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 0a931cdd4f6baaa96cdfab2e0dd668c0abef8809..2c90357c34ea4c4d81521b7bf14d669d6565cc07 100644 (file)
--- a/mm/page-writeback.c
+++ b/mm/page-writeback.c
@@ -145,9 +145,6 @@ struct dirty_throttle_control {
        unsigned long           pos_ratio;
 };
 
-#define DTC_INIT_COMMON(__wb)  .wb = (__wb),                           \
-                               .wb_completions = &(__wb)->completions
-
 /*
  * Length of period for aging writeout fractions of bdis. This is an
  * arbitrarily chosen number. The longer the period, the slower fractions will
@@ -157,12 +154,16 @@ struct dirty_throttle_control {
 
 #ifdef CONFIG_CGROUP_WRITEBACK
 
-#define GDTC_INIT(__wb)                .dom = &global_wb_domain,               \
-                               DTC_INIT_COMMON(__wb)
+#define GDTC_INIT(__wb)                .wb = (__wb),                           \
+                               .dom = &global_wb_domain,               \
+                               .wb_completions = &(__wb)->completions
+
 #define GDTC_INIT_NO_WB                .dom = &global_wb_domain
-#define MDTC_INIT(__wb, __gdtc)        .dom = mem_cgroup_wb_domain(__wb),      \
-                               .gdtc = __gdtc,                         \
-                               DTC_INIT_COMMON(__wb)
+
+#define MDTC_INIT(__wb, __gdtc)        .wb = (__wb),                           \
+                               .dom = mem_cgroup_wb_domain(__wb),      \
+                               .wb_completions = &(__wb)->memcg_completions, \
+                               .gdtc = __gdtc
 
 static bool mdtc_valid(struct dirty_throttle_control *dtc)
 {
@@ -213,7 +214,8 @@ static void wb_min_max_ratio(struct bdi_writeback *wb,
 
 #else  /* CONFIG_CGROUP_WRITEBACK */
 
-#define GDTC_INIT(__wb)                DTC_INIT_COMMON(__wb)
+#define GDTC_INIT(__wb)                .wb = (__wb),                           \
+                               .wb_completions = &(__wb)->completions
 #define GDTC_INIT_NO_WB
 #define MDTC_INIT(__wb, __gdtc)
 
@@ -682,13 +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);
 }
 
 /**
@@ -1562,16 +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);
 
@@ -1893,10 +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)
@@ -1956,7 +1965,6 @@ void laptop_mode_timer_fn(unsigned long data)
        int nr_pages = global_page_state(NR_FILE_DIRTY) +
                global_page_state(NR_UNSTABLE_NFS);
        struct bdi_writeback *wb;
-       struct wb_iter iter;
 
        /*
         * We want to write everything out, not just down to the dirty
@@ -1965,10 +1973,12 @@ void laptop_mode_timer_fn(unsigned long data)
        if (!bdi_has_dirty_io(&q->backing_dev_info))
                return;
 
-       bdi_for_each_wb(wb, &q->backing_dev_info, &iter, 0)
+       rcu_read_lock();
+       list_for_each_entry_rcu(wb, &q->backing_dev_info.wb_list, bdi_node)
                if (wb_has_dirty_io(wb))
                        wb_start_writeback(wb, nr_pages, true,
                                           WB_REASON_LAPTOP_TIMER);
+       rcu_read_unlock();
 }
 
 /*