[PATCH v4 1/2] sysctl clean up vm related variable declarations

From: KAMEZAWA Hiroyuki
Date: Wed Jan 27 2010 - 01:36:00 EST


From: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx>

Now, there are many "extern" declaration in kernel/sysctl.c. "extern"
declaration in *.c file is not appreciated in general.
And Hmm...it seems there are a few redundant declarations.

Because most of sysctl variables are defined in its own header file,
they should be declared in the same style, be done in its own *.h file.

This patch removes some VM(memory management) related sysctl's
variable declaration from kernel/sysctl.c and move them to
proper places.

Change log:
- 2010/01/27 (new)

Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx>
---
include/linux/mm.h | 5 +++++
include/linux/mmzone.h | 1 +
include/linux/oom.h | 5 +++++
kernel/sysctl.c | 16 ++--------------
mm/mmap.c | 5 +++++
5 files changed, 18 insertions(+), 14 deletions(-)

Index: mmotm-2.6.33-Jan15-2/include/linux/mm.h
===================================================================
--- mmotm-2.6.33-Jan15-2.orig/include/linux/mm.h
+++ mmotm-2.6.33-Jan15-2/include/linux/mm.h
@@ -1432,6 +1432,7 @@ int in_gate_area_no_task(unsigned long a
#define in_gate_area(task, addr) ({(void)task; in_gate_area_no_task(addr);})
#endif /* __HAVE_ARCH_GATE_AREA */

+extern int sysctl_drop_caches;
int drop_caches_sysctl_handler(struct ctl_table *, int,
void __user *, size_t *, loff_t *);
unsigned long shrink_slab(unsigned long scanned, gfp_t gfp_mask,
@@ -1476,5 +1477,9 @@ extern int soft_offline_page(struct page

extern void dump_page(struct page *page);

+#ifndef CONFIG_NOMMU
+extern int sysctl_nr_trim_pages;
+#endif
+
#endif /* __KERNEL__ */
#endif /* _LINUX_MM_H */
Index: mmotm-2.6.33-Jan15-2/include/linux/mmzone.h
===================================================================
--- mmotm-2.6.33-Jan15-2.orig/include/linux/mmzone.h
+++ mmotm-2.6.33-Jan15-2/include/linux/mmzone.h
@@ -747,6 +747,7 @@ int min_free_kbytes_sysctl_handler(struc
extern int sysctl_lowmem_reserve_ratio[MAX_NR_ZONES-1];
int lowmem_reserve_ratio_sysctl_handler(struct ctl_table *, int,
void __user *, size_t *, loff_t *);
+extern int percpu_pagelist_fraction; /* for sysctl */
int percpu_pagelist_fraction_sysctl_handler(struct ctl_table *, int,
void __user *, size_t *, loff_t *);
int sysctl_min_unmapped_ratio_sysctl_handler(struct ctl_table *, int,
Index: mmotm-2.6.33-Jan15-2/kernel/sysctl.c
===================================================================
--- mmotm-2.6.33-Jan15-2.orig/kernel/sysctl.c
+++ mmotm-2.6.33-Jan15-2/kernel/sysctl.c
@@ -51,6 +51,8 @@
#include <linux/slow-work.h>
#include <linux/perf_event.h>
#include <linux/rcustring.h>
+#include <linux/mman.h>
+#include <linux/oom.h>

#include <asm/uaccess.h>
#include <asm/processor.h>
@@ -67,11 +69,6 @@
/* External variables not in a header file. */
extern int C_A_D;
extern int print_fatal_signals;
-extern int sysctl_overcommit_memory;
-extern int sysctl_overcommit_ratio;
-extern int sysctl_panic_on_oom;
-extern int sysctl_oom_kill_allocating_task;
-extern int sysctl_oom_dump_tasks;
extern int max_threads;
extern int core_uses_pid;
extern int suid_dumpable;
@@ -80,14 +77,9 @@ extern unsigned int core_pipe_limit;
extern int pid_max;
extern int min_free_kbytes;
extern int pid_max_min, pid_max_max;
-extern int sysctl_drop_caches;
-extern int percpu_pagelist_fraction;
extern int compat_log;
extern int latencytop_enabled;
extern int sysctl_nr_open_min, sysctl_nr_open_max;
-#ifndef CONFIG_MMU
-extern int sysctl_nr_trim_pages;
-#endif
#ifdef CONFIG_RCU_TORTURE_TEST
extern int rcutorture_runnable;
#endif /* #ifdef CONFIG_RCU_TORTURE_TEST */
@@ -198,10 +190,6 @@ extern struct ctl_table inotify_table[];
extern struct ctl_table epoll_table[];
#endif

-#ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
-int sysctl_legacy_va_layout;
-#endif
-
extern int prove_locking;
extern int lock_stat;

Index: mmotm-2.6.33-Jan15-2/include/linux/oom.h
===================================================================
--- mmotm-2.6.33-Jan15-2.orig/include/linux/oom.h
+++ mmotm-2.6.33-Jan15-2/include/linux/oom.h
@@ -43,5 +43,10 @@ static inline void oom_killer_enable(voi
{
oom_killer_disabled = false;
}
+/* for sysctl */
+extern int sysctl_panic_on_oom;
+extern int sysctl_oom_kill_allocating_task;
+extern int sysctl_oom_dump_tasks;
+
#endif /* __KERNEL__*/
#endif /* _INCLUDE_LINUX_OOM_H */
Index: mmotm-2.6.33-Jan15-2/mm/mmap.c
===================================================================
--- mmotm-2.6.33-Jan15-2.orig/mm/mmap.c
+++ mmotm-2.6.33-Jan15-2/mm/mmap.c
@@ -87,6 +87,11 @@ int sysctl_overcommit_ratio = 50; /* def
int sysctl_max_map_count __read_mostly = DEFAULT_MAX_MAP_COUNT;
struct percpu_counter vm_committed_as;

+#ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
+/* Used by each architecture's private code and sysctl. */
+int sysctl_legacy_va_layout;
+#endif
+
/*
* Check that a process has enough memory to allocate a new virtual
* mapping. 0 means there is enough memory for the allocation to

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