Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel...

[karo-tx-linux.git] / mm / page-writeback.c

diff --git a/mm/page-writeback.c b/mm/page-writeback.c
index 56c0bffa9f49f6e1c7a84537bc781ce71697d42b..2c90357c34ea4c4d81521b7bf14d669d6565cc07 100644 (file)
--- a/mm/page-writeback.c
+++ b/mm/page-writeback.c
@@ -684,13 +684,19 @@ static unsigned long hard_dirty_limit(struct wb_domain *dom,
        return max(thresh, dom->dirty_limit);
 }
 
-/* memory available to a memcg domain is capped by system-wide clean memory */
-static void mdtc_cap_avail(struct dirty_throttle_control *mdtc)
+/*
+ * Memory which can be further allocated to a memcg domain is capped by
+ * system-wide clean memory excluding the amount being used in the domain.
+ */
+static void mdtc_calc_avail(struct dirty_throttle_control *mdtc,
+                           unsigned long filepages, unsigned long headroom)
 {
        struct dirty_throttle_control *gdtc = mdtc_gdtc(mdtc);
-       unsigned long clean = gdtc->avail - min(gdtc->avail, gdtc->dirty);
+       unsigned long clean = filepages - min(filepages, mdtc->dirty);
+       unsigned long global_clean = gdtc->avail - min(gdtc->avail, gdtc->dirty);
+       unsigned long other_clean = global_clean - min(global_clean, clean);
 
-       mdtc->avail = min(mdtc->avail, clean);
+       mdtc->avail = filepages + min(headroom, other_clean);
 }
 
 /**
@@ -1564,16 +1570,16 @@ static void balance_dirty_pages(struct address_space *mapping,
                }
 
                if (mdtc) {
-                       unsigned long writeback;
+                       unsigned long filepages, headroom, writeback;
 
                        /*
                         * If @wb belongs to !root memcg, repeat the same
                         * basic calculations for the memcg domain.
                         */
-                       mem_cgroup_wb_stats(wb, &mdtc->avail, &mdtc->dirty,
-                                           &writeback);
-                       mdtc_cap_avail(mdtc);
+                       mem_cgroup_wb_stats(wb, &filepages, &headroom,
+                                           &mdtc->dirty, &writeback);
                        mdtc->dirty += writeback;
+                       mdtc_calc_avail(mdtc, filepages, headroom);
 
                        domain_dirty_limits(mdtc);
 
@@ -1895,10 +1901,11 @@ bool wb_over_bg_thresh(struct bdi_writeback *wb)
                return true;
 
        if (mdtc) {
-               unsigned long writeback;
+               unsigned long filepages, headroom, writeback;
 
-               mem_cgroup_wb_stats(wb, &mdtc->avail, &mdtc->dirty, &writeback);
-               mdtc_cap_avail(mdtc);
+               mem_cgroup_wb_stats(wb, &filepages, &headroom, &mdtc->dirty,
+                                   &writeback);
+               mdtc_calc_avail(mdtc, filepages, headroom);
                domain_dirty_limits(mdtc);      /* ditto, ignore writeback */
 
                if (mdtc->dirty > mdtc->bg_thresh)