconfig
@@ -777,3 +777,6 @@ config POLYNOMIAL
 
 config FIRMWARE_TABLE
        bool
+
+config UNION_FIND
+       bool

diff --git a/lib/Makefile b/lib/Makefile
index 1faed64..feebed7 100644 (file)
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -35,8 +35,9 @@ lib-y := ctype.o string.o vsprintf.o cmdline.o \
         is_single_threaded.o plist.o decompress.o kobject_uevent.o \
         earlycpio.o seq_buf.o siphash.o dec_and_lock.o \
         nmi_backtrace.o win_minmax.o memcat_p.o \
-        buildid.o objpool.o union_find.o
+        buildid.o objpool.o
 
+lib-$(CONFIG_UNION_FIND) += union_find.o
 lib-$(CONFIG_PRINTK) += dump_stack.o
 lib-$(CONFIG_SMP) += cpumask.o