diff options
| -rw-r--r-- | mm/memcontrol.c | 93 |
1 files changed, 58 insertions, 35 deletions
diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 6d276e1a3321..7a4bd8b9adc2 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -2297,28 +2297,41 @@ static void high_work_func(struct work_struct *work) #define MEMCG_DELAY_SCALING_SHIFT 14 /* - * Scheduled by try_charge() to be executed from the userland return path - * and reclaims memory over the high limit. + * Get the number of jiffies that we should penalise a mischievous cgroup which + * is exceeding its memory.high by checking both it and its ancestors. */ -void mem_cgroup_handle_over_high(void) +static unsigned long calculate_high_delay(struct mem_cgroup *memcg, + unsigned int nr_pages) { - unsigned long usage, high, clamped_high; - unsigned long pflags; - unsigned long penalty_jiffies, overage; - unsigned int nr_pages = current->memcg_nr_pages_over_high; - struct mem_cgroup *memcg; + unsigned long penalty_jiffies; + u64 max_overage = 0; - if (likely(!nr_pages)) - return; + do { + unsigned long usage, high; + u64 overage; - memcg = get_mem_cgroup_from_mm(current->mm); - reclaim_high(memcg, nr_pages, GFP_KERNEL); - current->memcg_nr_pages_over_high = 0; + usage = page_counter_read(&memcg->memory); + high = READ_ONCE(memcg->high); + + /* + * Prevent division by 0 in overage calculation by acting as if + * it was a threshold of 1 page + */ + high = max(high, 1UL); + + overage = usage - high; + overage <<= MEMCG_DELAY_PRECISION_SHIFT; + overage = div64_u64(overage, high); + + if (overage > max_overage) + max_overage = overage; + } while ((memcg = parent_mem_cgroup(memcg)) && + !mem_cgroup_is_root(memcg)); + + if (!max_overage) + return 0; /* - * memory.high is breached and reclaim is unable to keep up. Throttle - * allocators proactively to slow down excessive growth. - * * We use overage compared to memory.high to calculate the number of * jiffies to sleep (penalty_jiffies). Ideally this value should be * fairly lenient on small overages, and increasingly harsh when the @@ -2326,24 +2339,9 @@ void mem_cgroup_handle_over_high(void) * its crazy behaviour, so we exponentially increase the delay based on * overage amount. */ - - usage = page_counter_read(&memcg->memory); - high = READ_ONCE(memcg->high); - - if (usage <= high) - goto out; - - /* - * Prevent division by 0 in overage calculation by acting as if it was a - * threshold of 1 page - */ - clamped_high = max(high, 1UL); - - overage = div64_u64((u64)(usage - high) << MEMCG_DELAY_PRECISION_SHIFT, - clamped_high); - - penalty_jiffies = ((u64)overage * overage * HZ) - >> (MEMCG_DELAY_PRECISION_SHIFT + MEMCG_DELAY_SCALING_SHIFT); + penalty_jiffies = max_overage * max_overage * HZ; + penalty_jiffies >>= MEMCG_DELAY_PRECISION_SHIFT; + penalty_jiffies >>= MEMCG_DELAY_SCALING_SHIFT; /* * Factor in the task's own contribution to the overage, such that four @@ -2360,7 +2358,32 @@ void mem_cgroup_handle_over_high(void) * application moving forwards and also permit diagnostics, albeit * extremely slowly. */ - penalty_jiffies = min(penalty_jiffies, MEMCG_MAX_HIGH_DELAY_JIFFIES); + return min(penalty_jiffies, MEMCG_MAX_HIGH_DELAY_JIFFIES); +} + +/* + * Scheduled by try_charge() to be executed from the userland return path + * and reclaims memory over the high limit. + */ +void mem_cgroup_handle_over_high(void) +{ + unsigned long penalty_jiffies; + unsigned long pflags; + unsigned int nr_pages = current->memcg_nr_pages_over_high; + struct mem_cgroup *memcg; + + if (likely(!nr_pages)) + return; + + memcg = get_mem_cgroup_from_mm(current->mm); + reclaim_high(memcg, nr_pages, GFP_KERNEL); + current->memcg_nr_pages_over_high = 0; + + /* + * memory.high is breached and reclaim is unable to keep up. Throttle + * allocators proactively to slow down excessive growth. + */ + penalty_jiffies = calculate_high_delay(memcg, nr_pages); /* * Don't sleep if the amount of jiffies this memcg owes us is so low |