mm: remove noisy remainder of the scan_unevictable interface

The deprecation warnings for the scan_unevictable interface triggers by
scripts doing `sysctl -a | grep something else'.  This is annoying and not
helpful.

The interface has been defunct since 264e56d8247e ("mm: disable user
interface to manually rescue unevictable pages"), which was in 2011, and
there haven't been any reports of usecases for it, only reports that the
deprecation warnings are annying.  It's unlikely that anybody is using
this interface specifically at this point, so remove it.

Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/Documentation/ABI/stable/sysfs-devices-node b/Documentation/ABI/stable/sysfs-devices-node
index ce259c13c36a4e716ef6cac9e8436b8c22645088..5b2d0f08867cd899df072f89a059995944fb8eec 100644 (file)
--- a/Documentation/ABI/stable/sysfs-devices-node
+++ b/Documentation/ABI/stable/sysfs-devices-node
@@ -85,14 +85,6 @@ Description:
                will be compacted. When it completes, memory will be freed
                into blocks which have as many contiguous pages as possible
 
-What:          /sys/devices/system/node/nodeX/scan_unevictable_pages
-Date:          October 2008
-Contact:       Lee Schermerhorn <lee.schermerhorn@hp.com>
-Description:
-               When set, it triggers scanning the node's unevictable lists
-               and move any pages that have become evictable onto the respective
-               zone's inactive list. See mm/vmscan.c
-
 What:          /sys/devices/system/node/nodeX/hugepages/hugepages-<size>/
 Date:          December 2009
 Contact:       Lee Schermerhorn <lee.schermerhorn@hp.com>

diff --git a/drivers/base/node.c b/drivers/base/node.c
index d51c49c9bafac65ce4ca0b064fc4c825674dc484..472168cd0c9787a99e7d7d70d4a22cb8bf8680ab 100644 (file)
--- a/drivers/base/node.c
+++ b/drivers/base/node.c
@@ -289,8 +289,6 @@ static int register_node(struct node *node, int num, struct node *parent)
                device_create_file(&node->dev, &dev_attr_distance);
                device_create_file(&node->dev, &dev_attr_vmstat);
 
-               scan_unevictable_register_node(node);
-
                hugetlb_register_node(node);
 
                compaction_register_node(node);
@@ -314,7 +312,6 @@ void unregister_node(struct node *node)
        device_remove_file(&node->dev, &dev_attr_distance);
        device_remove_file(&node->dev, &dev_attr_vmstat);
 
-       scan_unevictable_unregister_node(node);
        hugetlb_unregister_node(node);          /* no-op, if memoryless node */
 
        device_unregister(&node->dev);

diff --git a/include/linux/swap.h b/include/linux/swap.h
index 1b72060f093a6e74bb64d05cecf2d2894f987796..ea4f926e6b9b849588cec2ccde50ec5a80a48e65 100644 (file)
--- a/include/linux/swap.h
+++ b/include/linux/swap.h
@@ -354,22 +354,6 @@ static inline int zone_reclaim(struct zone *z, gfp_t mask, unsigned int order)
 extern int page_evictable(struct page *page);
 extern void check_move_unevictable_pages(struct page **, int nr_pages);
 
-extern unsigned long scan_unevictable_pages;
-extern int scan_unevictable_handler(struct ctl_table *, int,
-                                       void __user *, size_t *, loff_t *);
-#ifdef CONFIG_NUMA
-extern int scan_unevictable_register_node(struct node *node);
-extern void scan_unevictable_unregister_node(struct node *node);
-#else
-static inline int scan_unevictable_register_node(struct node *node)
-{
-       return 0;
-}
-static inline void scan_unevictable_unregister_node(struct node *node)
-{
-}
-#endif
-
 extern int kswapd_run(int nid);
 extern void kswapd_stop(int nid);
 #ifdef CONFIG_MEMCG

diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index 75875a741b5e7f9cb26fcd837609638b1ffafda8..91180987e40e6c6acf88ad2a6e9aab4ea558b1f1 100644 (file)
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -1460,13 +1460,6 @@ static struct ctl_table vm_table[] = {
                .extra2         = &one,
        },
 #endif
-       {
-               .procname       = "scan_unevictable_pages",
-               .data           = &scan_unevictable_pages,
-               .maxlen         = sizeof(scan_unevictable_pages),
-               .mode           = 0644,
-               .proc_handler   = scan_unevictable_handler,
-       },
 #ifdef CONFIG_MEMORY_FAILURE
        {
                .procname       = "memory_failure_early_kill",

diff --git a/mm/vmscan.c b/mm/vmscan.c
index 1a71b8b1ea3490d1f225a2f6ebb48db361825584..af72fe8e8d74478769334739647d6b41d09c59ae 100644 (file)
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -3797,66 +3797,3 @@ void check_move_unevictable_pages(struct page **pages, int nr_pages)
        }
 }
 #endif /* CONFIG_SHMEM */
-
-static void warn_scan_unevictable_pages(void)
-{
-       printk_once(KERN_WARNING
-                   "%s: The scan_unevictable_pages sysctl/node-interface has been "
-                   "disabled for lack of a legitimate use case.  If you have "
-                   "one, please send an email to linux-mm@kvack.org.\n",
-                   current->comm);
-}
-
-/*
- * scan_unevictable_pages [vm] sysctl handler.  On demand re-scan of
- * all nodes' unevictable lists for evictable pages
- */
-unsigned long scan_unevictable_pages;
-
-int scan_unevictable_handler(struct ctl_table *table, int write,
-                          void __user *buffer,
-                          size_t *length, loff_t *ppos)
-{
-       warn_scan_unevictable_pages();
-       proc_doulongvec_minmax(table, write, buffer, length, ppos);
-       scan_unevictable_pages = 0;
-       return 0;
-}
-
-#ifdef CONFIG_NUMA
-/*
- * per node 'scan_unevictable_pages' attribute.  On demand re-scan of
- * a specified node's per zone unevictable lists for evictable pages.
- */
-
-static ssize_t read_scan_unevictable_node(struct device *dev,
-                                         struct device_attribute *attr,
-                                         char *buf)
-{
-       warn_scan_unevictable_pages();
-       return sprintf(buf, "0\n");     /* always zero; should fit... */
-}
-
-static ssize_t write_scan_unevictable_node(struct device *dev,
-                                          struct device_attribute *attr,
-                                       const char *buf, size_t count)
-{
-       warn_scan_unevictable_pages();
-       return 1;
-}
-
-
-static DEVICE_ATTR(scan_unevictable_pages, S_IRUGO | S_IWUSR,
-                       read_scan_unevictable_node,
-                       write_scan_unevictable_node);
-
-int scan_unevictable_register_node(struct node *node)
-{
-       return device_create_file(&node->dev, &dev_attr_scan_unevictable_pages);
-}
-
-void scan_unevictable_unregister_node(struct node *node)
-{
-       device_remove_file(&node->dev, &dev_attr_scan_unevictable_pages);
-}
-#endif