[PATCH] mm: Reduce dependencies on <linux/kernel.h>

[Christophe JAILLET <christophe.jaillet@wanadoo.fr>]

"page_counter.h" does not need <linux/kernel.h>. <linux/limits.h> is enough
to get LONG_MAX.

Files that include page_counter.h are limited. They have been compile
tested or checked.

$ git grep page_counter\.h
include/linux/hugetlb_cgroup.h: struct page_counter hugepage[HUGE_MAX_HSTATE];
	--> all files that include it have been compile tested

include/linux/memcontrol.h:#include <linux/page_counter.h>
	--> <linux/kernel.h> has been added, to be safe

include/net/sock.h:#include <linux/page_counter.h>
	--> already include <linux/kernel.h>

mm/hugetlb_cgroup.c:#include <linux/page_counter.h>
mm/memcontrol.c:#include <linux/page_counter.h>
mm/page_counter.c:#include <linux/page_counter.h>
	--> compile tested

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
---
Let see if build-bots agree with me.
---
 include/linux/memcontrol.h   | 1 +
 include/linux/page_counter.h | 2 +-
 2 files changed, 2 insertions(+), 1 deletion(-)

diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
index 20ff87f8e001..4e4caeaea404 100644
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -14,6 +14,7 @@
 #include <linux/vm_event_item.h>
 #include <linux/hardirq.h>
 #include <linux/jump_label.h>
+#include <linux/kernel.h>
 #include <linux/page_counter.h>
 #include <linux/vmpressure.h>
 #include <linux/eventfd.h>
diff --git a/include/linux/page_counter.h b/include/linux/page_counter.h
index c141ea9a95ef..8cd858d912c4 100644
--- a/include/linux/page_counter.h
+++ b/include/linux/page_counter.h
@@ -4,7 +4,7 @@
 
 #include <linux/atomic.h>
 #include <linux/cache.h>
-#include <linux/kernel.h>
+#include <linux/limits.h>
 #include <asm/page.h>
 
 struct page_counter {
-- 
2.43.0