diff options
| -rw-r--r-- | include/linux/writeback.h | 20 | ||||
| -rw-r--r-- | mm/memcontrol.c | 12 |
2 files changed, 32 insertions, 0 deletions
diff --git a/include/linux/writeback.h b/include/linux/writeback.h index 04a3786..3b73e97 100644 --- a/include/linux/writeback.h +++ b/include/linux/writeback.h @@ -132,6 +132,26 @@ struct wb_domain { unsigned long dirty_limit; }; +/** + * wb_domain_size_changed - memory available to a wb_domain has changed + * @dom: wb_domain of interest + * + * This function should be called when the amount of memory available to + * @dom has changed. It resets @dom's dirty limit parameters to prevent + * the past values which don't match the current configuration from skewing + * dirty throttling. Without this, when memory size of a wb_domain is + * greatly reduced, the dirty throttling logic may allow too many pages to + * be dirtied leading to consecutive unnecessary OOMs and may get stuck in + * that situation. + */ +static inline void wb_domain_size_changed(struct wb_domain *dom) +{ + spin_lock(&dom->lock); + dom->dirty_limit_tstamp = jiffies; + dom->dirty_limit = 0; + spin_unlock(&dom->lock); +} + /* * fs/fs-writeback.c */ diff --git a/mm/memcontrol.c b/mm/memcontrol.c index ce113dd..c0b0406 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -4005,6 +4005,11 @@ static void memcg_wb_domain_exit(struct mem_cgroup *memcg) wb_domain_exit(&memcg->cgwb_domain); } +static void memcg_wb_domain_size_changed(struct mem_cgroup *memcg) +{ + wb_domain_size_changed(&memcg->cgwb_domain); +} + struct wb_domain *mem_cgroup_wb_domain(struct bdi_writeback *wb) { struct mem_cgroup *memcg = mem_cgroup_from_css(wb->memcg_css); @@ -4026,6 +4031,10 @@ static void memcg_wb_domain_exit(struct mem_cgroup *memcg) { } +static void memcg_wb_domain_size_changed(struct mem_cgroup *memcg) +{ +} + #endif /* CONFIG_CGROUP_WRITEBACK */ /* @@ -4624,6 +4633,7 @@ static void mem_cgroup_css_reset(struct cgroup_subsys_state *css) memcg->low = 0; memcg->high = PAGE_COUNTER_MAX; memcg->soft_limit = PAGE_COUNTER_MAX; + memcg_wb_domain_size_changed(memcg); } #ifdef CONFIG_MMU @@ -5361,6 +5371,7 @@ static ssize_t memory_high_write(struct kernfs_open_file *of, memcg->high = high; + memcg_wb_domain_size_changed(memcg); return nbytes; } @@ -5393,6 +5404,7 @@ static ssize_t memory_max_write(struct kernfs_open_file *of, if (err) return err; + memcg_wb_domain_size_changed(memcg); return nbytes; } |
