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authorDaniel Vetter <daniel.vetter@ffwll.ch>2015-03-30 16:37:08 +0200
committerDaniel Vetter <daniel.vetter@ffwll.ch>2015-03-30 16:37:08 +0200
commit6e0aa8018f9c676b115b7ca6c20a056fc57c68a9 (patch)
treeb35393574b48dcc05c99599add7f8b0015de3913 /mm/page-writeback.c
parent1ff27a3443addb19af609245b218fa510c7d37dd (diff)
parente42391cd048809d903291d07f86ed3934ce138e9 (diff)
Merge tag 'v4.0-rc6' into drm-intel-next
Backmerge Linux 4.0-rc6 because conflicts are (again) getting out of hand. To make sure we don't lose any bugfixes from the 4.0-rc5-rc6 flurry of patches we've applied them all to -next too. Conflicts: drivers/gpu/drm/i915/intel_display.c Always take the version from -next, we've already handled all conflicts with explicit cherrypicking. Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Diffstat (limited to 'mm/page-writeback.c')
-rw-r--r--mm/page-writeback.c7
1 files changed, 5 insertions, 2 deletions
diff --git a/mm/page-writeback.c b/mm/page-writeback.c
index 45e187b2d971..644bcb665773 100644
--- a/mm/page-writeback.c
+++ b/mm/page-writeback.c
@@ -857,8 +857,11 @@ static void bdi_update_write_bandwidth(struct backing_dev_info *bdi,
* bw * elapsed + write_bandwidth * (period - elapsed)
* write_bandwidth = ---------------------------------------------------
* period
+ *
+ * @written may have decreased due to account_page_redirty().
+ * Avoid underflowing @bw calculation.
*/
- bw = written - bdi->written_stamp;
+ bw = written - min(written, bdi->written_stamp);
bw *= HZ;
if (unlikely(elapsed > period)) {
do_div(bw, elapsed);
@@ -922,7 +925,7 @@ 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