mm: move page-writeback sysctls to their own file

kernel/sysctl.c is a kitchen sink where everyone leaves their dirty
dishes, this makes it very difficult to maintain.

To help with this maintenance let's start by moving sysctls to places
where they actually belong.  The proc sysctl maintainers do not want to
know what sysctl knobs you wish to add for your own piece of code, we just
care about the core logic.

So move the page-writeback sysctls to its own file.

[akpm@linux-foundation.org: coding-style cleanups]

akpm@linux-foundation.org: fix CONFIG_SYSCTL=n warnings]
Link: https://lkml.kernel.org/r/20220129012955.26594-1-zhanglianjie@uniontech.com
Signed-off-by: zhanglianjie <zhanglianjie@uniontech.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Iurii Zaikin <yzaikin@google.com>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>

1 files changed, 0 insertions, 69 deletions

diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index a21c0ea396f3..36bfe1c92d44 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -100,8 +100,6 @@
 static const int six_hundred_forty_kb = 640 * 1024;
 #endif
 
-/* this is needed for the proc_doulongvec_minmax of vm_dirty_bytes */
-static const unsigned long dirty_bytes_min = 2 * PAGE_SIZE;
 
 static const int ngroups_max = NGROUPS_MAX;
 static const int cap_last_cap = CAP_LAST_CAP;
@@ -2264,55 +2262,6 @@ static struct ctl_table vm_table[] = {
 		.extra1		= SYSCTL_ZERO,
 	},
 	{
-		.procname	= "dirty_background_ratio",
-		.data		= &dirty_background_ratio,
-		.maxlen		= sizeof(dirty_background_ratio),
-		.mode		= 0644,
-		.proc_handler	= dirty_background_ratio_handler,
-		.extra1		= SYSCTL_ZERO,
-		.extra2		= SYSCTL_ONE_HUNDRED,
-	},
-	{
-		.procname	= "dirty_background_bytes",
-		.data		= &dirty_background_bytes,
-		.maxlen		= sizeof(dirty_background_bytes),
-		.mode		= 0644,
-		.proc_handler	= dirty_background_bytes_handler,
-		.extra1		= SYSCTL_LONG_ONE,
-	},
-	{
-		.procname	= "dirty_ratio",
-		.data		= &vm_dirty_ratio,
-		.maxlen		= sizeof(vm_dirty_ratio),
-		.mode		= 0644,
-		.proc_handler	= dirty_ratio_handler,
-		.extra1		= SYSCTL_ZERO,
-		.extra2		= SYSCTL_ONE_HUNDRED,
-	},
-	{
-		.procname	= "dirty_bytes",
-		.data		= &vm_dirty_bytes,
-		.maxlen		= sizeof(vm_dirty_bytes),
-		.mode		= 0644,
-		.proc_handler	= dirty_bytes_handler,
-		.extra1		= (void *)&dirty_bytes_min,
-	},
-	{
-		.procname	= "dirty_writeback_centisecs",
-		.data		= &dirty_writeback_interval,
-		.maxlen		= sizeof(dirty_writeback_interval),
-		.mode		= 0644,
-		.proc_handler	= dirty_writeback_centisecs_handler,
-	},
-	{
-		.procname	= "dirty_expire_centisecs",
-		.data		= &dirty_expire_interval,
-		.maxlen		= sizeof(dirty_expire_interval),
-		.mode		= 0644,
-		.proc_handler	= proc_dointvec_minmax,
-		.extra1		= SYSCTL_ZERO,
-	},
-	{
 		.procname	= "dirtytime_expire_seconds",
 		.data		= &dirtytime_expire_interval,
 		.maxlen		= sizeof(dirtytime_expire_interval),
@@ -2484,13 +2433,6 @@ static struct ctl_table vm_table[] = {
 	},
 #endif
 	{
-		.procname	= "laptop_mode",
-		.data		= &laptop_mode,
-		.maxlen		= sizeof(laptop_mode),
-		.mode		= 0644,
-		.proc_handler	= proc_dointvec_jiffies,
-	},
-	{
 		.procname	= "vfs_cache_pressure",
 		.data		= &sysctl_vfs_cache_pressure,
 		.maxlen		= sizeof(sysctl_vfs_cache_pressure),
@@ -2587,17 +2529,6 @@ static struct ctl_table vm_table[] = {
 		.extra1		= SYSCTL_ZERO,
 	},
 #endif
-#ifdef CONFIG_HIGHMEM
-	{
-		.procname	= "highmem_is_dirtyable",
-		.data		= &vm_highmem_is_dirtyable,
-		.maxlen		= sizeof(vm_highmem_is_dirtyable),
-		.mode		= 0644,
-		.proc_handler	= proc_dointvec_minmax,
-		.extra1		= SYSCTL_ZERO,
-		.extra2		= SYSCTL_ONE,
-	},
-#endif
 #ifdef CONFIG_MEMORY_FAILURE
 	{
 		.procname	= "memory_failure_early_kill",