mm: fix proc_dointvec_userhz_jiffies "breakage"

Addresses http://bugzilla.kernel.org/show_bug.cgi?id=9838

On i386, HZ=1000, jiffies_to_clock_t() converts time in a somewhat strange
way from the user's point of view:

	# echo 500 >/proc/sys/vm/dirty_writeback_centisecs
	# cat /proc/sys/vm/dirty_writeback_centisecs
	499

So, we have 5000 jiffies converted to only 499 clock ticks and reported
back.

TICK_NSEC = 999848
ACTHZ = 256039

Keeping in-kernel variable in units passed from userspace will fix issue
of course, but this probably won't be right for every sysctl.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 1 insertions, 1 deletions

diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index c5ef44ff850f..2e490a389dd2 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -1010,7 +1010,7 @@ static struct ctl_table vm_table[] = {
                 .data           = &dirty_expire_interval,
                 .maxlen         = sizeof(dirty_expire_interval),
                 .mode           = 0644,
-                .proc_handler   = &proc_dointvec_userhz_jiffies,
+                .proc_handler   = &proc_dointvec,
         },
         {
                 .ctl_name       = VM_NR_PDFLUSH_THREADS,