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authorWanpeng Li2012-08-01 01:41:52 +0200
committerLinus Torvalds2012-08-01 03:42:40 +0200
commit3965c9ae47d64aadf6f13b6fcd37767b83c0689a (patch)
tree9896fbd841edbaa8e374b593ad0f7b96191cda5d /mm/backing-dev.c
parentmm/buddy: cleanup on should_fail_alloc_page (diff)
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mm: prepare for removal of obsolete /proc/sys/vm/nr_pdflush_threads
Since per-BDI flusher threads were introduced in 2.6, the pdflush mechanism is not used any more. But the old interface exported through /proc/sys/vm/nr_pdflush_threads still exists and is obviously useless. For back-compatibility, printk warning information and return 2 to notify the users that the interface is removed. Signed-off-by: Wanpeng Li <liwp@linux.vnet.ibm.com> Cc: Wu Fengguang <fengguang.wu@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/backing-dev.c')
-rw-r--r--mm/backing-dev.c20
1 files changed, 20 insertions, 0 deletions
diff --git a/mm/backing-dev.c b/mm/backing-dev.c
index 3387aea11209..6b4718e2ee34 100644
--- a/mm/backing-dev.c
+++ b/mm/backing-dev.c
@@ -886,3 +886,23 @@ out:
return ret;
}
EXPORT_SYMBOL(wait_iff_congested);
+
+int pdflush_proc_obsolete(struct ctl_table *table, int write,
+ void __user *buffer, size_t *lenp, loff_t *ppos)
+{
+ char kbuf[] = "0\n";
+
+ if (*ppos) {
+ *lenp = 0;
+ return 0;
+ }
+
+ if (copy_to_user(buffer, kbuf, sizeof(kbuf)))
+ return -EFAULT;
+ printk_once(KERN_WARNING "%s exported in /proc is scheduled for removal\n",
+ table->procname);
+
+ *lenp = 2;
+ *ppos += *lenp;
+ return 2;
+}