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>
This commit is contained in:
Wanpeng Li
2012-07-31 16:41:52 -07:00
committed by Linus Torvalds
parent deaf386ee5
commit 3965c9ae47
9 changed files with 40 additions and 27 deletions

View File

@@ -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;
}