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>
diff --git a/kernel/sysctl_binary.c b/kernel/sysctl_binary.c
index a650694..65bdcf1 100644
--- a/kernel/sysctl_binary.c
+++ b/kernel/sysctl_binary.c
@@ -147,7 +147,7 @@
{ CTL_INT, VM_DIRTY_RATIO, "dirty_ratio" },
/* VM_DIRTY_WB_CS "dirty_writeback_centisecs" no longer used */
/* VM_DIRTY_EXPIRE_CS "dirty_expire_centisecs" no longer used */
- { CTL_INT, VM_NR_PDFLUSH_THREADS, "nr_pdflush_threads" },
+ /* VM_NR_PDFLUSH_THREADS "nr_pdflush_threads" no longer used */
{ CTL_INT, VM_OVERCOMMIT_RATIO, "overcommit_ratio" },
/* VM_PAGEBUF unused */
/* VM_HUGETLB_PAGES "nr_hugepages" no longer used */