path: root/mm
diff options
authorTejun Heo <tj@kernel.org>2015-03-04 10:37:43 -0500
committerJens Axboe <axboe@fb.com>2015-03-04 08:38:59 -0700
commit7d70e15480c0450d2bfafaad338a32e884fc215e (patch)
tree5f41bb2f4bb074959d30a51a1178d4c23411c2b3 /mm
parentLinux 4.0-rc2 (diff)
writeback: add missing INITIAL_JIFFIES init in global_update_bandwidth()
global_update_bandwidth() uses static variable update_time as the timestamp for the last update but forgets to initialize it to INITIALIZE_JIFFIES. This means that global_dirty_limit will be 5 mins into the future on 32bit and some large amount jiffies into the past on 64bit. This isn't critical as the only effect is that global_dirty_limit won't be updated for the first 5 mins after booting on 32bit machines, especially given the auxiliary nature of global_dirty_limit's role - protecting against global dirty threshold's sudden dips; however, it does lead to unintended suboptimal behavior. Fix it. Fixes: c42843f2f0bb ("writeback: introduce smoothed global dirty limit") Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Jan Kara <jack@suse.cz> Cc: Wu Fengguang <fengguang.wu@intel.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: stable@vger.kernel.org Signed-off-by: Jens Axboe <axboe@fb.com>
Diffstat (limited to 'mm')
1 files changed, 1 insertions, 1 deletions
diff --git a/mm/page-writeback.c b/mm/page-writeback.c
index 45e187b2d971..b4fd980a93eb 100644
--- a/mm/page-writeback.c
+++ b/mm/page-writeback.c
@@ -922,7 +922,7 @@ static void global_update_bandwidth(unsigned long thresh,
unsigned long now)
static DEFINE_SPINLOCK(dirty_lock);
- static unsigned long update_time;
+ static unsigned long update_time = INITIAL_JIFFIES;
* check locklessly first to optimize away locking for the most time